soapstone-msg – 2/2/10
Use of soapstone in period. Modern sources. Carving suggestions and warnings.
NOTE: See also these files: casting-msg, plaster-msg, sculpture-msg, Relief-Carvng-art, frescoes-msg, ivory-msg, ivory-bib, pewter-msg, tiles-art.
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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
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Date: Wed, 5 Feb 1997 22:11:37 -0800
From: irgenwer at ix.netcom.com (Irgenwer Schuld)
Subject: Soapstone Casting (WAY-LONG!!!)
To: "Mark Harris" <mark_harris at quickmail>
>Greetings unto Twcs!
>>Long time no hear from! I wasn't sure you were still frequenting the
>Rialto. Got a well used saopbox 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
Date: Thu, 16 Oct 1997 18:38:56 -0500
From: theodelinda at webtv.net (linda webb)
To: sca-arts at raven.cc.ukans.edu
Subject: Re: Viking scrolls--stonecarving
Soapstone is _very_ Scandinavian, and there's a reason why it's called
soapstone--it's almost that easy to carve. Quite a few of the big
artists' suppliers, like Dick Blick, sell it in small pieces for
sculpting. While it was mostly used in period for cooking vessels, why
not use it for a "personal" runestone--like an AoA scroll
Date: Mon, 20 Oct 1997 16:15:18 -0500
From: rockwallshire at webtv.net (Shared Account)
To: sca-arts at raven.cc.ukans.edu
Subject: Re: Viking scrolls--stonecarving
Re Soapstone:
Try Nasco. They sell soapstone for reasonable prices; in the 1997
catalogue, they have it listed in ranges of $1.55 for a 1-2 lb piece
through $10.20 for a 9-11 lb piece. They also carry a fun little kit
called "Rocks in a Box" for about $25; this kit contains a small stone
of amulet size, a larger stone about the size of your hand (or, at
least, the hand of a 5'8" woman), and tools needed for carving.
1-800-558-9595. I use the Ft. Atkinson warehouse (especially since,
until about a month ago, I lived within walking distance of it), but I
think you'll want the Modesto, CA warehouse. They also have a web site:
htttp://www.nascofa.com
email: info at nascofa.com
I hope this is helpful to you.
I am, your servant, Merouda, writing through the Rockwall account.
Date: Tue, 21 Oct 1997 00:38:57 -0400 (EDT)
From: DianaFiona at aol.com
To: sca-arts at raven.cc.ukans.edu
Subject: Re: Viking scrolls--stonecarving
<< >
> Soapstone is _very_ Scandinavian, and there's a reason why it's called
> soapstone--it's almost that easy to carve. <...>
Yes, but my understanding from all I have heard about it is that it is
quite expensive. Not that my project recipient isn't worth it:), but
working in expensive new materials on a wild project like this is, would
be foolish.
Does anyone have info on fairly inexpensive soapstone? We are in
Greeley, Colorado if that makes shipping or distance an issue.
Thank you,
Lughbec
>>
Oh, the *soapstone* isn't that bad---the shipping on the other
hand......:-( Anyway the best place I know of to get it is Steatite of
Southern Oregon--not bad for you in Colorado. Unfortunately I'm in Tennessee!
You can contact them at:
(503) 479-3646 (Phone or fax)
2891 Elk Ln
Grants pass, Oregon 97527
Hope that helps.........
Ldy Diana Fiona O'Shera
Date: Thu, 6 Nov 1997 19:28:17 -0500
From: woodchucker at tbscc.com (Charles S. Myers)
To: <sca-arts at raven.cc.ukans.edu>
Subject: Re: soapstone sources?
I sculpt and have numerous art supply scources Dick Blick at 1-800-828-4548
Artfully Lidia De Algarve----------
Date: Wed, 17 Mar 1999 18:18:26 -0500
From: rmhowe <magnusm at ncsu.edu>
To: sca-arts at raven.cc.ukans.edu
Subject: Re: Soapstone
styrbjorn at juno.com wrote:
> Does anyone know where I can get relatively large chunks of soapstone? I
> want to carve some cooking vessels like the ones the Vikings used.
> Soapstone is supposed to be a natural non-stick surface. Wow, easy clean
> up at wars....
>
> Styrbjorn Ulfhamr
http://www.geocities.com/SoHo/Gallery/4821/CarvingPrimer/carvspsrcs.html
Magnus
Subject: Soapstone and Asebestos
Date: Sat, 01 Jan 2000 13:59:31 -0800
From: Pat Reed <preed at sos.net>
To: stefan at texas.net
Stefan:
I sent this to a couple other folks, who asked me to send it to you for
inclusion in the Florigilleum, if you think it would be valuable. You
have my permission if you choose to use it.
Patricia of Leicester
It seems I've confused everybody about soapstone and asbestos, so here's
a little more coherent information:
Soapstone is the massive form of talc, which is a metamorphic rock. If
it was a volcanic rock originally, it may have chlorite, actinolite,
epidote, and albite with it, and be converted to a greenschist.
"Granites" with a larger percentage of heavy minerals (usually dark)
will go to serpentines (a group of three minerals). If it was a
sedimentary rock, like a dirty sandstone, it will have chlorite,
muscovite (white mica), albite, and quartz with it, and form slates,
phyllites, and fine-grained schists. If it was a rock with calcium,
like a dolomite or limestone, it will have calcite, dolomite, tremolite,
phlogopite (brown mica), epidote, and quartz. Clean quartz sandstone
become quartzite, and dolomite or limestone goes to marble. The
"prolith" or original rock is put under about 2 to 8 kilobars of
pressure (about 5 to 20 kilometers depth of burial) and heated to
between 300 and 400 degrees Celcius. This can be the result of
subduction, regional metamorphism, or the emplacement of a granitic
"pluton". This is referred to as the "greenschist facies" of
metamorphism. These rocks are completely recrystallized, and usually
are well foliated. They are very, very common.
I've mentioned all of these minerals to show that "talc" is part of a
spectrum of minerals that occur together. The minerals found in an
outcrop or quarry can change over a distance of a few meters. The word
"asbestos" actually refers to the form the mineral takes naturally, like
the round "equant" shape of a natural garnet. Several types of minerals
have this characteristic hairlike, flexible form. There are five
minerals that are mined for "asbestos" used in commercial applications:
chrysotile (one of the serpentine minerals), crocidolite (an asbestos
form of riebeckite), anthophyllite (found with talc and serpentine),
actinolite-tremolite (which are closely associated with talc), and
cummingtonite-grunerite (which shows up at a higher temperature of
metamorphism than talc). The fine fibers of asbestos can be inhaled, or
get stuck in skin. The irritation this causes can lead to a variety of
diseases. The amount of exposure is the critical factor in risk
assessment. A "sanding" dust mask and goggles are absolutely necessary
when working soapstone.
So how do you know if the soapstone you're working on has any of these
asbestos minerals? You can't, because the color and hardness are very
similar in these minerals. If a you are buying from a quarry, ask them
about the mineralogy. The State's Natural Resources department will
often have that information too.
Anders, you may have had a bit of pyrophyllite in that mold that
exploded. It's associated with talc, but has more aluminum than iron.
It's white, apple-green, gray, or yellow, and softer than talc. The
name "pyro" refers to "fire" and "phyllon" means "leaf" because it falls
apart like a stack of leaves when heated. It looks more like white mica
than talc, but even my Mineralogy books say it's difficult to tell them
apart.
Notable occurrences in Norway: at Altemark, near Mo i Rana (close to a
fjord, so accessible by longship), at Framfjord in the Sognefjord area,
Otta and Kvam in Gudbrandsdalen southeast of Alesun (this is structural
quality stone),
and at Kodal (90 km south-southwest of Oslo). It also was quarried by
the Vikings on the Shetland Islands according to one reference. In
Sweden, the noted deposits are in the Garpenberg Odal field, southwest
of the Kristineberg area, and at Ravlidmgran. My email program doesn't
include Scandinavian notation, Anders, so I had to approximate the place
names.
Pat
(Geologist)
Date: Thu, 17 Feb 2000 13:00:19 -0500
From: rmhowe <magnusm at ncsu.edu>
To: sca-arts at raven.cc.ukans.edu,
"- Metalcasting at onelist.com" <Metalcasting at onelist.com>
Subject: Re: Soapstone
> Melanie Wilson wrote:
> Anyone had experience turning this ?
>
> Mel
It's occasionally written up in some of the woodturning magazines
I read. American Woodturner or the (British) Woodturning.
Generally, it has to have no cracks and be turned at a very slow
speed. Most of the turnings I've seen have very small size to them.
I can't remember for certain but I think some folks use cyanoacrylate
glues (superglues) to stabilize any potential cracks. This is common
in some brittle materials. How well it might work in soapstone I don't
know and I haven't tried it. It may or may not work. My suspicion
is also that superglue may come apart with heat so I shouldn't cast
with something held together with it.
In period though most lathes wouldn't have had the speed that modern
lathes do and that wouldn't have been such a hazard (having a piece
fly apart at you on the lathe). Pole lathes and less-than-great wheel
lathes just don't attain that type of speed.
As far as molds go for metalwork, the Romans used stone molds to
cast what is presumed pewter plates into. I think I have recently
also seen a piece of a stone medieval plate mold in a book. I
have the Roman article (which was parts of five molds). I may have
the other but I got so many archaeological books in recently I haven't
had time to read them yet.
Blagg, Thomas: The Roman Pewter Moulds from Silchester,
Antiq. Journ. 57, 1977 pp. 270-6. May, or may not, have been lathe
turned. Conjectural. Also considered to have been scraped possibly
from a center pivot.
The Romans were definitely using lathes to finish some of their
metal cast objects. See Strong's Roman Crafts. This was common, and still
is, to finish cast pewter objects, particularly round ones like tankards
and jugs.
Of course you are aware of the danger for silicosis or asbestosis
associated with turning/working such stuff. Depends on the variety.
Some varieties have it in greater amounts than others, some have
practically no asbestos. It can get on your clothes and be transmitted
by washing clothes to other folks in your family. Just so you know
it's a possibility. You're going to liberate a whole lot more of it
turning and scraping the stone, and the rotation of the lathe sets up
a natural draft to throw it around.
My understanding from someone on the SCA-Arts list is that slate
tends to break up into tiny sharp pieces and is also hazardous to inhale.
It was also used in places like the Netherlands to cast low temperature
metals in. See Heilig et Profaan and the thousand pewter tokens it
depicts. It also depicts the moldmaking process. They cast pins in place
by using a three piece mold. The two molds that matched up on one side
of the larger one had a bent pin and 'keeper' stud in their mating edges.
This is a Dutch book and may still be available from Oxbow for about
$90. Why slate? It's what they had. Soapstone doesn't occur
everywhere.
For carving this sort of stuff:
I suggest using something like a bathroom fan with outlet hose
set behind the mold or soapstone you are working to downdraft it away
from you and to vent it directly outside. Bathroom vent fans can be
had quite cheaply here in the U.S. (about $15). The very same kind
you would mount in a ceiling or wall but with an attachment hose.
A respirator wouldn't hurt either. This is not going to be sufficient
for a modern lathe. I'm not sure what would be and I wouldn't particularly
want to empty out the dust bag from a shop vac or vacuum system that
might contain asbestos. I've been around that stuff, I don't like it.
Lest anyone suspect I'm a lightweight in the shop area, I spent well over
twenty years making thousands of objects in various trades and studied
Industrial Arts in university for five years. I've used most types of
machinery (and fixed them).
Magnus
Date: Thu, 17 Feb 2000 14:05:00 EST
From: <DianaFiona at aol.com>
To: Metalcasting at onelist.com, sca-arts at raven.cc.ukans.edu, Dunstan at onelist.com
Subject: Re: [Metalcasting] Re: Soapstone
In a message dated 2/17/00 1:05:07 PM Eastern Standard Time, magnusm at ncsu.edu
writes:
<<
Generally, it has to have no cracks and be turned at a very slow
speed. Most of the turnings I've seen have very small size to them.
I can't remember for certain but I think some folks use cyanoacrylate
glues (superglues) to stabilize any potential cracks. This is common
in some brittle materials. How well it might work in soapstone I don't
know and I haven't tried it. It may or may not work. My suspicion
is also that superglue may come apart with heat so I shouldn't cast
with something held together with it.
>>
I haven't used superglue yet, but epoxy works just fine to repair cracked
or broken soapstone. Once filed and sanded it's not usually noticeable and
holds very well. I have heard either it or superglue recommended as repairs
for broken molds, with whoever suggested it saying that the glue in question
could withstand the temps associated with pewter casting. Unfortunately, I'm
blanking on exactly which glue was being discussed........... I haven't had
occasion to try it since I heard this tidbit, either, so I can't judge from
experience, there.
Ldy Diana
Date: Fri, 18 Feb 2000 00:51:42 -0800
From: Therasia <no1home at encompass.net>
To: sca-arts at raven.cc.ukans.edu
Subject: Re: Soapstone
> > Melanie Wilson wrote:
> > Anyone had experiance turning this ?
Yes, I've sawn, cut, whacked, ground, polished, turned, shaped,
pulverized, dissolved, melted, and even sublimed just about
every rock and mineral in existance - or at least it feels that
way. Rock lathes (yes, they do exist) differ from wood lathes in
a number of ways. First, they are designed to deliver a constant
stream of water to the working surface - in this respect they're
more like industrial lathes (which can also wet a surface).
They tend to have non-tradition means to mount the rock on the
spindle (I'm not sure that's the right name). The larger lathes
have funky clamps, instead of chucks, to hold the rock in place,
and the rocks have to be sawn beforehand in order to get them
into the clamp arrangement. I'm assuming here that the usual
sort of itty bitty jewelry lathe is not an option for making
your bowls.
A local lapidary club might have a rock lathe available. If you
don't work in a place whose business is rocks, asking around in
the lapidary community is probably the way I'd recommend to get
help in turning a rock.
rmhowe wrote:
> My suspicion is also that superglue may come apart with heat
> so I shouldn't cast with something held together with it.
I don't think I'd ever attempt the glue tactic if I was casting
at precious metal temps. Even the most refractory rock glues
fall apart by 500 C. I don't know what the temperature of
combustion is for superglue, but I'm willing to bet it'd burn
off well before 500 C.
I strongly recommend baking your molds before using them for two
reasons. In general, baking your molds will find the ones who
would have cracked from thermal shock and expansion in the middle
of a pour. It's much safer for them to crack inside a furnace away
from people. The other reason to bake your molds is to drive off
loosely bonded water. If present, any excess water in the mold
will flash to steam the first time hot metal comes its way,
possibly causing the mold to explode, complete with droplets of
melted metal flying everywhere.
I take my molds up to at least 800 C in steps. Molds for pewter
casting need never see a furnace again. Molds for bronze and
precious metal casting should be heated everytime before casting,
otherwise the reaction between the cold air in the mold with the
hot metal can be a little too exciting.
> In period though most lathes wouldn't have had the speed that modern
> lathes do and that wouldn't have been such a hazard (having a piece
> fly apart at you on the lathe). Pole lathes and less-than-great wheel
> lathes just don't attain that type of speed.
It boggles the mind that all those beautiful antique jade carvings
were done on pole lathes.
> I think I have recently
> also seen a piece of a stone medieval plate mold in a book.
Is it the one in _Dress Accessories_ (part of the Museum
of London's series on the excavation of medieval garbage dumps)?
That one was a fired clay mold for making multiple belt buckles,
if my memory doesn't fail me.
> Of course you are aware of the danger for silicosis or asbestosis
> associated with turning/working such stuff. Depends on the variety.
> Some varieties have it in greater amounts than others, some have
You know, this comes up about once a year, and here I am babbling
away again about it. One of these days, I'm going to get around to
making a web site with all this stuff, so in the future I can just
point to the web site instead of typing typing typing...
Let me try to change your perspective about this topic. I'd advise
not worrying about asbestosis and silicosis specifically. They are
only a small part of the overall rock dust hazard. The safety guy for
my lab boiled it down for me rather succinctly a while back, and
it goes like this:
ALL ROCK DUSTS ARE BAD.
And if you think about it, that's exactly how it is. (I keep on
wondering why I didn't think of that - I guess it was so obvious
that I never saw it right under my nose.) Of course some rock dusts
are worse than others, but all of them are bad news. About 5 yrs
ago, the Mineral Society of America put out a volume in their
Reviews of Mineralogy series entirely devoted to this subject.
> practically no asbestos. It can get on your clothes and be transmitted
> by washing clothes to other folks in your family. Just so you know
> it's a possibility. You're going to liberate a whole lot more of it
> turning and scraping the stone, and the rotation of the lathe sets up
> a natural draft to throw it around.
It doesn't have to be that way. Rocks should never be cut on
or by machinery in a dry state. The working surface should be wet.
A directed stream of water not only prevents rock dust, but it also
sends any dust-sized debris down the drain. Wet rocks are your friends,
especially if your soapstone is a serpentinite or rich in talc. Rock
dusts are completely avoidable. The best way to deal with a rock dust
hazard is not to make the dust in the first place. :)
Some soapstones are worse then others. This a list of rocks sold as
soapstone, sorted from worst to better in terms of dust hazard:
serpentinite
massive talc (this includes steatite)
tremolitic talc schists
sericitic talc schists
micaceous shale
> My understanding from someone on the SCA-Arts list is that slate
> tends to break up into tiny sharp pieces and is also hazardous to
> inhale.
Well, after all, all rock dusts are bad... ;-)
Seriously though, even the non-carcenogenic dusts can hurt you.
Carbonate dusts plus sweat equals mild chemical burns, for example.
And even the most benign rock particle can become the nucleation
site for pneumonia if inhaled and lodged in a lung.
>From Mel:
> Slate can be dangerous & I do wonder on the type for casting, I
> certainly wouldn't try with our local slate MUCH to big a risk of
> expolsion, too many fracture planes etc.
Yes, slate does break easily, planar fracture, exploding pyrite
concretions, and all that. It's good for roof tiles and formerly
for chalkboards, but as a casting mold??? Shale would be a much
better choice. Softer to carve and less likely to shatter into
paper-thin tabular spinters with an attitude.
And back to Magnus:
> For carving this sort of stuff:
> I suggest using something like a bathroom fan with outlet hose
> [much stuff on ventilation snipped]
> I wouldn't particularly want to empty out the dust bag from a shop
> vac or vacuum system that might contain asbestos.
Nor would I. Working wet though removes the need for ventilation,
which may not work as desired since a household fan is going to deliver
turbulant, and not laminar flow. I rather dislike the thought of many
two-micron fibers eddying off in oblique directions in turbulant flow.
It's probably completely impractical, but I now have this thought
stuck in my mind of Mel in the backyard, with a big pole lathe and
a lawn sprinkler to keep the rock wet...
> I've been around that stuff, I don't like it.
There's no denying that asbestosis is a nasty way to die. But there
are times when I think the perceived hazard is way out of proportion
to the actual danger. But that's a different topic for a different day
on a different mailing list than this one.
> Lest anyone suspect I'm a lightweight [snip...]
You? A lightweight? Magnus, I don't think anyone with common sense
would think that of you. :)
ttfn, Therasia
To: sca-cooks at ansteorra.org
Date: Sat, 29 Sep 2001 21:19:51 -0400
Subject: Re: [Sca-cooks] Soapstone, was: Marble slabs
From: Elizabeth A Heckert <spynnere at juno.com>
If you do a search for New World Soapstone, they have a website for
their soapstone. They are a soaptone quarry in Schuyler, VA, and their
main production is for counters and floors. We went to get tailings (I
needed loomweights) and talked to a gentleman who was making bowls out of
the stone.
Many warp-weighted looms' weights were actually broken soapstone pots.
Soapstone was a main export from Scandinavia in the Viking era
specifically for cook pots and lamps. Unlike the earthenware or clay
pots, the soapstone can come in contact with the fire.
When I went to pay for my bag o'rocks, I saw part of a price list.
Almost $30.00/square foot for counter top. The main building there
(dates from the Civil War era) was made of soapstone in the manner of the
stone fences that don't use mortar. Very cool!
Elizabeth
Date: Sun, 30 Sep 2001 23:43:08 -0500
To: sca-cooks at ansteorra.org
From: Nicolas Steenhout <vavroom at bmee.net>
Subject: Re: Re: [Sca-cooks] Marble slabs
>Where do you get your carving stone? I am having a hard time finding soapstone
>of the right softness. what I find will do, but I have hard time getting
>deatil do to crystal sizes and hardness . . . . though my molds are nigh
>inviceable :o)
I'm not Stefan, but here's where I've ordered soap stone from a couple
times.
http://www.montoyasculpture.com/Merchant2/merchant.mv?Screen=CTGY&;Store_Code=MSS&Category_Code=CSS
If that doesn't come up properly, try http://www.montoyasculpture.com
and weave your way to the soap stone section.
Muiredach mac Loloig
Rokkehealden Shire
From: val_org at hotmail.com (Gunnora Hallakarva)
Newsgroups: rec.org.sca
Subject: Re: Soapstone?
Date: 31 Dec 2001 06:09:33 -0800
>> Ralph Lindberg & Ellen Winnie wrote:
>> I suggest that you buy it from a commercial source, possibly
>> soapstone.com The reason is many soapstone deposits have asbestos. You
>> don't really want to carve stone and free asbestos fibers.
ruhl at latakia.dyndns.org (Robert A. Uhl) wrote:
> Asbestos really isn't that nasty unless you're in the asbestos
> business. Or carving it all the time. It wouldn't hurt to make a few
> carvings, but if you're going to make a habit of it I'd recommend
> against.
Soapstone typically consists of 50 to 80 percent talc (Mg3Si4O10(OH)2)
mixed with chlorite, serpentine, pyrite, quartz, calcite, magnesite,
and dolomite. Some talc *may* contain asbestos -- generally not
soapstone, nor the talc that's in almost every consumer product you
use -- but the big problem in soapstone is the talc.
Talc is carcinogenic (never mind that it's used in all cosmetics and a
staggering number of consumer products). Chronic exposure to talc dust
may result in benign or malignant pheochromocytomas of the adrenal
gland, alveolar/bronchiolar adenomas, and carcinomas of the lung. In
layman's terms, that's "lung cancer".
Talc is also a phyllosilicate, which means that breathing the dust
also puts you at risk for silicosis, a type of lung disease related to
black-lung, asbestosis, etc. Silicosis is a disabling, nonreversible
and sometimes fatal lung disease caused by overexposure to respirable
crystalline silica, such as soapstone dust. There is no cure for the
disease.
The National Institute for Occupational Safety and Health (CDC/NIOSH)
defines the REL (Recommended Exposure Limit) for soapstone at 6 mg/m3
(total dust), 3 mg/m3 (respirable).
For the official study of talc that was done to determine these
standards, see:
Toxicology and Carcinogenesis Studies of Talc
http://ntp-server.niehs.nih.gov/htdocs/LT-studies/tr421.html
See also:
OSHA Soapstone Exposure Guidelines
http://www.osha-slc.gov/dts/chemicalsampling/data/CH_267400.html
http://www.osha-slc.gov/dts/chemicalsampling/data/CH_267395.html
ACGIH [1971]. Soapstone. In: Documentation of the threshold limit
values for substances in workroom air. 3rd ed. Cincinnati, OH:
American Conference of Governmental Industrial Hygienists, p. 232.
Miller JW, Sayers RR [1941]. The response of peritoneal tissue to
industrial dusts. Public Health Rep 56(1):264–272.
SO, What does all this mean? It means that you should probably work
your soapstone wet, to minimize dust, and also that you should wear a
good quality mist mask, provide good dust-control and ventilation,
etc. All the same recommendations made for carving antler apply with
soapstone, but even more so because of the cancer risk.
::GUNNORA::
From: Bill Schongar <bschonga at cisco.com>
Newsgroups: rec.org.sca
Subject: Re: Soapstone?
Date: Wed, 02 Jan 2002 09:26:50 -0500
Organization: Cisco Systems, Inc.
> Where can you buy decent sopastone for pewter mold carving?
Lee Valley/Veritas (www.leevalley.com). Besides being an excellent
source for woodworking tools at low prices, they have a suprising
variety of other stuff.. soapstone, one-piece spring scissors, book
reprints, etc.
They also have the advantage of being suprisingly cheap.
-Liam
(Who gets soapstone from Lee Valley all the time...)
Date: Sun, 12 Dec 2004 13:58:14 -0500
From: "Daniel Phelps" <phelpsd at gate.net>
Subject: Re: [Sca-cooks] Soap stone dishes & bowls - a question
To: "Cooks within the SCA" <sca-cooks at ansteorra.org>
Was written:
> During my afternoon shopping endevour to conquer the Evil Beast of Giftmas
> Descending, I discovered that our Oxfam World shop have some lovely
> soapstone dishes in stock.
>
> They're the perfect size to be used for drinking cups for my viking honey
> but I wasn't sure if soapstone could be used for that sort of use.
>
> Can anyone advise me on this? - does soapstone react badly to such things as
> mead or ale or ?
Soapstone previously was much valued because it is non-reactive, resistant
to high heat and easy to work. I work of the Florida Geological Survey and
our building, specifically built for the Survey back in the early 50's has,
in its older unrenovated portions still has soapstone sinks and countertops
that have been proof against chemical spills for years. That being said I
cannot say if the soapstone you have does not have an admixture of asbestos
fiber in it.
Daniel
Date: Sun, 12 Dec 2004 22:19:12 -0500
From: "Ruth Tannahill" <rtanhil at fast.net>
Subject: [Sca-cooks] soapstone
To: <sca-cooks at ansteorra.org>
Daniel Phelps wrote:
> Was written:
>> During my afternoon shopping endevour to conquer the Evil Beast of Giftmas
>> Descending, I discovered that our Oxfam World shop have some lovely
>> soapstone dishes in stock.
>>
>> They're the perfect size to be used for drinking cups for my viking honey
>> but I wasn't sure if soapstone could be used for that sort of use.
>>
>> Can anyone advise me on this? - does soapstone react badly to such things as
>> mead or ale or ?
>>
> Soapstone previously was much valued because it is non-reactive, resistant
> to high heat and easy to work. I work of the Florida Geological Survey and
> our building, specifically built for the Survey back in the early 50's has,
> in its older unrenovated portions still has soapstone sinks and countertops
> that have been proof against chemical spills for years. That being said I
> cannot say if the soapstone you have does not have an admixture of asbestos
> fiber in it.
>
> Daniel
Soapstone is, chemically speaking, really hard talc. It's magnesium
silicate. Acids will etch it. In other words, ale and mead are fine. Wine,
not really. It will certainly dull the finish, although any trace quantities
dissolved in the wine are unlikely to be harmful. Also, keep in mind that
anything carbonated contains carbonic acid. If left in the vessel long
enough, it will etch the finish. I would not use anything soapstone as a
storage vessel.
As to the presence of asbestos, I cannot attest. I suppose it's possible.
But please note that ingesting asbestos in trace quantities is no where near
as harmful as inhaling it. Before you lot give me holy heck for that, let me
quickly state that I would not recommend eating it, or eating out of
anything that could possibly contain it. I'm merely observing that it has a
less harmful effect on the digestive tract than it does on the lungs.
Asbestos is really only harmful when particulate. As long as it's trapped in
the matrix of the rock, it wouldn't get into the food even if it were there.
As long as you didn't put acidic foods or beverages into the vessel.
I would be more worried about the possibilities of heavy metals or trace
organics in the mixture.
Were the vessels listed as food safe? If so, they've been tested for harmful
agents and are safe to use. If they were not listed as food safe, I would
use discretion.
For example: Pier 1 sells wooden chargers that are not food safe. The reason
they are not food safe is that they have been finished with something that
is not food safe. I would go ahead and put bread, fruit, or cheese on one,
but I would not slurp up sauce off one.
If it were me, I would go ahead and use them for ale or mead. But not for
wine!
Berelinde
mundane chemist
Date: Sun, 15 Jan 2006 08:53:49 -0600
From: Robert Downie <rdownie at mts.net>
Subject: Re: [Sca-cooks] Soapstone (was RE: Bread machine revisited)
To: Cooks within the SCA <sca-cooks at ansteorra.org>
I get my soapstone locally (in Canada), convieniently cut into blocks
(which we then slice with a bandsaw), from Lee Valley - the mecca of
cool tools.
http://www.leevalley.com/wood/page.aspx?c=1&;p=32712&cat=1,250,43298
They do mail order too, and they have so much cool stuff
I've also seen it in larger art supply stores, but in HUGE irregular
chunks more suitable for making sculptures than small casts.
Faerisa
Date: Tue, 12 Jun 2007 17:43:29 -0500
From: "Terry Decker" <t.d.decker at worldnet.att.net>
Subject: Re: [Sca-cooks] Lemon syrup.
To: "Cooks within the SCA" <sca-cooks at lists.ansteorra.org>
Soapstone spreads heat evenly and well, so well that Tulikiva (I think
that's spelled right) uses it in wood fired stoves designed for heating
rooms. The big drawback is they, like ceramic tiles, can break easily.
Bear
> I've heard of soapstone griddles but have no experience in how
> well they actually work. Hoecakes got their name from being cooked
> on hoe blades or shovels.
>
> Gunthar
Date: Thu, 14 Jun 2007 22:04:21 -0400
From: "Daniel Phelps" <phelpsd at gate.net>
Subject: Re: [Sca-cooks] Lemon syrup.
To: "Cooks within the SCA" <sca-cooks at lists.ansteorra.org>
Was written:
<<< Soapstone spreads heat evenly and well, so well that Tulikiva (I think
that's spelled right) uses it in wood fired stoves designed for heating
rooms. The big drawback is they, like ceramic tiles, can break easily. >>>
My response:
Soapstone, also know as steatite, is talc, a magnesium silicate. It is used
for laboratory table tops and lab sinks as it is unattacked by acids. We
have a number of both in our building. I do recall reading that it was and
is traditionally used in wood stoves in Europe because of its heat retaining
qualities. It is rather soft. Pure talc can be scratched with a
finger nail.
Daniel
Date: Fri, 15 Jun 2007 14:54:51 -0500
From: "Terry Decker" <t.d.decker at worldnet.att.net>
Subject: [Sca-cooks] Soapstone Re: Lemon syrup.
To: "Cooks within the SCA" <sca-cooks at lists.ansteorra.org>
> Soapstone, also know as steatite, is talc, a magnesium silicate. It is used
> for laboratory table tops and lab sinks as it is unattacked by acids. We
> have a number of both in our building. I do recall reading that it was and
> is traditionally used in wood stoves in Europe because of its heat retaining
> qualities. It is rather soft. Pure talc can be scratched with a finger nail.
>
> Daniel
>
> mka
> Daniel C. Phelps, P.G.
> Florida Geological Survey
If I have the right of it, talc is hydrous magnesium silicate, which is
deposited by sedimentation or hydrothermal injection. Talc is also used to
describe the softest form of soapstone, a metamorphic rock consisting mainly
of magnesium silicate with varying amounts and kinds of chlorite. Talc has
a Moh's hardness of 1. Soapstone has a Moh's hardness varying between 1 and
3. Steatite is more commonly used to describe the harder varieties of
soapstone which are used as countertops and heat sinks.
Bear
Date: Fri, 15 Jun 2007 20:27:29 -0400
From: "Daniel Phelps" <phelpsd at gate.net>
Subject: Re: [Sca-cooks] Soapstone Re: Lemon syrup.
To: "Cooks within the SCA" <sca-cooks at lists.ansteorra.org>
Was written:
<<< If I have the right of it, talc is hydrous magnesium silicate, which is
deposited by sedimentation or hydrothermal injection. Talc is also used to
describe the softest form of soapstone, a metamorphic rock consisting mainly
of magnesium silicate with varying amounts and kinds of chlorite. Talc has
a Moh's hardness of 1. Soapstone has a Moh's hardness varying between 1 and
3. Steatite is more commonly used to describe the harder varieties of
soapstone which are used as countertops and heat sinks. >>>
Hmmm... I was quoting, in the main from a rather old dog eared copy of
Dana's Mineralogy. Per Dana, "...talc is a secondary mineral formed by the
alteration of magnesium silicates, such as olivine, pyroxenes, and
amphiboles, and may be found as pseudomorphs after these minerals.
Characteristically in low-grade metamorphic rocks, where, in massive form,
soapstone, it may make up nearly the entire rock mass. It may also occur as
a prominent constituent in the schistose rocks, as in talc schist.
In the United States many talc or soapstone quarries are located along the
line of the Appalachian Mountains from Vermont to Georgia. The major
producing states are California, North Carolina, Texas, and Georgia."
Talc is of course a mineral while soapstone is a rock. As such soapstone is
typically an admixture of several minerals with talc predominating. I can
try and provide old world locations if anyone is interested.
Daniel
Date: Sun, 17 Jun 2007 14:03:33 -0400
From: "Daniel Phelps" <phelpsd at gate.net>
Subject: Re: [Sca-cooks] Soap Stone
To: "Cooks within the SCA" <sca-cooks at lists.ansteorra.org>
Checked one of my European sources "The Illustrated Encyclopedia of
Minerals and Rocks" by Dr. Jifi Kourfimsky. Per that:
"Talc received its name from the Arabic language. The name of the compact
to massive variety--steatite, is of Greek origin. It was a familiar
mineral long ago. The so-called potstone (mixture of talc and chlorites)
was chiefly used in the past for the manufacture of pots; the attractive
coloured varieties of talc have always been a popular for making ornamental
objects."
Snip
"Steatite (soapstone) frequently forms part of schistose rocks."
Snip
"Europe's largest deposits are in Italy and Austria. Talc is today chiefly
used as a heat resisting raw material. for instance in the manufacture of
fire-resistant ceramic material."
Daniel
Date: Thu, 21 Jun 2007 20:13:43 -0700
From: "Anne-Marie Rousseau" <dailleurs at liripipe.com>
Subject: Re: [Sca-cooks] Soapstone Re: Lemon syrup.
To: "'Cooks within the SCA'" <sca-cooks at lists.ansteorra.org>,
"'SCA-Cooks maillist SCA-Cooks'" <SCA-Cooks at Ansteorra.org>
On soapstone sources, our local pewterers guild has several online
resources. You can check them out at:
http://groups.yahoo.com/group/pewterersguild/links/
Supplies_001136519921/
one is Canadian, the other is in the states.
we've also found stone at various art supply places but it tends to
be full of inclusions. Blech!
--Anne-Marie
Date: Thu, 21 Jun 2007 22:45:15 -0500
From: "Terry Decker" <t.d.decker at worldnet.att.net>
Subject: Re: [Sca-cooks] Soapstone Re: Lemon syrup.
To: "Cooks within the SCA" <sca-cooks at lists.ansteorra.org>
Check on United Clays of Texas. They were listed as one of the ten
domestic producers in 1998.
Soapstone has been found near Canton and Bandera City.
Bear
> The only site I've heard of in Texas was a pile of soapstone from an
> old train wreck within a few hours of Austin. Unfortunately it would
> require trespassing on private land to get to it, I'm told.
>
> Stefan
Date: Fri, 22 Jun 2007 19:24:10 -0400
From: Suey <lordhunt at gmail.com>
Subject: [Sca-cooks] Soapstone
To: sca-cooks at lists.ansteorra.org
You have me a bit surprised on this subject as no one has brought up
medieval Muslim use of soapstone pots which seemed to have been normal
fare in the Arab world in medieval times. Perry points out that they
were used as they did not change the flavor of or discolor food. He goes
onto say that they are durable but can break due to physical shocks.
Harisa and other foods that are beaten were not cooked in them.
So some reason that I cannot remember they were never adapted in Spain during
the occupation period. We used some other product for out pots and pans
which I shall remember after consulting a pillow cause we had this big
thing about throwing pots out after the first use. Was soapstone too
expensive for us to do that then?
Suey
Date: Sat, 12 Jul 2008 18:50:08 -0400
From: Gretchen Beck <grm at andrew.cmu.edu>
Subject: Re: [Sca-cooks] Soapstone pan or griddle?
To: Cooks within the SCA <sca-cooks at lists.ansteorra.org>,
sca-cooks at ansteorra.org
--On Saturday, July 12, 2008 3:32 PM -0700 Lilinah <lilinah at earthlink.net>
wrote:
<<<
Does anyone know more about cooking with soapstone pans? Special benefits
or problems with them? (well, other than potentially dropping and
shattering them) Where to purchase them?
>>>
A quick websearch suggests that they heat very evenly and retain heat for a
long time. It's also ph neutral so it won't react with food.
Here's a couple of companies:
<http://www.soapstonecooking.com/>;
<http://www.cooksite.com/IBS/SimpleCat/Shelf/ASP/Hierarchy/0K.html>;
toodles, margaret
Date: Sun, 13 Jul 2008 10:43:46 -0700
From: Dragon <dragon at crimson-dragon.com>
Subject: Re: [Sca-cooks] Soapstone pan or griddle?
To: Cooks within the SCA <sca-cooks at lists.ansteorra.org>
Gretchen Beck did speak thusly:
<<<
--On Saturday, July 12, 2008 3:32 PM -0700 Lilinah
<lilinah at earthlink.net> wrote:
<<<
Does anyone know more about cooking with soapstone pans? Special benefits
or problems with them? (well, other than potentially dropping and
shattering them) Where to purchase them? >>>
A quick websearch suggests that they heat very evenly and retain
heat for a long time. It's also ph neutral so it won't react with food.
Here's a couple of companies:
<http://www.soapstonecooking.com/>;
<http://www.cooksite.com/IBS/SimpleCat/Shelf/ASP/Hierarchy/0K.html>;
---------------- End original message. ---------------------
They also have the nice property of being rather non-stick as well.
When properly polished and kept free of scratches (they do scratch
easily), they are wonderful to cook on.
It's also a very easy material to carve which is one reason it was
used to make pots. Griddles are easy, just get a flat slab. There are
people out there you can buy soapstone from but it is likely you will
only be able to get rough stone or prepared slabs and not finished cookware.
Dragon
From: Fvigil at aol.com
Date: July 24, 2008 4:34:33 PM CDT
To: pewterersguild at yahoogroups.com
Subject: Re: [pewterersguild] soapstone sources?
stefanlirous at austin.rr.com writes:
>So how good is the carving quality of this Brazilian soapstone?
A slight warning.
Due to the nature of soapstone, its quality can change quite a bit within the same quarry - even within a few yards or feet. I've had multiple suppliers send me block after block of very nice stone, then had the next one be full of inclusions, or cracks, or ribbons of harder stone. Heck I've had one 50# block where the first slabs off the end were perfect, and the other end of the block was crap.
If you've generally been happy with a source, odds are reasonable you will be the next time as well - even if you once got lower quality from them. But its almost always (at least to a degree) a gamble.
That said, I'm generally pretty pleased with Brazillian Green from the Complete Sculptor in New York, or the grey-green stone sold by Lee Valley in Ontario.
Fernando
From: Daphnebd at aol.com
Date: July 25, 2008 11:46:18 AM CDT
To: pewterersguild at yahoogroups.com
Subject: [pewterersguild] Re:soapstone sources?
Hello Stefan!
Stoneman Distributors: http://www.stoneman.ca/
Owner/Operator: Robert Morgan. Great guy to work with and very reasonable. I have ordered from him 3 times now, each time anywhere from 30 to 100lbs. Including and depending on shipping, each 3x3x1 slab costs me approximately $3 - $5 per ($5 was when I did a rush order and had to have a special delivery).
When ordering, ask for soapstone used for makings mold for pewter casting. Heck! You can even tell him that Bernadette Dionne recommended him to you! Might get me a little bonus next time I order! hehehe!
He gets a lot of his business from folks like us, so he knows that we want clean stones, with very little inclusions and fissure lines. The stone is very easy to carve and pretty durable too. I've had some detail breakage (after numerous pours) but have always been able to epoxy the break back together, so far!
The stone colors range from tan to a brownish-grey-green, all from the same 3x3x5 slab (he also sells 4x6x? slab). He will cut these down to approx. 1" thick blocks, and I don't believe he charged me anything extra for the cutting.
The cuts are pretty even, but the stones still need to be sanded smooth.
I agree with Fernando, too. Fernando used to be my pusher, um, I mean I used to buy my blocks from Fernando when I lived in Calontir (he also got me started in this addiction!). Quality can really range. I've gotten a few pieces from Stoneman that I wouldn't sell to anyone, but I can & do still use them.
Lee Valley does have some really nice stone, but I don't know if they will cut it to size for you.
Dafne
From: Brian Ferguson <derianlebreton at gmail.com>
Date: January 15, 2009 3:49:19 PM CST
To: pewterersguild at yahoogroups.com
Subject: Re: [pewterersguild] Casting in Stone vs Silicone
<<< You can, however also use finer stuff like the "Italian green" or "African wonderstone". >>>
I'm no geologist, but I think "african wonderstone" and soapstone are two different beasts. From what I've read the former is primarily pyrophyllite, while soapstone is primarily talc.
<<< I know the extant molds I have seen in museums are not the soft powdery stuff that most folks seem to use. >>>
I asked Robert Macpherson a while back about medieval mold materials.
Here's what he posted:
<<< I just ran through our file folder on molds and noted which stones were mentioned. I was surprised to see that we have info. on about 100 mold fragments. Here are the results.
33 were identified as slates (or perhaps shales). incl. Fr. schiste, pierre schisteuse, pierre schisteuse noir, Nd. leisteen.
31 were unidentified.
13 were identified as some sort of limestone. incl. Fr. calcaire, Nd. kalksteen. A couple were specifically identified as lithographic limestone.
11 were identified as sandstones. incl. Fr. grs
5 were identified as calcareous mudstones.
3 as calcareous clay(!)
2 as soapstones (This surprised me; I had not, until today looked up the Nederlands word "speksteen")
1 calcareous sandstone.
1 "calcareous stone of soapy texture"
1 of cuttle bone" -Derian. >>>
From: Fvigil at aol.com
Date: July 25, 2008 11:50:51 AM CDT
To: pewterersguild at yahoogroups.com
Subject: Re: [pewterersguild] Re:soapstone sources?
In a message dated 7/25/2008 11:47:14 Central Daylight Time, Daphnebd at aol.com writes:
>>Lee Valley does have some really nice stone, but I don't know if they will cut it to size for you.<<
Nope - they won't
Fernando
From: Alex Haugland <ahauglan at gmail.com>
Date: February 20, 2009 1:30:25 AM CST
To: pewterersguild at yahoogroups.com
Subject: Re: [pewterersguild] Making Buttons - Soapstone Question
A slight amendment to this.... If you choose to use a bandsaw make sure your soapstone is free from iron pyrite. I unintentionally ground the teeth off of the bandsaw blade I used by cutting up some pretty crappy soapstone (it didn't carve well either). Fortunately, though the blade doesn't work well for cutting wood without burning, it still cuts soapstone fine, so I now have a dedicated soapstone blade. I do agree, though that you can cut with a wide range of tools, including cheap handsaws. Don't use anything too nice and you'll be fine. I'd recommend a finer toothed saw rather than a coarser one, at least for hand tools. 3 part molds aren't horribly tricky to do. If you're pouring pewter registration pins, make sure to flatten the cut edges before drilling the holes for the pins or things won't line up neatly without a gap. A brick is a really simple solution for flattening (and probably pretty period, at least in idea). I generally use a stationary disc sander, but I make sure to wear goggles and a mask as the powder gets everywhere, even with a dust collector. You can also use a piece of coarse sandpaper on any flat surface.
--Alysaundre Weldon
Barony of Adiantum, An Tir
Anne-Marie Rousseau wrote:
<<< On making button molds.
First off, what fun! I love doing buttons. Theyre little and cute and uber period and folks need lots of them.
For cutting soapstone, I have to admit I dont use any sort of special tools. I know some folks use their band saws, or jigsaws etc and they get lovely straight clean lines. My first mold? Was cut with a tree saw! I then burnished off the saw lines. By rubbing my stone on a brick. Again, not fancy but it worked ok.
That said you may be able to find someone to prep you some moldsone of the joys of soapstone is that its soft enough it wont wreck woodworking saws, etc (the dust gets EVERYWHERE tho, so be sure to wear a mask (even a damp bandana) and if your saw has a dust collection system on it so much the better...
Good luck!
--AM >>>
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