casting-msg - 3/1/08 Casting pewter and other metals. NOTE: See also these files: metals-msg, metalworking-msg, metalworking-FAQ, tokens-msg, belts-msg, fasteners-msg, soapstone-msg, pewter-msg. ************************************************************************ NOTICE - This file is a collection of various messages having a common theme that I have collected from my reading of the various computer networks. Some messages date back to 1989, some may be as recent as yesterday. This file is part of a collection of files called Stefan's Florilegium. These files are available on the Internet at: http://www.florilegium.org I have done a limited amount of editing. Messages having to do with separate topics were sometimes split into different files and sometimes extraneous information was removed. For instance, the message IDs were removed to save space and remove clutter. The comments made in these messages are not necessarily my viewpoints. I make no claims as to the accuracy of the information given by the individual authors. Please respect the time and efforts of those who have written these messages. The copyright status of these messages is unclear at this time. If information is published from these messages, please give credit to the originator(s). Thank you, Mark S. Harris AKA: THLord Stefan li Rous Stefan at florilegium.org ************************************************************************ From: sclark at epas.utoronto.ca (Susan Carroll-Clark) Newsgroups: rec.org.sca Subject: Pewter Casting article... Date: 4 Jul 1994 03:12:10 GMT Organization: University of Toronto -- EPAS Greetings... Hot off the presses, here's the promised article. Happy reading... Nicolaa/Susan sclark at epas.utoronto.ca ******************************************************************************* Beginning Pewter Casting by Lady Nicolaa de Bracton of Leicester Materials needed: --Pewter (bar or chip form). --heat source (propane torch, stovetop element, casting pot, campfire) --Container to heat pewter in (small pot, ladle, etc.) --material for mold (preferably soapstone) --rubber bands --carving tools (dental or woodcarving tools are best, but virtually anything will carve soapstone) --sandpaper --files (microfiles are most useful) --tongs or clamps --bowl of cold water --pliers --towels or oven mitts A note on pewter: Pewter sold today in craft stores for jewellery-making is usually lead free; it is an alloy of copper, tin, and antimony. A number of companies also sell pewter for miniature casting; this may not be lead-free. If in doubt, ask. Current going price for one pound of lead-free pewter in the Toronto area is $10-$17 CDN. Craft stores are often overpriced; ask your local SCA jewllery - and metalworkers for sources. Step 1: The Mold Soapstone is the best material for pewter casting. Molds made of soapstone rarely break down even after a hundred or more castings; the molds retain heat quite well, which makes for good, clean casts; and soapstone can also be carved quite finely and is very simple to work. If multiple castings are not needed and you have no source for soapstone, plaster molds may also be used. Soapstone can be obtained from lapidary craft stores; if you are having problems finding a source, check with your local mineral club or art school. For a simple mold, you will need two pieces of soapstone which fit flush. The best way to ensure that they are flush is to place a piece of sandpaper on a flat surface and run the pieces over it repeatedly. (Warning! This produces lots of very fine dust. You may wish to wear a mask). Once your pieces are ready, you can carve your mold. This is entirely up to you. Dental tools are nice for this and can be obtained either from your dentist (who might give you a funny look at first) or from surplus stores. Lapidary and jewellery-making stores sometimes stock them as well, but they tend to be overpriced there. Some hints: First, make sure that your carving is no more than an inch or so from what will be the top edge of your mold, or else the pewter will be cool before it ever reaches the actual mold section. Second, make sure that there are no overhanging ledges on your mold that could trap the pewter; make sure that the edge of your piece is either straight or slopes in slightly towards the bottom of the mold. Finally, do not carve a lot of detail onto your piece until you have done a test casting of the basic shape. Next, you need to carve a channel or *sprue* from the top edge of your piece of soapstone to the mold itself. The sprue should be placed opposite from the area with the most detail, so that the pewter will flow downward to that area first. Your sprue should be in the shape of a funnel, with the mouth at the edge of the piece of soapstone and the neck close to the mold itself, and the reservoir thus created should hold about as much pewter as the mold itself will. The larger the piece, the bigger the sprue and reservoir. Once you have cast your piece, you will clip off the sprue with pliers or cutters and file the raw edge. These instructions will result in a simple one-piece mold with a back piece. There are such things as two- and three-piece molds, which allow one to cast in three dimensions, but they are not suitable for beginners. Step 2: Heating the pewter There are many ways to do this. I place the pewter in a ladle and train a propane torch on it (keep the flame low--it won't take that long to melt). You can also find a small sauce-pot and heat it on the stove, buy a special casting pot, or even use the hot coals of a campfire. Experiment around and find what works best for you. The most important thing is that you get the pewter hot enough to flow through your mold. Pewter is ready to pour when it has melted and acquired a blackened colour on the surface. You will want to either have a container you can pour the pewter directly into the mold from, or a ladle or spoon to dip into the pewter for this purpose. The shorter the distance from the heat source to the mold, the better; this is why I like to heat up my pewter right in the ladle. Step three: Pouring the Pewter Rubber-band the back of your mold to the front. (You could use c-clamps instead, but I find them more time-consuming). At this point it helps to have an assistant, but it is possible to manage on your own. Using tongs, clamp the mold together firmly, and then pour the pewter into the reservoir. Keep the piece clamped until the pewter sets. This happens when the molten pewter loses its shiny, mercury-like appearance and turns a dull silver; it only takes a few seconds. At this point, you can remove the clamp, take off the rubber bands, and pop the casting out. Using the pliers, place this in the bowl of water. DO NOT TOUCH IT! It is still VERY hot. Watch your mold as well -- as you continue to cast, the mold itself will heat up, which will aid in subsequent casts; hold the mold with a towel or oven mitts. The first casting out of a mold is often substandard because the mold has not yet heated up. Unsuccessful casts and the sprue parts of molds can be re-fed into your pot or ladle of pewter. Make sure, however, that they are THOROUGHLY DRY. Water in the melting pot can cause the pewter to spatter, which could cause nasty burns. To finish your piece, clip off the sprue with pliers or cutters, and file the raw edge. You are done! After a few test casts, you will probably wish to fine-tune your mold. Here are a few common problems and possible solutions: Problem: Mold does not completely cast This could be caused by one of two things: either your pewter is not hot enough, which results in the pewter setting before it has reached all of the mold; or your sprue is either too long or too narrow, which causes the pewter to freeze up before it can reach the mold. Molds which have not yet completely heat up also often do not completely cast. Problem: Pewter gets stuck in mold Your mold probably has undercutting--a sort of overhanging ledge that is blocking the easy removal of the cast. File the sides so they are either straight or slope slightly inward. Problem: Pewter squirts out the side of the mold Either your two blocks do not fit flush, or you are not clamping them tightly enough. Problem: Loops or other details will not cast Loops (for hanging purposes) are best put at the bottom of molds, so that gravity will pull the pewter into them. If details will not cast after repeated attempts, and none of the usual solutions (widening the sprue, making sure the pewter is very hot) do not work, you may wish to change the location of the sprue. You can use putty to close up the old sprue and carve a new one. The science of pewter casting is still fairly new to me, but having survived casting 130 feast tokens over the space of two evenings and one afternoon for an event I recently autocratted, I can honestly say that any idiot can do it; I am proof. Of course, I had the help of the very talented Lady Kestrel of Cadfan, who gave the original talk on this topic in my home canton and who loaned me some of her equipment and guided me through. If you can find an experienced caster to help, I highly recommend this approach -- youUll save a lot of trial and error. Good luck! copyright 1994 by Susan Carroll-Clark. Permission is granted for publication in any SCA-related newsletter, provided that the author is credited and receives a copy. From: Susan Carroll-Clark (7/3/94) To: Mark Harris RE>Site Tokens Greetinngs-- I got my first lot of pewter from a craft supply store--a fairly specialized one that also deals in woodworking and lapidary supplies. If you know any SCA metaworkers, see if they know any cheaper sources--craft stores tend to be pricey. Soapstone you can get in the same sorts of places. If there's an art school in your town, you might ask them if they know sources for these sorts of things. The tokens themselves were about nickel-thick and quarter-sized in diameter. The loop was part of the mold-- it looks like a little "handle" on top of the round bit. Basically, here are the steps to follow: 1. Sand down your two sandstone pieces until they lie flat against each other. 2. Carve your mold with whatever tools you wish. Soapstone carves really easily. For best results, put the mold no more than an inch from the top edge of your stone. Beware of undercutting: i.e., when there is a "ledge" in your mold that will make the pewter get stuck in the mold. 3. Carve a sprue--a channel leading to the mold, and a reservour for the pewter to flow into. What you should end up with is a funel-shaped channel leading to your mold. 4. Rubber band the mold to the back piece. 5. Heat up the pewter. It has to get nice and hot, though it melts fairly quickly. I just have a cheap ladle and turn the propane torch on it.When it's melted and starts to turn black, it's ready to pour. 6. Using tongs, clamp onto the mold and then pour in the pewter. (2 people helps). 7. When the pewter on the top of the mold cools, you can pop the mold. Pewter is ready to pop when it loses its shiny appearance. Don't touch it, though--pop it into a dish of cold water first. 8. The pewter should just pop out, if you have managed to avoid undercutting. Soapstone ia very similar in texture to talcum and so the pewter does not naturally stick to it. It's kind of hard to describe the process. I had it shown to me--you should check around and see if there's anyone who can do this for you. everyone has their own techniques, too--some people heat up the pewter right on the stove (I can't get it hot enough this way) and some have special pots for this (which I hope to acquire eventually). Good luck-- Nicolaa/Susan sclark at epas.utoronto.ca Newsgroups: rec.org.sca From: eadengle at watcgl.uwaterloo.ca (Ed "Cynwrig" Dengler) Subject: Re: Pewter Casting article... Organization: University of Waterloo Date: Tue, 5 Jul 1994 16:13:09 GMT Greetings to the Rialto! Nicolaa recently posted a great article on pewter casting. As another newby who has just done a set of appreciation tokens in pewter, I would lie to add a few points. Nicolaa writes: >A note on pewter: Pewter sold today in craft stores for >jewellery-making is usually lead free; it is an alloy of copper, tin, >and antimony. A number of companies also sell pewter for miniature >casting; this may not be lead-free. If in doubt, ask. Current going >price for one pound of lead-free pewter in the Toronto area is $10-$17 >CDN. Craft stores are often overpriced; ask your local SCA jewllery >- and metalworkers for sources. Another source of pewter recommended by Master Sylard of Eagleshavn is to use lead-free solder sold for soldering pipes. The big advantage of using this is that lengths of solder wire can be snipped easily to the quantity of pewter desired. Note that the bigger the spool of solder, the cheaper it gets (I bought 500g = 1.1pounds for $11). This can be bought from any plumbing supply or hardware supply store (warning: most solder sold contains lead, so be sure to check the label to determine the solder mixture). >Step 2: Heating the pewter >There are many ways to do this. I place the pewter in a ladle and >train a propane torch on it (keep the flame low--it wonUt take that >long to melt). You can also find a small sauce-pot and heat it on the >stove, buy a special casting pot, or even use the hot coals of a >campfire. Experiment around and find what works best for you. The >most important thing is that you get the pewter hot enough to flow >through your mold. Pewter is ready to pour when it has melted and >acquired a blackened colour on the surface. You will want to either >have a container you can pour the pewter directly into the mold from, >or a ladle or spoon to dip into the pewter for this purpose. The >shorter the distance from the heat source to the mold, the better; >this is why I like to heat up my pewter right in the ladle. The method I used was to obtain a small Turkish coffee making pot made from a heavy stainless steel, and then used a stove as a heat source. This has the advantages that you can melt small amounts (say for only one or two castings each time you pour), and that the pot sits nicely on the stovetop without falling over. Another advantage is that these are easily obtained from any specialty cookware supply store for a reasonable price (note that you do NOT want to make coffee in it after using it for pewter casting). >Step three: Pouring the Pewter >Rubber-band the back of your mold to the front. (You could use >c-clamps instead, but I find them more time-consuming). At this point >it helps to have an assistant, but it is possible to manage on your >own. Using tongs, clamp the mold together firmly, and then pour the >pewter into the reservoir. Keep the piece clamped until the pewter >sets. This happens when the molten pewter loses its shiny, >mercury-like appearance and turns a dull silver; it only takes a few >seconds. At this point, you can remove the clamp, take off the rubber >bands, and pop the casting out. Using the pliers, place this in the >bowl of water. DO NOT TOUCH IT! It is still VERY hot. Watch your >mold as well -- as you continue to cast, the mold itself will heat up, >which will aid in subsequent casts; hold the mold with a towel or oven >mitts. The first casting out of a mold is often substandard because >the mold has not yet heated up. If you use reasonable size soapstone pieces, I found that you could just hold the front and backs together with no problems. To do this, you WILL need heavy gloves or oven mitts, since the stones get very hot as Nicolaa has warned. >Problem: Mold does not completely cast >This could be caused by one of two things: either your pewter is not >hot enough, which results in the pewter setting before it has reached >all of the mold; or your sprue is either too long or too narrow, >which causes the pewter to freeze up before it can reach the mold. >Molds which have not yet completely heat up also often do not >completely cast. One solution I have to warming up the molds is to mold 2 or 3 pieces directly with no backing (ie. just lay your mold on the stove with the mold facing upwards and no backing, and just pour the metal on the mold). This will produce an unusable cast that goes back into the meltpot, but which has now warmed up the mold very nicely. One warning when carving the molds: do NOT use water to flush away any dust created by the carving, instead use an old toothbrush that is dry. The reason for this (which I found to my dismay the first time I did castings) is that the water will get into the soapstone and will not come back out. When the hot pewter starts getting poured (which melts at a temperature of 200-250 degrees Celsius), the water is heated up and turns to steam (which occurs at 100 degrees Celsius). This has the unpleasent effect of created a very small vapour explosion which starts to disintegrate your mold as pieces of soapstone start to flake off. Good luck to any who want to try casting! Cynwrig From: dlc at fc.hp.com (Dennis Clark) Newsgroups: rec.org.sca Subject: Re: Pewter Casting article... Date: 6 Jul 1994 23:34:44 GMT Organization: Hewlett-Packard Fort Collins Site Depending upon how much you want to spend, bullet "hot-pots" can be had for the $50.00 range at auctions and estate sales. I have two that I got from Thrifty-nickel type rags and they both have thermostats on them. I get my pewter for about $6.00 US a pound (in 4 pound sets) from a place in Albuquerque NM. They are only a wholesale outfit so I go through a local shop that I have befriended. This stuff melts quite a bit hotter than the 200-250 degree metal talked about here, its more like 400-450 by my estimates (assuming my thermostat is correct!) This article on soapstone casting is pretty cool, I have been doing things via sand casting for years, up to making rings as an experiment right now - I'll let others know how this works out if anyone is interested... On the less than period side, its also neat to make an entire miniature's army yourself by using the "Prince August" or other somesuch molds and doing it in pewter - almost seems a shame to paint them! Darn I wish that I could afford one of those vaccuum casting vulcanized rubber setups!!! Kevin ------------------------------------------------------------------------------ | Dennis Clark (303)229-4313 telnet 1-229-4313 email dlc at fc.hp.com | | Hewlett Packard ESD Perf. Lab, 3404 East Harmony Rd. Ft. Collins CO 80525 | ------------------------------CUT HERE---------------------------------------- From: Joyce Miller <jmiller at genome.wi.mit.edu> Newsgroups: rec.org.sca Subject: Re: Pewter Casting article... Date: 5 Jul 1994 16:54:35 GMT Organization: Whitehead Institute for Biomedical Research In article <2v7uma$fg4 at alpha.epas.utoronto.ca> Susan Carroll-Clark, sclark at epas.utoronto.ca writes: >For a simple mold, you will need two pieces of soapstone which fit >flush. The best way to ensure that they are flush is to place a piece >of sandpaper on a flat surface and run the pieces over it repeatedly. >(Warning! This produces lots of very fine dust. You may wish to wear >a mask). Please note that soapstone is very similar to asbestos. People using the stuff should *ABSOLUTELY* wear a mask, and should clean up the dust with a damp paper towel. Vaccuuming it up will send it through the filter, and suspend it in the air. -- Ursula From: tip at lead.aichem.arizona.edu (Tom Perigrin) Newsgroups: rec.org.sca Subject: Re: Pewter Casting article... Date: 5 Jul 1994 17:35:21 GMT Organization: Department of Chemistry Susan Carroll-Clark wrote: [much good information snipped out] > Step 1: The Mold Good My Lady, I have turned my hand unto casting in various metals, an it pleases thee, I should like to mention one other fashion of mold making that may satisfy the needs of many another. Tis true that for casting small objects with various and sundry fiddly bits, such as would be a token, then a soapstone mold mayhaps will serve the best. But for larger and more mundane objects, such as a spoon, a sand mold has much to recommend it. I think me that for a spoon this may be especially true, for that I myself would dispair of carving the mold so that the two sides of the bowl of the spoon would come evenly close, and not have the bowl be neither too thick nor too thin. But, an one has a spoon which pleases thee, then thou cans't use the sand mold to reproduce it to thy hearts content. The surface shall be slightly rough, and the finest detail shall be lost, but with files, punches, hammer, and patience one can remedy these small problems. I'faith, I myself have several spoons which I did but lightly buff, and they serve most well. From: ayotte at milo.UUCP (Robert Arthur Ayotte) Newsgroups: rec.org.sca Subject: Pewter (Brittannia) Date: 4 Jul 1994 01:59:00 -0400 Organization: the internet I would add some things on casting and working pewter. First lead free pewter (often called Britannia, which now is the lead free form of pewter) is sometimes a mix of only tin and antimony. There are many alloys available but all work in a similar fashion. A good source for these metals is NEY metals out of NY, and ARE inc in VT. They also carry a large supply of other metals such as copper and nickelsilver in different sheet and wire. I have dealt with ARE and find them very good and fast in filling orders. In addition they carry Red Brass and I know ARE carries Merlins Gold (another brass alloy very similar in color to gold a much better match than standard brass). Molds - There's a dental mold making material that will take the temperatures of pewter for small castings. It's a fluid that sets and one can take molds (don't forget a release coat) and then do flat casting. There aer other rubber (silicon) materials that will take the temps of pewter as well. This is most useful for small scale castings. Sand casting, cuttelbone and charcoal blocks (the jewelr grade) will also work for short work molds. The results are sometimes less accurate but will serve. Stay away from plaster of paris as it must be baked dry and in the small experiance I have had with it it's not a very satisfactory mold for this application. You can also do a more extreme process of mold making as the pewtersmiths (silversmiths) used to and make a hard coat sort of mold. I would reffer folks to "Treaties of Benvenuto Cellini on goldsmithing and sculpture" His discriptions of mold build up for larger works are some of the best I have read and can be down sized. Also the works of Tim McCreight are of great value, here his book "Practical Casting" ($10.95 US) should be very useful, but one of the most useful is his other book "the Complete Metalsmith". Heating - Pewter is sensative to overheating. The Antimony tends to seperate (that's the peacock color layer that can develop). You want it just hot enough to melt. I use old cast iron pots and pans cleaned very well and then brought to a very high temp. There are electromelt devices available. Horace, Northshield Newsgroups: rec.org.sca From: Ginny Beatty <virginia.l.beatty at daytonOH.NCR.COM> Subject: Pewter - other casting materials Organization: AT&T - GIS Date: Tue, 5 Jul 1994 17:41:56 GMT > Robert Arthur Ayotte writes: > I would add some things on casting and working pewter. [snip] > Molds - There's a dental mold making material that will take the >temperatures of pewter for small castings. It's a fluid that sets and one >can take molds (don't forget a release coat) and then do flat casting. >There aer other rubber (silicon) materials that will take the temps of >pewter as well. This is most useful for small scale castings. > Sand casting, cuttelbone and charcoal blocks (the jewelr grade) will >also work for short work molds. The results are sometimes less accurate but >will serve. Stay away from plaster of paris as it must be baked dry and in >the small experiance I have had with it it's not a very satisfactory mold >for this application. [snip] I recently took a class on pewter casting at the Known World A&S Symposium. Lady Caitlin (the teacher) taught the class using cuttlefish bone as the casting medium. Granted, the detail wasn't great, but it was quite a rewarding experience for those who have not cast metal before (read- Gwyneth learned a new trick! Cool!:>). She also recommended using Investment Plaster as a casting medium. This is not the same as Plaster of Paris. Other pewter- and silver-smiths I know use Bondo as a casting medium with fairly successful results. Tim McCreight's book "the Complete Metalsmith" is a really useful book. Horace and Nicolaa, thank you for the article and supplementary information posted here. Gwyneth Banfhidhleir Ohio/Kentucky Regional MoA Midrealm From: branwen at ossi.com (Karen Williams) Newsgroups: rec.org.sca Subject: Re: Pewter Casting article... Date: 8 Jul 1994 15:24:05 -0700 Organization: Fujitsu America, Inc. sclark at epas.utoronto.ca (Susan Carroll-Clark) writes: >A note on pewter: Pewter sold today in craft stores for >jewellery-making is usually lead free; it is an alloy of copper, tin, >and antimony. A number of companies also sell pewter for miniature >casting; this may not be lead-free. If in doubt, ask. You can also get pewter in hardware stores. >Step 1: The Mold >Soapstone is the best material for pewter casting. Molds made of >soapstone rarely break down even after a hundred or more castings; >the molds retain heat quite well, which makes for good, clean casts; >and soapstone can also be carved quite finely and is very simple to >work. If multiple castings are not needed and you have no source for >soapstone, plaster molds may also be used. Soapstone can be obtained >from lapidary craft stores; if you are having problems finding a >source, check with your local mineral club or art school. Another way to make a mold, particularly if you want to copy something you already have, is to buy molding compound from a hobby store. This comes in two parts, the compound and the catalyst. You make a frame (a four-sided "fence") out of cardboard, set it on a firm surface, and fill it about half-way up with PlayDoh (don't use white; the chemicals to color it will mess up your compound). Put your object (your button, your site token carved out of children's modelling clay that hardens in the oven, etc.), in the PlayDoh so that half of it sticks out, and pour the prepared molding compound into the frame, so that it covers the object about two inches deep. Let it harden overnight, then flip the frame over, take out the PlayDoh, put Vaseline on the half that's done, and pour in more molding compound. I've obviously left out lots of steps, like how to prepare the molding compound (but that should be covered in the directions of the kind that you buy), and the brand name of the modelling clay I'm talking about (you'll know it when you see it in a craft store). I like this approach as it usually takes me several tries to get the sculpting right, and it's very easy for a beginner to do. Branwen ferch Emrys The Mists, The West From: corliss at hal.PHysics.wayne.EDU (David J. Corliss) Newsgroups: rec.org.sca Subject: Pewter casting Date: 7 Jul 1994 10:03:43 -0400 Organization: the internet Sean McAy observes: > (Pewter) has a low mwlting point, which makes using paper molds > theoretically possible (papers burning point is higher than pewters > melting point). Two things must be remembered here: first: you need to heat metal well above the melting point if you are going to cast with it or it will begin to freeze the moment it is removed from the heat, _before_ it fills the mold. (Yes, I know you can heat the mold. I simply wish to point out that that it would be best to raise the temperature well above the melting point rather than try to avoid losing any heat.) Also, it should be observed that paper is basicly just high-powered sugar. As such, it is highly subject to _dessication_: if you bring it into contact with any strong dessicating agent, be it chemical (e.g., highly concentrated sulfuric acid) or physical, such as high heat, the water in the sugar will be taken away, leaving only ash. Even if a paper mold did not catch fire, it would still turn to ash. ....this has been a public service message from the Middle Kingdom College of Sciences..... From: lazurus106 at aol.com (Lazurus106) Newsgroups: rec.org.sca Subject: Re: Pewter casting Date: 10 Jul 1994 23:33:01 -0400 corliss at hal.PHysics.wayne.EDU (David J. Corliss) writes: casting pewter will turn paper mold into ash. Wrong kemosabee. I use index cardstock regularly to cast pewter nose pieces for muzzel loaders it scorches a might but it provides excellent service. More on Pewter Casting by Niccola Sebastiani --------------------------------------------------------------------------- There is an authentic solution for how to hold the pieces of a stone mold together when casting and make sure that the sides are aligned every time. Using this technology also makes the three-piece molds you need to make brooches with pins just about as easy as two-piece molds, and makes casting really fast. Here goes (and I hope I can explain this clearly): You are going to make metal locating pins that come out of one piece of stone and fit into depressions in the other. When you have prepared your stones so they fit together cleanly, mark a couple of places on the stone that you intend to do the most intricate work on - the "front" of your piece (if there is no front, it doesn't make any difference which one you drill first). Then remove some material to make the depressions. I use a cutter (in a drill) that makes a sort of rounded cone-shaped hole about a quarter-inch across and three-eighths or a quarter-inch deep. These holes should be a quarter inch in from the edge, give or take. Then mark the spots on the other piece of stone that will be pressed against these holes. Using a drill slightly smaller than the hole you made for the female part of this "lock". Drill from the face of the second piece of stone about halfway through the stone. Then turn the stone and drill from the nearest edge straight into the stone to meet the hole you just drilled, forming an L-shaped hole. Go back to the fist pice and cut a thin line from the edge of the hole to the nearest edge of the stone (this is to give the air in the hole someplace to go when you pour your pins). Now line the two halves of the mold up carefully. Rubber band them together. (This is the last time you will have to rubber band or clamp them.) Melt some lead in your usual pot for melting the pewter. [(Please take all reasonable precautions here - ventilate, keep your melt time as short as possible, clean out your ladle after you finish with the lead, keep the lead separate from the pewter - it's shiny and pretty too when it's newly poured.) You can probably buy lead as fishing sinkers, if nothing else. You are using lead to make your pins because its melting temperature is higher than that of pewter, and you want your pins to stand up, no matter how hot your mold gets.] Holding the mold in a protected hand, pour molten lead into the holes on the side of the mold. When you take the rubber band off, you should have rounded pins sticking out of the back of your mold that fit directly into the depressions in the front. Using these pins to align the parts of the mold makes pouring very simple and quick. I wear an insulated glove (bought at a welding shop) on the hand I hold the mold in and a lighter glove on the hand I handle the ladle with. You pour, set the ladle down, open the mold with both hands (holding it fairly close to the table surface, if you want to preserve its life), tip the casting out, close the mold, and pick up the ladle again. I can pour by myself at a rate of a casting every ten seconds (in the short run) once the mold is hot. I apologize if this explanation is not clear. If you will look at almost any mold that is depicted in an archeological book (the London Dress Accessories book shows a mold, as does the Salisbury Museum catalog of pilgrim signs) you will see the pins, the depressions or the place where the pins have broken out. Breaking is not, incidentally, a thing I have had any problem with. Here is one other tip, I just thought of in describing the casting. Once you have poured the metal into the mold, it freezes first in the mold, then gradually freezes up through the button. If, instead of standing there waiting for the button to freeze, you pour resolutely, filling up your mold, then tip the metal from the button back into the pot or ladle while it is still hot you will: keep the mold cooler longer, save fuel to remelt the button, cast more quickly, and (depending on the mold) save considerable time in clean up. --------------------------------------------------------------------------- I would be awfully glad to see (and own examples of) the casting done by other SCAjuns. I will gladly trade my pieces for yours. Please contact me at: Marianne Hansen, Proprietrix 21-B E. Circular Ave. Paoli, PA 19301 610-407-0266 billy at billyandcharlie.com. http://www.billyandcharlie.com. [This address and email info has been updated - Stefan 6/24/02] From: jhrisoulas at aol.com (JHrisoulas) Newsgroups: rec.org.sca Subject: Documentation Date: 5 Apr 1995 16:04:15 -0400 As for documentation try "From Viking to Crusader" they have mention of both soapstone and clay moulds found in various grave sites throughout Europe. It's ISBN is0-8478-1625-7, by Roesdahl and Wilson, Rizzoli, NY 1992.. Hope that this helps. Your servant, Atar Bakhtar mka Dr. J.P. Hrisoulas From: sniderm at mcmail2.cis.McMaster.CA (Mike Snider) Newsgroups: rec.org.sca Subject: Re: Documentation Date: 8 Apr 1995 11:16:49 -0400 Organization: McMaster University, Hamilton, Ontario, Canada. Greetings, I have made a number of stone molds for casting buttons and pilgrim tokens. If she has the Museum of London Dress Accessories book, that is a great source but she may want to track down the following. Pilgrim Souvenirs and Secular Badges By Brian Spencer ISBN 0 947535 128 Medieval Pilgrim and Secular Badges by Michael Mitchiner I would recomment entering in the dress acc. category rather than as a metal working entry if the criteria where you are is anything like it is here in the Middle Kingdom. I am currently working on criteria for stone casting, but it won't be in use for a while. If she has any sources to share or needs any help, please have contact me directly by E-mail. I would love to hear from fellow casters. Elizabeth Cadfan From: cmhelm at artsci.wustl.EDU (Catherine Marie Helm) Newsgroups: rec.org.sca Subject: Re: Documentation Date: 8 Apr 1995 21:17:40 -0400 Organization: College of Arts and Sciences -- Washington University, St. Louis, Missouri, USA I missed the discussion on stone molds - dissertation do that to a person's spare time. I have one good reference, though the book is damned rare: p.16, figs 12 and 13 Sericite molds for casting silver pendants 12th Century, photos and discussion on molds from the Kiev State Museum, in: Russion Applied Art of the 10th-13th Centuries B. A. Rybakov Aurora Art Publishers, Leningrad, 1971 also see p. 123 of Dress Accessories. Authors Egan and Pritchard Her Majesty's Stationery Office, London, 1991 This is a brief discussion of molds but no pictures (though the multipice ceramic mold on p.122 is fascinating!). hope this is a help ttfn, Twcs From: wmclean290 at aol.com (WMclean290) Newsgroups: rec.org.sca Subject: Re: If not buttonholes, then what? Date: 18 Dec 1995 16:58:39 -0500 Organization: America Online, Inc. (1-800-827-6364) In article <francis-1712952227450001 at tigana.microserve.com>, francis at tigana.microserve.com (John [Francis] Stracke) writes: >Also, what sort of buttons are acceptable? I'm pretty sure little white >balls are OK, but they're kind of boring. :-) Yes, buttonholes are period for the 14th c.. Cloth and cloth covered buttons are well documented for the same period., in the same fabric as the garment. The modern kits for cloth covered buttons are an easy way to get the right general effect, although for maximum authenticity you can make them yourself. "Medieval Finds from Excavations in London. Vol. 4: Textiles and Clothing", Crowfoot et al, has really good info. Vol. 3 from the same series, "Dress Accessories", Egan and Pritchard, has metal buttons from the same period, usually cast and always made with shanks (as opposed to being pierced with holes like a modern shirt button. Marianne Hansen casts intensely cool reproductions of several of those buttons in pewter from handmade soapstone molds. She also makes buckles, fittings, belt mounts, badges, pins and spoons. Neat stuff! [Contact info is: Marianne Hansen, Proprietrix 21-B E. Circular Ave. Paoli, PA 19301 610-407-0266 billy at billyandcharlie.com. http://www.billyandcharlie.com. This address and email info has been updated - Stefan 6/24/02] One interesting detail: On all of the London finds the buttons are sewn to the very edge of the garment, rather than set slightly back from the edge as in modern garments. You can see the same detail in many paintings from the 14th and 15th c. if you look closely. Will McLean/Galleron de Cressy From: sjaqua at ix.netcom.com(Scott Jaqua ) Newsgroups: rec.org.sca Subject: Re: Casting with soapstone molds Date: 21 Jun 1996 14:08:05 GMT Dennis Loyer <dloyer at earthlink.net> writes: > Try requesting a catalog from TSI (800) 426-9984, They carry lead-free > pewter in wire, sheet, and nuggets (for casting). They also >carry just >about every jewlery and casting tool, book, or supplies you may ever >need. They also carry gold, silver, and copper in the same forms as their >pewter, as well as precious stones and beads. Need a centrigigal casting >machine for lost wax casting? They got it, and their prices are fairly >reasonable. Don't forget they would carry a vacuum caster as well. Having used a centrifugal caster when a flask fails and have it sling molten bronze about, I MUCH prefer my vacuum caster. Matter of fact, anybody interested in the old centrifugal caster? Allesaundra de Crosthwaite mka Sandra Jaqua From: Andrew Lowry <alowry at wchat.on.ca> From: Mike Snider <sniderm at mcmail.CIS.McMaster.CA> To: Mark Harris Date: Wed, 26 Jun 1996 00:52:45 -0400 (EDT) Subject: Re: pewter casting Greetings, Mistress Nicolaa is quite correct in telling you that the practice of casting pewter in stone moulds is Medieval, but it actually predates Sca period by quite a while as well. The Norse used this technique to great effect, but the trade in buttons and pilgrims badges peaked in the 1200-1500s. I have had the opportunity to handle a great many medieval badges and moulds during my travels in Europe, but unfortunatly such articles are scarce or absent from North American museum collections. There are, however, several good books on the subject available. If you send me your address I can mail you a copy of Getting Started in Stone Casting which has examples of period techniques for casting, illustrations of extant peices and a bibliography of source books. As you are an experienced metalworker, some of the information may be stuff you already know, but it might be worth it for the pictures. If I can be of any further help about sources, techniques etc.. please feel free to contact me directly. I read my mail fairly regularly. If you are going to War, I will be merchanting and doing some pouring in my booth. Drop by with your moulds. I always enjoy talking shop. Your servant, Mistress Elizabeth Cadfan (Kes) From: Mike Snider (6/26/96) To: Mark Harris RE>pewter casting Greetings, I will put the booklet in the mail today. I live in Hamilton, Canada, so it may take more than a week to get to you. Don't worry about the expense, it is just a small booklet to get people started. I hope you can make it to War. I am not sure if I was the person you spoke to. There are two of us working at this scale in this field. One is Mistress Nicola from the East (not De Bracton) who is a large short woman with dark hair. I sell under the name Fettered Cock Pewters and Wife of Bath Giftwear both. I am petit, very blond and usually sunburnt at Pennsic. Do drop by the shop if you can. I will be bringing quite a number of moulds to War which you may enjoy pouring to see how they work. Is the melting pot you have for bullets? I tried them and found it hard to get hot enough for many of my moulds. I have cast over a camp fire, but again, it was hard to keep the heat up. Charcol was what they used in period, but it is expensive and not environmentally friendly for a city dweller like me. I use an iron ladle over a propane burner and this works really well and is very portable. Have a local smith or armourer make you up a ladle or try the flea markets. you may get lucky. Stone is always a hassle to find. Try to find stone without too many inclusions (the hard nobs) by spitting on the stone. The moisture will make it easier to see imperfections in the stone. I cut my blocks with a hacksaw. It is labour intensive, but it does work. Ta for now, Kes From: irgenwer at ix.netcom.com (Kate was here) Newsgroups: rec.org.sca Subject: Re: Soapstone Casting (LONG) Date: Tue, 04 Feb 1997 11:27:14 GMT Organization: Quahaug Cannery >I'm fairly sure that a well dried/baked stone mould will handle >silver in small size castings. My question is how many repeat >casts one can get out of a stone mold with silver before the >mold starts to break down? We're talking a 1100 to 1200 >degree F temperature difference between the white metal alloys and >sterling. Has anyone out there tried it? -- al Thaalibi The massive talc I've used has cracked every time I've tried casting with metals whose melting points are above 1000 C. However, the molds I've made out of a very nice red-brown sericitic schist from Michigan have held up every time. I've cast silver, sterling, and various bronze alloys in this stuff very successfully. I've not broken any mold bases yet, but I've gone through a lot of keys on the two-piece molds I've made. I've only broken one key on the three piece molds I've made. The largest amount of silver I've done in a stone mold is one ounce. My bronze pieces are about the same size. I have no idea how many castings you can get with the higher melting temperature metals and alloys. I need to break a mold base first, and then I'll have an idea. Casting metals which melt above 1000 C require a very hot mold (not unlike investment molds)- which is not the case with pewter, where you can pour into a relatively cool mold. Actually, I would opine that heating the mold is much more imparative that for investment casting - especially for the first few castiing. Let me explain: "soapstones" are mostly phyllosilicates - minerals which grow in layer cake-like structures, with tightly bonded layers of SiO4, oxygens and OH, and a frosting between these layers of large cations like potassium. The large cations take up a lot of space between the Si/O/OH layers - so much so that there's room to stuff a lot water molecules into that gap. Phyllosilicates dehydrate when subjected to sufficient heats. I've knew this theoretically, but it never really sunk in until the first time I cast bronze in a stone mold - the mold blew up with a small cloud of steam, and molten bronze sprayed across the room. My guesstimate for mold temperature was approximately 500 C - obviously not hot enough. I took the pieces of the dead mold and examined the path of the hot metal through it. What I fould was an anhydrous silicate mineral coating the entire pathway. The anhydrous silicates are tough and melt at very high temperature - which means that the passage of the hot metal created a hard and resistant lining inside the mold. These days, I heat my molds to approximately 1000 C prior to pouring, and Ive not lost a mold since. Really cook your mold, and dress as if you know that the mold will self-destruct and spray metal. The dehydration of soapstone is a given, but if you really roast that mold, you can drive off a lot of the water trapped in the rock before it sees any hot metal. >djheydt at uclink.berkeley.edu (Dorothy J Heydt) wrote: >| Just keep in mind if you do, soapstone is solid talcum powder and >| can muck up your lungs if you allow it to get into them. Wear a >| filter mask while working it. I would say, conversely, that talcum powder is ground up talc, but here I'm probably picking nits ;-) What is sold as soapstone in the US is one of four different rocks: massive talc, massive sericite, talc +/- sericite schist and NON-abestoid serpentine. Art store people in general are not well-educated about the mineral content of the soapstones they sell. I've had people at one of the local art stores hand me serpentinite and tell me it was sericite. *sigh* You can work the soapstones WET. I've seen some people carve it in a large bowl of water. I personally prefer to carve it dampened with a wet cloth (which you also use to wipw off the wet clay-like scrapings as you work). If you don't work with rocks every day like I do, the exposure risk is extremely small, even if you carve it dry without a mask. The truth of the matter is that if you've not been fitted to a half or whole face respirator, then no mask you wear will give you assured protection. It's a basic tenet of respiration safety that unless you've been personally fitted to a respirator and have subsequently passed a fit test, then you must assume that the respirator leaks. Consider also that you make rock dust while dry carving - but unless you're working in a hood or a dust box, you're going to get rock dust in your clothes. That rock dust will follow you home, where you can breath it long after your carving is finished, and long after when you put your respirator away. The whole bit about a mask is kinda silly since it doesn't solve the problem of making dust - it might prevent you from inhaling some dust while you work, but it's not going to prevent you from taking some dust home with you when you're done rock carving. Not making dust in the first place is the preferred thing to do - and carving wet does this for you. The principle danger of working with silicates is the dust. It's worth mentioning that where I work, every rock saw, grinder, polisher and coring drill is set up to operate wet. david.razler at worldnet.att.net (David M. Razler) posted: >Adding to an excellent remark, "talcum" is another way of saying "contains >asbestos-like fibers" (please use cornstarch powder on the young ones. It is >not period, but it also makes for a better gravey when you cook them) I'd like my kid broiled, with potatoes on the side ;-) I'm afraid I must differ: talc is not one of the asbestos minerals. It breaks up into little platelets - it does not form fibers. No fibrous habit, no asbestos. Mind you, I'm defining asbestos as a certain set of minerals with fibrous habit and refractory character. This is a mineralogical definition - it is not the same as US-OSHA's definition, which is presumably based on occupational health criteria. What I call asbestos is actually much stricter than what OSHA calls asbestos. As a mineralogist, I'd define the two asbestos minerals as chrysotile serpentine and tremolite. They don't carve well if they carve at all. It would be like carving petrified fossilized linen. The dust hazard is real, regardless of the fact that the soapstones are non-fibrous. You won't get asbestosis from them, but you can get silicosis and stomach cancer with prolonged use. (Back before California turned into a rice growing area, rice was shipped by boat from asia. Many housewives in China Town in San Francisco would buy the rice and take it home. There they would wash it, and then feed it to their families. It was a mystery at the time as to why women from China Town had a much higher rate of stomach cancer with respect to the rest of the city, Then someone discovered talc in the rice bags. In order to ship the rice, the folks on the other side of the Pacific would throw in a handfull of powdered talc as a dehydrating agent. Since china town housewives were the only people to handle the unwashed rice, they got all the talc exposure. Asbetos, by the way, is defined by the US gov't to be any rock fiber with specific dimemsions (which I don't remember off the top of my head). The gov't doesn't use the mineralogical definition at all. The definition is soley based on size. IMHO, this is really stupid. An USGS employee showed almost 20 years ago that the asbetos which caused most cases of asbestosis was the tremolite variety. In addition, most of the non-mining asbestosis cases were from shipyards! Alternatively, I have never heard of any artists who died of silicosis from carving soapstone (if anyone does know of such a case, please correct! me ;) ttfn, Twcs From: j_mohler at wmc34b.wmc.edu (Jason) Newsgroups: rec.org.sca Subject: Re: medieval candles--?? Date: 6 Feb 1997 06:50:50 GMT Organization: Western Montana College, Dillon MT markh at risc.sps.mot.com (Mark S. Harris) writes: >I'm afraid he is not that far off. I guess it depends upon the vender. >I'm currently paying $0.50 or $1.00 per pound for the lowest of three >grades of soapstone here in Austin from the only Lapidary/rock shop >that has this stone in Austin, TX. And the last chunk I got had a lot >more oclusions and large particles than the stuff I got previously. > >Now where did you say this talc mine was? :-) Ten miles south of Dillon, MT. But if thats too far, theres also one in Three Forks, MT. :) Another idea might be ardulite(sp?). Its a sedimentary rock that is as easy to work with as soapstone. Around here it was used alot it ceremonial pipes. Its basically a clay, so it hardens when heated. The only thing is, I'm not sure how hard it is to get in the rest of the world, as (I think) it requires the presence of glacial lakes (any geologists/ minerologist help me on this?), which were plentiful in the northern Rockies, but a little lacking in Texas. Erik Blackwood ======================================================================= Jason Mohler "Could you please continue the j_mohler at wmc34b.wmc.edu petty bickering? I find it most http://www.geocities.com/Athens/4162/ intriguing." -Data From: irgenwer at ix.netcom.COM (Irgenwer Schuld) Newsgroups: rec.org.sca Subject: Soapstone Casting (WAY-LONG!!!) Date: 6 Feb 1997 02:32:15 -0500 >Greetings unto Twcs! >>Long time no hear from! I wasn't sure you were still frequenting the >Rialto. Got a well used soapbox around here, somewhere. Hi Stefan: This is the first time in a long while that I've had a little time to spare for lurking on the bridge. I guarentee that I'll be gone again for several months in just a few weeks. I'm on the home stretch for finishing my dissertation research, and it manages to eat up time very effectively! I'm also spending most of my time "allowance" for SCA activities on running the local fighter practice (in pursuit of my life-long ambition to become a stickjock!) I'm crossposting this to the rialto, since you brought up a question that more than one person may be interested in. Here goes: >This is the first time I've heard of carving saopstone wet. No one >suggested it here in previous discussions. In fact, some cautioned >against getting the stone wet, because the water wood boil off and >crack the stone similar to what you describe, even at pewter >temperatures. >I wonder if I could bake my mold in the oven after >carving it wet to dry it out? Perhaps nearer the boiling point of >water than the 500 degrees of the pewter? You basically have the right idea! I bake out my molds, first to drive off the residual non-stoichiometric water from carving it wet, and then to get it up to a temperature where I no loinger worry about any sudden dehydration reactions from the hydrous silcates present in modern soapstones. Well - hit me over the head with a wet noodle! Shame on me for not be sufficiently detailed. I watch the sculpture class in the room next door to where I do most of my casting - and they're all carving their soapstone under water in bowls and tubes, or with wetting it down with a wet towel. I'm under the impression from talking to the sculpture types, that this is becoming more and more common as artists get better educated regarding the materials they use. But with regards to carving your mold wet and then using it for casting, I need to get the noodle squad over to do their thing to me, for I now realize that I assumed everyone knew about how to properly bake a rock and why! I mean - just think about this for a second - here I am, sitting around and assuming that, of course, people bake their own rocks every day, all the time! Why, I think nothing of popping a rock into the furnace and cranking up the heat! YOU THINK I'M KIDDING?!?!?!?!?!?!? I'm not! But let me explain: I torture rocks for a living. I'm a professional mineral nerd. At this point, I probably have rocks in my head, as well as in my lab, my office, my truck, my closet, my bookcase (well, the nice-looking ones...). I don't think anything of just popping a rock into the oven, if that's the appropriate thing to do! So let me tell you in greater detail about how to bake a rock. First, don't do it with massive talc. There's a really lovely pale green massive talc currently on the market in the States and Canada that I see a lot of SCA folks east of the Rockies using for their pewter casting. But it has really serious problems with cracking while being worked. If you put massive talc in the oven, it's going to break! That's the nature of the mineral. If you want to use a "soapstone" (please see my previous post for the definition of this), use one of the schists on the market. A phyllosilicate-rich schist that's nice enough to be used as a soapstone has enough other stuff in it to keep it together while you abuse it. The lovely brown-red schist from Michigan is a real winner in this regard (give me a few days and I'll probably be able to hunt down the quarry name); there's also a delightfull sillimanite schist from the Ruby Mnts in Nevada that would do well for the casting application too. The talc schist from south of Mariposa in the south Sierra Nevada doesn't work (I tried) - it's not fine grained enough. So the first thing you need to do is pick the right rock to bake. Use a schist and not a one-mineral "soapstone" like sericite or massive talc. The second thing to do is carve it. Now, regardless of the actual identity of the rock you're using, if it cracks while you're carving it, it'll crack in the oven too. Rock that will crack with just little abuse will not last through high temperature casting. Now let's assume the mold is carved. For the sake of discussion, I'll use a three piece mold as an exavple. For pewter casting, the period practice (and current state of the art in SCA nations east of the Rockies) was to pour lead pins through the mold pieces to keep it aligned while pouring the pewter. If you're aren't familiar with this, there are some really helpful pewter-mavins who have properly constructed period molds and cast with them in the shopping district at Pennsic. One of them (a laurel from Ealdemere, I believe) has a very nice pamphlet with drawings and such - I'd go and check it out there, since you're much closer to Pennsic than I! Anyway, about pins: you'll need them. Melted bronze is too damn hot to pour without pins. (If it hadn't been for the pins I had put in my very first stone mold - the one that blew up from explosive dehy- dration of hydrous silicate minerals - I and my casting buddy may have ended up injured badly instead of merely embarrassed.) Now, I've not come up with anything elegant, like the lead pins in a pewter mold, but my current solution works well enough for me. I use bronze machine screws and fittings - marine hardware quality bronze, in fact. Why? Well, first, pouring bronze in a mold held together with bronze isn't going to melt the screws and nuts. And marine bronze can tolerate thermal expansion and contraction a lot better than most steel hardware. Last, I lifted my marine bronze machine screws, washers and nuts off my Dad's hoard of boat hardware so it didn't cost me anything. The bronze screws work well with melted silver too (I've poured silver twice now into one of my stone molds) To put them into the mold, I drilled with my low-speed dremel a hole just slightly smaller than the diameter of the screw-threads. Then I carefully hand=threaded the screws into the rock. I like a four screw arrangement best. Two screws through the key pieces, and a screw apiece through each key piece into the base. I do attach a nut to each threaded screw - the thought of an uncontained steam-and-hot-metal explosion while casting in a new mold is not a happy one. Actually bolting the fool thing together will keep any inadvertant explosion contained mostly within the mold itself. For metals above 1000 C, I'm not going to trust just pins. A burn from pouring pewter can be really really nasty - but a burn from melted bronze could ruin the rest of your life. Bolt the mold together. Now, after actually bolting the mold together, I retract the screws just a little bit, so there's a small air gap between the key pieces and the base. With all the hardware attached, and with small airgaps between pieces, I put my new mold into my home oven, at 200 F (note the temperature scale change here! It's important) overnight. If it lives, I crank up the temperature to 300 F the next night, and then to 400 F. If it lives (the massive talc dies before I ever get it out of the house, the schist survives), then I take it into the craft center on campus and put it in one of the casting kilns - to bake at 500 C (temp scale just changed back to celsius!) overnight or until I'm ready to cast - whichever is longer. When I'm ready to cast, that morning I will turn up the heat so the mold will be approx 1000 C when I have my metal melted and ready to pour. I'm estimating the 1000 C based on the color of the fire bricks on the inside of the kiln I like best at the craft center. (After you play with melting rocks and metals, you get a feel for temp in a furnace based on color, instead of having to dig out the thermocouple and poking it through the hole on top of the furnace) This is my current procedure. It might be overkill, but the exploding dehydrating schist made a deep impression on me the first and only time I had a mold explode on me. And any phyllosilcate that's been cooked a while at 1000 C is going to suffer surface dehydration reactions and metamorphose into its anhydrous pyroxene equivalent (in general - any rockknockers who want to pit nicks, can do through email...). And the way to get any rock hot (not just a phyllosilicate-rich one) is to do it gradually. Baking a rock too fast is like microwaving cold out-of-a-can raviolli on high: it go BOOM and make a mess! So, to sum up in just a few words: don't use massive talc, bring your mold up to temperature in steps gradually, and make sure your mold achieves 1000 C before casting. And if you're not wearing a foundry mask, hood, sleeves, mitts and attached apron (and equiv on your legs and feet), you're going to get hurt. This is real pyrometallugy here; dress appropriately. Paranoia is a good thing to have around the melted "first-row" metals. Oh, and one last thing: this isn't investment casting - so don't throw the mold into a bucket of water to cool it down. Do that and it will explode if it's still hot. I've seen rocks explode from thermal stress - it's not a pretty sight, especially when you've seen the injuries that people can get from flying hot-rock shrapnel. What did they do in period? (I can hear someone ask!) Well, thus far I've been able to document repeat-use molds for high-temp casting made out of fired-clay (one mold with many pieces!, for casting multiple bronze buckles at one shot), sericitic schist for silver jewellry pieces, calcareous sandstone (again for bronze) and fine-grained limestone (bronze). There. That's all you're going to get out of me this evening! And now it's back to procrastinating cleaning my kitchen... ttfn, Twcs From: james koch <alchem at en.com> Newsgroups: rec.org.sca Subject: Re: Brass Works Date: Sat, 03 May 1997 17:36:51 -0400 Organization: alchem inc Tiernan001 wrote: > I was looking for some help with some Casting and Etching that I need to > do for some decoration of my armor. I am especially interested in peroid > casting ( i.e. Lost Wax Casting and the like) and etching in general. I > am fairly familiar with Lost wax casting up until the point of what one > does with the wax and the Silica sand to make a mold. I'm not to familiar > with the actual melting of the Brass (i.e what tempratures, equipment for > safe casting, ect...) As far as Etching is concerned, I have etched Zinc > plate (for a Printmaking class) before, and was more interested in a > possible source for supplies (I have no clue as to where to buy acid, and > I forgot what chemical(s) the resistor was). I am probably biting off way > more than I can chew, but..... OH WELL! > > Tiernan Diego of the Waters > E-Mail at : Tiernan001 at aol.com Mr. Diego, There are a number of materials from which you can make molds. You can carve and cast directly in soapstone, refractory brick (the stuff used to line kilns), or graphite. You can make an original and press it into foundry sand (fine sand with powdered dry clay added), dental plaster, or clay. The plaster and clay must be thoroughly fired to remove all traces of water prior to pouring the metal!!! Otherwise the mold will explode spewing molten brass. Commercial crucibles are available from various sources. In a pinch you can melt brass in a piece of black iron pipe screwed into a cast iron pipe cap. An enamelling or ceramic kiln will provide sufficient heat if you plug the vent holes. For safety's sake buy a bag of play sand and nail 2 x 2s to a piece of plywood to make a sandbox. Molten metal can be poured on sand. Do not pour or spill molten brass on concrete since the cement contains water of hydration!!! More flying molten brass. Sulfuric and hydrochloric acids can be purchased by the quart or gallon at most hardware stores. These are sold as Organic Digestor in the plumbing section and as Muriatic Acid in the paint section. Mix the Sulfuric Acid with Sodium Nitrate which is sold as Nitrate Of Soda Fertilizer in the gardening section. From this mixture you can distill off Nitric Acid. The Nitric Acid can be used to compound Aqua Regia for etching. Also, before I forget, always melt brass in a well ventilated area. I used to melt indoors and would come down with Zinc fume fever afterwards. When brass melts the Zinc boils off and ignites producing a blue white flame over the crucible. The resulting Zinc Oxide smoke when breathed forms soluble Zinc Hydroxide in the lungs. This is absorbed into the bloodstream where it disrupts your body's temperature control and you go from the violent shaking chills to the sweats and back again for several hours. Fortunately Zinc occurs in the body naturally and the kidneys rapidly excrete the excess. Good luck and have fun! Gladius From: Corbie <corbie at no-spam.radix.net> Newsgroups: rec.org.sca Subject: Re: Brass Works Date: Sun, 04 May 1997 19:04:52 -0700 > tiernan001 at aol.com (Tiernan001) wrote: > > I was looking for some help with some Casting and Etching that I need to > > do for some decoration of my armor. I am especially interested in peroid > > casting ( i.e. Lost Wax Casting and the like) and etching in general. (snip) > > Tiernan Diego of the Waters > > E-Mail at : Tiernan001 at aol.com My husband and I have both done bronze