Pickling, Swelling and Shaving

Submitted by Matt Richards on 4/11/06 at 6:45 PM. ( ) 70.98.218.168

We're pickling some skins with citric acid using Rittel's recipe of 3oz citric acid to one gallon of water to one lb of salt. With our water this brings the ph to 1.8. From reading and watching Rittel's video on shaving I get the impression that the hides should swell some before shaving, that it makes them easier and more predictable to shave.

However, the salt is there to inhibit swelling, and our experience is that the hides don't swell at all, even after a week. I'm familiar with strong acid or alkaline swelling (we're leather tanners primarilly).

My question is, is the firming or swelling that is expected prior to shaving, the same or similiar to the type of acid swelling you'd get if you didn't use salt, or is this just a matter of degree?

Today, we cut the amount of salt used by half (1/2 lb to 1 gallon) to see if we could get it to partially swell. Any suggestions would be greatly appreciated!

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Alkaline swelling?

This response submitted by oldshaver on 4/11/06 at 8:59 PM. ( ) 68.221.76.64

Alkaline equals hair loss. Bump you salt back up, or you are going to damage your skins. The acid swelling you get without salt is very harmful to the skins, and they arent the same. With salt- firm swell, without salt-rubbery(jelly). You cant learn sahving from a video! I could say alot more, but I dont have time.


squeegyman

This response submitted by B .A .H. on 4/11/06 at 11:55 PM. ( ) 216.198.104.201

Matt, first of all remember that Rittel is trying to sell something.Thats all I'm going to say about that. If you are tanning mostly leather then you should talk to someone who has alot of experience with that process. Call some of the larger leather companys and ask them who some of the good old leather tanners are. One who comes to mind is Monte Sink. I hear he is still very busy so he may or may not be willing to talk to you but it's worth a shot. Good luck


Controlled swelling is tricky!

This response submitted by Bruce Rittel on 4/12/06 at 12:53 AM. ( rittel@mindspring.com ) 207.69.137.13

Don't try controlled swelling. Yes - it has been done, particularly in the sheepskin leather industry - but unless you know exactly what you are doing - like "old shaver" said - it can produce distasterous results! Like extremely weak leather! Take his advice - dont do it! Normally good relaxation - then into the pickle will produce great results and excellent plumping for shaving purposes.


Plumping vs Swelling

This response submitted by Matt Richards on 4/12/06 at 1:51 AM. ( ) 70.98.218.245

That's my question right there. I know what rubbery swelling looks and feels like. But when you and others say the pickle should produce 'excellent plumping' I just don't see it. Our pickled hides just look and feel like any fully soaked hide does whether its soaked in water or a pickle. They don't seem any firmer. And we're very careful about the recipe for citric acid, 3 oz to 1 lb salt to 1 gallon water for at least 3 days at room temperature. Ph is 1.8. I don't have a salinometer but will probably order one soon.

We're going to go visit a taxidermist who pickles and uses a fleshing machine next week so we can get a better idea of how the hide should look and feel when shaving. The Eager Beaver is a nice machine. I love how quiet it is.

PS:

Oldshaver: we use alkaline swelling in leather tanning, don't worry thats not what we're doing with our furs.

B.A.H.: I've been tanning leather full time for 16 years. Tanning hair-on hides with a pickle is completely new to us though.


Matt - Notes

This response submitted by 9 on 4/12/06 at 3:53 AM. ( ) 216.144.58.47

Are you one of the Braintan 'Hide-Out' regulars? I think I have seen many of your posts.

Osmotic swelling from can give you a large loss of tear strength. That means skins which finish up tanned, but then you go to tumble or stake them and they rip like paper. They aren't dry rotted, just so weakened that this happens.

It is not common, in all the hundreds of pelts I've done without any salt in the pickle, I have only had 3 show this problem -- even if I later sent them to a commercial tannery for retanning. It is most common in fox.

You may wish to use a different pickling acid. The problem is probably the weakness of citric acid and it being taken in to the skins and losing it's effectiveness. You will get excellent swell from oxalic acid, and if you are not concerned about indoor safety you will get even more buttery swelling from formic acid. You get much more shrink later with formic though. Again, skins treated with oxalic or formic can even be re-tanned commercially with no quality loss.

Here's an example from today. You may wish to use this species or other squirrels due to their abundance and thickness of the skins. I had a groundhog, fresh. I skinned it (leather thickness under 1/16") and then put it directly in to a pickle of straight oxalic acid, Dawn, and water which was very strong, pH .9. I left it in there for 3 hrs. until it had turned milky white all over, shrunk to half it's size, and had a thickness of over 1/8" on the neck and back. This is typical of groundhogs as they have a very thick hide. The ground substance of the hide was so gelatinized that it was sticking to my gloves during shaving. I shaved it down all over which was easy, and did all of the turning. Then I put it back in to the strong pickle, took it out 2 hrs. later, touched up the shaving, then neutralized for 10 min. Then placed it in to the tan which contained a lot of salt, 1.5 lbs to 1 gal tan. Got all the stretch and size back and totally lost the jelly feeling. The leather remains a little thicker then when the pelt was skinned but that is from uptake of tannins and is normal.


Yep

This response submitted by Matt Richards on 4/12/06 at 11:49 AM. ( ) 70.98.218.245

That is me at the Hide Out. Some of the folks there pickle their furs, but they don't know as much about it as the group here. Still looking for more insite on the plumping vs swelling question in the post above.


I have just

This response submitted by Mike on 4/14/06 at 12:03 AM. ( ) 63.232.53.37

experimented with the so called safety acid, and I don't think it does a darn thing. I did a squirrel, a groundhog, a mink, and a muskrat and all after the safety acid pickle came out slimy, raw and unfleshable. I used to use the 24 hr prepickle with alum and salt. I used anmmonium alum and aluminum sulfate and got much better firming and plumpness and could shave and thin after 24 hrs in this. then tanned with liquatan. i never had these problems. I pulled the skins out of the so called safety acid, and they still were slimy raw skins. no way i could have shaved them or done final fleshing. followed all directions even left some in for week and a half. I will be going back to the alum and salt brine pre pickle for my skins. just my experience and the ph was just fine too.


You ok Mike?

This response submitted by jrosbor on 4/15/06 at 5:32 PM. ( huntersdream3x@hotmail.com ) 64.73.36.192

First off, I know it is called Saftee Acid. Not "the so called safety acid". I have used Saftee Acid for years and I must say I like it. Is there better acids on the market? Yup. And they cost about twice as much to use them but I like them too!

You are talking about using an Alum pickle. This is a bit diferent than any other acid pickle I have ever used. And I have used a lot of acids for pickles. Ya know... Back in the day, we used the alum pickle as the tan by just adjusting the pH up to about 4.

Ya ever think it's called Saftee Acid for a reason? Like maybe it's more safe than other acids?

I am going to prep a page on acids just to maybe set the record straight.

Later taters! Joe


Yeah I'm fine

This response submitted by Mike on 4/15/06 at 6:17 PM. ( ) 63.232.26.119

what would you recommend? I don't understand the point you are trying to make. All I got from that was you like saftee acid. I understand the part of the alum tan. All I used to do was use a salt and alum prepickle to plump the hide and firm the tissue and meat to flesh easier.That was on deer hides. So why did my skins do what they did? Please explain a little more in detail. I wasn't trying to to sound like a smart a$$ if you took it that way I'm sorry. I'm just trying to tell my experience about plumping and swelling as the post suggests. Any help is appreciated. Thanks


Oh

This response submitted by Mike on 4/15/06 at 6:26 PM. ( ) 63.232.26.119

I can see what you were saying about me calling it so called safety acid. yeah that sounded stupid. It is called safety acid. what I meant was does it even work? at all. I dont have much experience with acid pickles. Like I said I used to use ammonium alum or aluminum sulphate to plump and swell my deer hides so I could flesh and shave. So what went wrong with the skins? Thanks


The page I am doing...

This response submitted by jrosbor on 4/16/06 at 1:18 PM. ( huntersdream3x@hotmail.com ) 64.73.36.192

Will explain every thing. Wasn't trying to open a can of worms, But it doe's sound that way. Acids are a touchy subject in taxidermy.


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