I have a question on dry tanned hides. What would cause a different degree of shrinkage from different commercial tanneries? I never really noticed before but I sent 2 different bear hides that measured within 2" of each other. When they came back there was 10" difference between the 2. My question then is, do different tans cause a different degree of shrinkage? Is it because it is not tanned thoroughly? Is it because there was not the same degree of breaking?Since that difference was all there at one time will it return when rehydrated? Both tans appear to be soft,pliable, and clean. Thank you for any information, Martin
Normally most hides tan reasonably close. I must admit 10" is quite a bit. Is that your head to tail measurements on the Bears that you were comparing? As to your questions -
1) Yes, certain tans do cause different shrinkages. However, if you had them both tanned by the same Tanner - it's doubtful he used 2 different tans on them. Normally Alum tends to shrink the skins slightly if you compare one to a Lutan F or EZ-100 tanned skin. But this is normal, since the Lutan F and EZ-100 both tan fairly close to size and Alum doesnt. Don't worry though - the Alum skin stretches out when you relax it. The size comes back.
2) Thoroughly tanned? Yes - if one was and one was not - but not probable usually. Cut a sliver from the edge of the smaller Bear and examine its cross-section. If it has a distinct brown center, it is an indication it is not a full tan. If it is the same color (usually white) all the way thru - its tanned. But even an uneven tannage wouldnt account for a 10" difference.
3) The more likely problem with the difference may be in the way they "broke" the skins. I know I used to do my own Bear rugs and I arm staked them soft. This means you tend to stretch them in different directions as you work. Staking machines also will do this. The good news is, if it was distorted during "breaking" then the size will come back when you rehydrate it. Its kind of the same problem you will have when pulling a cape onto a form and you find you no longer have a brisket - and then you find yourself pushing the cape back and pulling on the seam (in a different direction) instead.
I'm assuming you got the skins back with your punch marks still intact, so a mixup is not an option. Otherwise I'd check with your Tanner. Sometimes this will innocently happen, even tho most Tanners try very hard to minimize a mixup.
Bruce Rittel
Rittels Tanning Supplies
Yes Bruce those were nose to tail measurements. One tannery uses sulphuric pickle and Alum tan. Other tannery uses formic pickle and Lutan-F. They seem to be tanned all the way through, I was just suprised at the difference in shrinkage. These two bears were young bears, siblings. After they were fleshed and salted lying on floor I happened to measure them and there was 2" difference. Otherwise I might not have even noticed. Like you said they probally will relaxe back closer. I will keep track and see. Thanks for your time, Martin.