Leather "Curling-up" after tooling...

[JRedding]

I guess I'm the odd man out here I don't case leather to tool it, I've tried it but just never loved the results. I've experimented a lot and came up with different conclusions that work for me. The leather we get today is not the same as it was back in the fifties , sixties , or probably the seventys, I hung out in the old Newton Bros. shop here as I'm sure many of you have the old local saddleshop, the leather they dealt with back then was harder than a jailhouse door, it wouldn't mold to shape without hot water, and it wouldn't tool without casing, thirty or forty years later the EPA has forced the tannerys to re-invent the process several times since most of the literature people are referring to was written. It's kind of a case of nothing stays the same and the changes in the tanning process have definately changed the behavior of leather. I don't case to tool because I don't feel todays leather is so hard I need to for it to accept it. As everybody knows casing allows the moisture time to penetrate and even out throughout the thickness of the leather, thus the back becomes as formable as the front making it easier for the leather to stretch. By leaving the back as dry and hard as I can it retains some of it's own rigidity helping it hold it's shape. Something like moistening it and then taping it to try and control it except without all the extra steps. I tape small projects made out of lighter weight leathers and then moisten from the top down and have little to no stretch, but leather in projects like that have almost always been leveled on the back that's a different thing. Leather being a product of nature has a knit all it's own that holds it together, once it's been leveled the knit of the fibers has somewhat been destroyed it no longer has a top and a bottom it only has a top and a middle once it's been leveled, and it no longer has near the ability to hold itself together that it once had. Taping and scrimping on the moisture as much as possible really helps me control the stretch on leveled leather. In a nutshell you're not tooling deep enough you're into the bottom layers of a piece of leather if the surface you're working with isn't so hard you have to case it to be able to tool it why do it ? I've just had my best results by trying to get the moisture in the portion I'm working with and leaving the portion I'm not alone as much as possible. I'm sure others have drawn different conclusions and as long as it works then it's a good conclusion this is just my approach.

[pete]

Fascinating! So you just maybe run a dampened sponge over the belt as you are working that area?

pete

[JRedding]

Fascinating! So you just maybe run a dampened sponge over the belt as you are working that area?

pete

Pete, I use a spray bottle instead of the sponge and I wet the whole piece pretty well I like to carve wetter than I tool just because it's easier, by the time you've finished carving it's dried enough to tool , that kind of depends on the size of the project but that's the basic idea. then you can just spray it a little bit to keep the moisture consistant. It's just a practice deal learning to read the leather, some leather seems to return faster than others and here it varies from summer to winter, you have to feed it a little different in August than you do in January but once you've learned the look and feel of what you want it's not so hard. I just don't beleive there's a formula that's correct and always works well, like you can take any brand of leather of any weight , and at any climate and case it for a set amount of time and it's going to hand you back the best results possible to be tooled. Learning to read the leather and make adjustments for what you've got at hand will make a lot of leather give you good results as opposed to just treating it all the same, and wondering why one piece is so agreeable and the next isn't. Casing is pretty much a set formula, you're going to case it long enough it balances the moisture throughout it's layers, I just think it may have worked better when all the leather was tanned with basically the same process in every tannery and it was a lot harder leather than we see today.

[BillB]

My experience over the last 40 years is a mix of all the comments already in this thread.

The quality and the tanning of the leather has changed over the years for better or for worse. :mellow:

I have cased, quick cased and not cased at all. When I case the leather, I let the moisture penetrate and equalize through out the thickness of the leather. I then allow the leather to dry until the surface and the back have returned to their natural color, but one can still feel the coolness of the leather caused by evaporation when it is held to ones face cheek. Some folks call this reading the leather.

I have also found that leather, a skin, is held in natural tension by the fibers, as previously stated. When one cuts the fibers on the tooling surface, that natural tension is broken, it is further disturbed by tooling, remember we are not removing material but compressing it. That compression set up a new tension in the leather. Depending on the thickness of the leather and the depth of the tooling and the size of the design in relation to the leather (tooled versus not tooled) has a lot to do with the amount of change I impart on the the original piece of leather whether that be in size (length or width) or its ability to lay flat.

Since leather is skin, I have also found that the dyeing process can also impact this problem. Skin likes to have natural oils in it to stay flexible. Dyes are solvents that first must suspend the dye to transport it to the fibers. It must then replace the natural oils in the fiber so that the pigmentation of the dye is transfered into the fiber. It then must evaporate to lock the pigmentation in. This process tends to remove all oils from the fibers and changes the tension in the leather/skin. Have you ever used a cleaner on your hands to remove the dye stains and ended up with rough and cracked skin? Same process. Putting oils back into the leather will help resolve the condition the dye process has created, but not the change the tooling process has done.

I guess that is why well tooled leather is still an Art or Craft. It is impossible to replicate with a standard process or by machine.

Lets hear it for all those Artist and Craftsmen/folks/people that are out there. :D

Have I now :deadhorse: