when i buy an intersort of hides/pelts, this is how the big auction houses sell them. i relax and then pickel them. some of those pelts may have been dryed with borax added. now borax we all know is highly alkaline. this will cause week acids to raise above the desired point on the ph paper. now sulfuric acid will hold at one or 1 1/2 very very well. this is how i started using sulphuric acid. my first attempts [years ago] at relaxing were incomplete at best. and with borax residue present in my pickel the ph was not holding well and those "safe" acids were not very good for me. i like what david patton says "any acid not properly neutralized will rot your hide"
but i have some concern now about lead. does all sulphic acid contain lead? i'd like to add that bruces Rittels statement about acids "bottoming out" has caused me to you sulphuric acid in my pickel at about 25% higher concentrations than the reccommended 1/2 oz. per gal.
any one with any thoughs or knowledge please jump in here. hold your put down remarks to a min. please. unless you feel the need to vent. im in a learning mood presently, but love them fights too!
i would also like to hear about anyones disasters on neutralizing. come on now, i know you've had them! if your worth your salt at tanning that is.
Return to Tanning Category Menu
The good fights or the tannery wars that have been going on for years here are what I like to refer to as heated discussion. Passionate expression over a subject that I love dearly...tanning. There are many ways to tan, and we all have our favorite ways. We also like to defend our personal tanning methods. If we can remain professional and stay away from character assasination, then we can enjoy a difference of opinion.
Anyhow, sulfuric acid has its place in tanning. I would use it sparingly and use all precautions when handling it. I would also reserve the use of sulfuric acid on only heavy hides such as rhino, hippo, elephant, and giraffe. You will need to know the proper formulation for the pickle to be effective with using this type acid. New tanners can get themselves into a bad spot if they are not careful with this highly corrosive and reactive acid.
For all other types of skins, in a custom tanning house, I recommend formic acid. The guys tanning at home or tanning in a taxidermy shop can order small amounts of product from the taxidermy tanning suppliers that are very safe to handle and have specific trade names that I will leave out here.
Formic can be bought in bulk and is economical for use in tanneries that are soaking up many skins in many vats and drums. It can be bought in different concentrations and applied in different strengths depending on the type skins that are being run.
Properly neutralized, tanned skins should last many years without experiencing acid rot. This neutralization is where a lot of tanneries cut corners in an effort to get batches run through quickly and save money on the bottom line. Unfortunately, it will tell on you in the long run. This improper neutralization has caused many to claim that humidity reacts with the chemicals in the tanned hide to create sulfuric acid. This statement has credence when you consider that sulphates and water can do that. However, the much simpler explanation is that the tanned hide did not spend enough time in the neutralization step. A good test is to take a piece of tanned hide and cut a cross section away, wet it, and place a pH test strip against the layer just below the surface. Does it show acidic or not?
Have a good one EJ and get ready for more to come!
NO SULFURIC ACID CONTAINS LEAD. Now if you're a cheap sucker and use battery acid recovered from old batteries, then it certainly WILL contain lead but then it's a new chemical combination all together. I guess it would be H2SO4Pb. If you BUY sulfuric acid, you get pure sulfuric acid.
Cyclone pointed out that sulfuric acid from used car batteries contains lead. I think EJ may have misunderstood what Cyclone was talking about.
thanks for the answers goes to patton and george. george pattoon like the great general.
i really appreciate it. i do disagree with davids opinion about sulphuric acid corrosiveness. i've tanned the thinnest skin kit fox pelts with no adverse effects. i mean they are paper thin hides from the desert southwest. i do not think sulphuric is harsh in the pickel. and i've noticed a real suface softness to the leather side. of course im strickly a fur tanner. not experoienced in leaether only. sorry bout the type o's my new sony viao cumputer has a very sensitive touch.
also when some of this pickel gets splashed in my eyes there is no pain. it must be a natural compound fluid as i just tanned another batch of 15 year old coyote and they turrned out beautiful.