lea-tanning-msg - 7/22/04
How to tan leather. Types of tanning.
NOTE: See also the files: leather-msg, lea-tooling-msg, leather-dyeing-msg, lea-bladders-msg, leather-bib, leather2-bib, parchment-msg.
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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.
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Mark S. Harris AKA: THLord Stefan li Rous
Stefan at florilegium.org
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From: cav at bnr.ca (Rick Cavasin)
Subject: Re: Waxed Leather
Organization: Bell-Northern Research Ltd.
Date: Wed, 7 Jul 93 17:06:22 GMT
Greetings from Balderik,
gleason at scf16.scf.loral.com (Robert Gleason) writes:
|> I've noticed that the comments always say to use vegetable tanned leather.
|> Why not chrome tanned leather? What are the differences between the two
|> processes?
|>
|> Lord Parlan MacGillivray
The short answer is 'It don't work with Chrome tanned leather'.
I don't know the details of the chemistry off by heart. The best source
I've got, Reid's 'Ancient Skins, Parchments, and Leathers' gets into some
of the details, but it's at home. I'll try to give a 'readers digest' version,
which should be taken with a grain of salt:
Basically, one of the characteristics of Chrome Tanned leather is temperature
stability. Something about the way the chromium sulphate binds to the pelt
fibres stabilizes them. With veg tanned leather
on the other hand, something about the way the various tannins bind to the
pelt fibres allows a peculiar polymerization reaction to take place above
a certain temperature. The cuir bouilli is distinctly different structurally,
and chemically (?) from the leather you began with, apart from any wax/hardener
you may have added in the process. I've hardened vegetable tanned leather
without using wax at all, and only added wax afterwards to enhance the effect
by making the leather denser and more waterproof.
You can bake/wax chrome tanned leather, but it won't undergo any dramatic
increase in rigidity (as far as I know).
Although most people don't care, chrome tanning is not period. Whether or
not modern vegetable tanned leathers resemble their period equivalents is
beyond my knowledge, but I believe there are some distinct differences in the
production methods.
Cheers, Balderik
From: cav at bnr.ca (Rick Cavasin)
Newsgroups: rec.org.sca
Subject: Re: Costuming and boots
Date: 27 Jan 1995 14:50:25 GMT
Organization: Bell-Northern Research Ltd.
mwl at celsiustech.se (Matt Larsen) writes:
|> Robert G. Gleason (gleason at scf16.scf.loral.com) wrote:
|> : IMC at vax2.utulsa.edu (I. Marc Carlson) writes:
stuff deleted....
|> Also, for whatever it's worth, chrome tanning is a modern process, and
Yes, and modern vegetable tanning is also a modern process, with some very
important differences from how it was practiced in the middle ages.
Saddle skirting, and many (but not all) of the vegetable tanned leathers
commonly available today, are made to be firm, with little stretch. They
don't HAVE to be that way. I've made vegetable tanned leather that was
quite supple, with alot more stretch than what one would expect, and it won't
take tooling the way modern veg-tann does. What was medieval veg-tann like?
I don't know myself. Been too busy researching other stuff. Someday, I'll
get back to the veg-tann experiments. Hope it's before the next move, don't
want to carry that garbage can full of oak bark around with me....
|> all period shoes would have been made with vegetable tanned leather.
^^^
I don't know about 'all'. While shoes for outdoor use would in all likelihood
have been made from vegetable tanned leather, I suspect that some fancy indoor
shoes would have been made from alum tawed skins. It would have been
particularly attractive because it is it white, and takes a wide variety of
the dyes available at that time quite well.
If I recall correctly, 'cordwain' leather was one term used for alum tawed
skins. Medieval shoemakers were called 'cordwainers', so logically....
Always best to avoid absolute statements....just in case.
About the chrome tanned leather, I think alot depends on HOW the chrome tanned
leather was made. If it was made to be soft and stretchy, I agree that problems
can arise. But chrome tanned leather can be quite firm. Not that I'm a big
fan of chrome tanned leather or anything.
Cheers, Rick C. (who still wears his boots whose uppers are made of chrome
tanned leather - I think they're on their 4th set of soles - may not be pretty,
but they're not shapeless lumps either!)
From: cav at bnr.ca (Rick Cavasin)
Newsgroups: rec.org.sca
Subject: Re: "Authentic" crafts and the SCA
Date: 7 Mar 1996 16:26:20 GMT
Organization: Bell-Northern Research Ltd.
schippnick at aol.com (Schippnick) writes:
....snip....
|> the price is similar. Their process uses the animal's own brains. ("Every
|> critter has enough brains to tan it"s own hide")
I've always heard it as 'God provided every animal with just enough brains
to preserve its skin', which is, IMHO, a more clever play on words.
|> Brain tanning seems to
|> result in an excellent, supple, durable product. Does anyone know of it's
|> use in early Northern Europe?
Brain tanning is a form of oil tanning. The brain is rich in various lipids.
Most of the recipes I've seen involve
an additional source of grease/fat, and sometimes soap. If done properly,
it can indeed produce a very beautiful leather. From the descriptions I've
seen, and from speaking to people who have done it, it appears to be a VERY
labour intensive process. Anyone who does traditional smoke/brain/buck tanning
deserves to get a princely sum for the product.
I have not seen any references to brain or smoke tanning in medieval Europe.
However, oil-tanning or chamoising was commonly done, sometimes in combination
with alum-tawing.
Medieval 'buff' leather, used in armouring for points and buff-coats might well
represent a close parallel to Amerindian brain-tanned leather (NOTE: not all
amerindian buck-tanned or smoke-tanned leathers include brains in the tannage,
though the products are often similar in character).
The grain is removed to facilitate penetration of the oil/grease, and the
tannage takes place when the oils are oxidized. This oxidation is hastened
by smoking in the amerindian tradition.
Hope this helps, Rick/Balderik
From: cav at bnr.ca (Rick Cavasin)
Newsgroups: rec.org.sca
Subject: Re: Help! Leather tanning and prep
Date: 25 Mar 1996 22:52:08 GMT
Organization: Bell-Northern Research Ltd.
DenTim at mail.myriad.net (Tim Lozos) writes:
|> I just today bought a green steer hide (about 55 sq ft, only
|> $40!). now I just have to figure out how to tan it ;) Does anyone have a
|> concise guide to preping and tanning a hide?? Especially to use for armour
|> and such. Any guidence on books, pamphlets, Sca related materials or just
|> an email w/ relevent facts would be greatly appreciated!
|>
|> Tymo (wondering how to explain this stinky pile of fur to his
|> lady)
I'm really sorry buddy, but I gotta say this:
HA HA HA HA HA
HA HA HA HA HA
HA HA HA HA HA !
I know, I know, that's not terribly charitable or helpful, but it's been
a long day (week? month? lifetime?).
$40 is probably a pretty reasonable price for that size of green steer hide.
But I process skins all the time (mostly as parchment/vellum, sometimes as
leather), and I would never tackle such a project. It is very ambitious
for a first timer.
First of all, I will tell you what I tell everyone who asks me about tanning
leather:
As expensive as leather can be at times, it is very cheap when you consider
the amount of work involved in doing it yourself. Most leather is produced
in highly mechanized tanneries with huge economies of scale. There's alot
of labour involved in doing this yourself, and this is especially true for
heavy leathers.
If you're going to try and tackle it, I'd suggest that you cut the hide up
into more managable pieces for a start. That size of hide is tough to
manhandle, and you'll need pretty big vats to hold it in one piece. The
instructions I've included below may work as far as getting the hair off,
but I'm not sure you can alum taw something that thick. I'm not sure it
is practical to veg-tann it, as it takes a long time for vegetable tannins
to penetrate a hide that thick without the specialized equipment available
in a modern tannery.
Tanning instructions from something I posted to someone else ages ago:
I think Tandy currently carries two sorts of tanning kits. One is a tanning
paste, the other is a more complete kit with lime for removing hair, etc.
I've never tried either kit, so I don't know what sort of leather can be
obtained by using them.
|> This means you need to find
|> a recipe for removing the hair.
This is relatively (!) easy:
1) Remove large chunks of fat/flesh from the flesh side of the hide.
(if the hide has dried out somewhat, do this after soaking for a couple
of hours as part of step 2)
2) Soak the hide in cold water, changing the water frequently, for a period
of about 2 days. This is to wash out blood, soluble proteins, etc.
3) While soaking the hides, prepare your unhairing solution:
Take about 2 cups of builder's lime (slaked lime = hydrated lime = Ca(OH)2)
for every 5 gallons of unhairing solution (you'll want about 10 gallons
for the average deer hide - maybe more for an elk).
Mix the lime with hot water (lime is caustic - exercise appropriate
precautions), and set it aside to cool for a day or two. DO NOT PUT
THEN HIDES INTO THIS SOLUTION WHILE IT IS HOT. It is inadvisable to
unhair the hides using lime if the ambient temperature is much over 75F.
4) After the soaking, place the hide in the lime solution in some sort of
tub. Stir as frequently as possible (at least twice daily), and drain
the skin over a horse every day or two, returning it to the lime solution.
5) When the hair at the neck can be rubbed off easily, it is ready to unhair.
The hair can be rubbed off with a gloved hand, or scraped with a blunt edge.
Depending on the state of the hide when the process was started, the species,
thickness, ambient temperature, etc. it will take 1-3 weeks for the hair
to loosen.
Draping it over a cylindrical 'beam' can facilitate the unhairing process.
6) Once the hair is removed, the hide should be thoroughly fleshed to remove
any residual fat, flesh, and connective tissue.
7) Wash the hide thoroughly to remove residual lime. Change the water frequently,
for about 2 days. To be double sure, you can 'delime' the hide after
washing in a weakly acidic solution (eg. very dilute vinegar).
In period, deliming would have been achieved by soaking in a fermenting
vat of bran after thorough washing. I haven't tried the fermenting bran
yet.
8) Your hide is basically ready for tanning at this point.
|> If you have cleaned the skin well (no fat
|> or meat) and have it salted the skin will last for a while. I have two
|> hides in that condition that I have had for a year with no signs of
|> deterioration.
Deterioration can be more subtle than outright putrefication. Residual blood
in the hide may set permanently, leaving blotches in the finished hide. Fat/oils
oxidize, leaving discolourations. There are some organisms that can attack
the salted hide, leaving various discolourations. Some of these things may
not be as big a concern for someone making leather, but for parchment, I like
to get my hands on the skins as soon as they're off the carcass. Unfortunately,
that rarely happens.
Even freezing, though better than salting for prolonged storage, can lead to
problems in the long term.
|> Other hides I have sent to a company in Wisconsin that tans hides and does
|> a beautiful job at a very reasonable price. I pay about 1/3 of what a
|> commercial hide would cost.
This is probably the best route to take. Tanning is alot of work (especially
for something the size of an elk), and there's no guarantee that your first
attempt will turn out.
Here's some references:
Ancient Skins, Parchments, and Leathers, R.Reed, Seminar Press
London and New York, 1972 ISBN 0-12-903550-5
Of all the do-it-yerself type home tanning books, these are my two
favourites:
Home Tanners' Handbook, June Vivian ISBN 0-589-013718
The Complete Book of Tanning Skins and Furs, J.Churchill
Stackpole Books, Harrisburg PA 1983
(sorry, just have a few pages photocopied and no ISBN. Tandy
Leather used to sell this book, and they may still do so)
Hope this helps.
Cheers, Rick /Balderik
From: cav at bnr.ca (Rick Cavasin)
Newsgroups: rec.org.sca
Subject: Re: Help! Leather tanning and prep
Date: 25 Mar 1996 22:56:24 GMT
Organization: Bell-Northern Research Ltd.
On second thought, maybe I shouldn't laugh. My first
tanning project was a moose hide after all. But then,
I'm a self confessed bonehead.
Cheers, Rick/Balderik
From: "david.nelson at anestgsi.uu.se at d (12/14/96)
To: markh at risc.sps.mot.com
Date: Sat, 14 Dec 1996 23:22:39 +0100
Subject: leather tanning
Noticed an inquiery concerning information on brain tanning.I have
written a book on the subject which has recently been translated from
Swedish to english. I have a small tannery in Sigtuna,Sweden where I tan
using only traditional methods such as brain and bark tanning. I also
hold courses on the subject.
Lotta Rahme.
Långgatan 9,
s- 19330 Sigtuna,
Sweden.
The book can be found at http:/www.teleport.com/~tcl/index.html
From: "david.nelson at anestesi.uu.se at david.nelson" at anestesi.uu.se
Date: Tue, 17 Dec 1996 23:27:43 +0100
To: Mark Harris <mark_harris at quickmail>
Subject: tanning
Hi Mark
Thank you for your reply.The ISBN number of the Swedish edition is
91-36-02810-X. I will have to get back to you on the english version
ISBN. My production is small and mostly geared for museums and products
sold in the our adjecent store in Sigtuna outside of Stockholm.I do not
know what the SCB is.I am currently using my husbands adr (thereof David
Nelson). I have ordered an adr. It will probably be
Lotta.Rahme at swipenet.se. Hopefully up and running next week. We have
also registered a domain. Lottas tannery and will eventually construct a
site. Thanks again, and will get back to you on the ISBN nr.
Lotta
Date: Mon, 03 Feb 1997 21:44:51 -0800
From: lotta rahme <lotta.rahme at lottastannery.se>
To: Mark Harris
Subject: Tanning book
Dear Mark!
I have now got my own E-mail address.
The ISBN number of the book is 1-887719-00-8.
I have just been in contact with the publisher and it seems
that, to my irritation, it has not been released yet. It was supposed to
be out in November.
You can get information about the book at : http:/www.teleport.com/~tcl
Best regards
Lotta Rahme
Date: Thu, 17 Jul 1997 14:01:04 +1200
From: "Pete Grooby" <Peter.Grooby at trimble.co.nz>
To: sca-arts at raven.cc.ukans.edu
Subject: Tawed leather
Well met good folk,
I thought i would give an update on my experiments into tawed
leather.
Never being one to let admonitions get in my way, I had a go tawing a
piece of soaked and unwrapped rawhide dog bone.
Rather surprisingly it actually worked. It took about 6 hours or so
to get the leather completely white, although it was about 80% done
within an hour. It seemed to turn the whitest after a realling good
staking, so it could be that the rawhide has been sufficiently
treated that it won't absorb the alum unless stressed.
It came out as a nice white-off white thickish rough leather, that is
moderatly flexible.
I waterproofed half of it last night by rubbing some tallow into it.
I'll try soaking part of it in some water and see how well the
waterproofing works.
I also had a go at chamoising a piece of rawhide, but had no luck at
all with that, I suspect my raw material was not ideal.
Next I'd like to try dyeing some vegetable tanned leather, using
natural dyes. I thought initially I'd try lichen.
I have a book that says that due to the stuffing employed with
commercially tanned leather, water based dyes will not work.
Has anyone had any experience with this? Could I strip some of them
out by first rubbing with some sort of thinner.
Thanks for your help.
YIS
Vitale
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Peter Grooby pgrooby at trimble.co.nz -=0 0=-/
Trimble Navigation http://www.geocities.com/Athens/3069 |_{|}/ /
Christchurch, NZ. _| \
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Date: Thu, 17 Jul 1997 21:13:37 -0400 (EDT)
From: PamD956 at aol.com
To: sca-arts at raven.cc.ukans.edu
Subject: Re: Tawed leather
In a message dated 97-07-17 14:07:33 EDT, you write:
<< I also had a go at chamoising a piece of rawhide, but had no luck at
all with that, I suspect my raw material was not ideal. >>
You could try soaking the rawhide in a saltpeter solution. American indians
used it to break down the fibers in deerhide to make it soft. (See what I get
for going to the Jamestown Settlement? I learn the wierdest things...)
Date: Fri, 18 Jul 1997 09:43:39 +1200
From: "Pete Grooby" <Peter.Grooby at trimble.co.nz>
To: sca-arts at raven.cc.ukans.edu