Leather hardening failure

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Kilkenny
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Leather hardening failure

Post by Kilkenny »

Anyone else ever run into this one... I just did three pieces last night, all from one hide, all handled pretty much the same way throughout the process, all parts of enclosed vambraces. All three went into and came out of the oven at the same time. Two hardened up just like we want.

The third piece just didn't harden. I've run it through the process again this morning and I'll see whether it took in a bit when it has cooled down.

Just wondering if anyone else has run into this problem. (And of course, I'm having this glitch on something with three hours or so of tooling put into it, and that is *part* of something, not an entire piece by itself, so if it doesn't come around I'll need to make a replacement just like it.)

Gavin
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Post by Armoured Air Bear »

Yeah that happened to me as well. one piece was hardened nicely while the other was burned to a crisp. althous that was using the parafin wax method. I've also just hardened it in the oven without any wax, and that has lead me to the best results.

how did you harden yours? also when you do tooling and put it in the oven- the tooling does not distort?

hope you can fix it easily.

Aaron
Kilkenny
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Post by Kilkenny »

I soak mine in a glue and water solution and then bake at roughly 180 degrees for as long as it takes to get them firmed up, but not dry and not hard. I've found if I bake them until they are dry and hard, I get some warping that I can avoid by just not baking quite as long. After cooling off the end result seems pretty much as hard either way.

I don't find that the baking does anything to speak of to my tooling - I think it's the curving of the pieces that produces some moderate disruption to the tooling. When the piece is curved, the edges of the knife cuts tend to "stick up" a bit. Some of the cuts, depending on the direction of stretch from the curving of the piece, will pull open a bit.

There's a definite tendency for stamped impressions to lose definition if they are in an area that gets stretched (or compressed) significantly in forming the piece.

And re-hardening the piece seems to have worked, although it's still not quite as hard as the other pieces.

Gavin
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Uilleag
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Post by Uilleag »

Gavin,

I have had that happen to me as well. I think that it has something to do with the differences in the density of the hide in differnt areas of the leather.

What I have done to over-come this, (and it works 90% of the time), is that I have modified my procedure some. You may want to try this on future pieces.....

1) Soak the leather for 4- 8 hours until it is completely saturated. The goal is to get get every single fiber wet, this activates all of the tannins in the leather and gives you a consistant as possible starting point.

2) I then allow the leather to "case" for approximately 12 hours, (i.e.: over night). The leather has begun to dry and holds its shape really well while forming at this point.

3) Dye the leather directly after forming it, this way it is still damp and the dye penetrates the leather more evenly.

4) Bake the leather until dry at 180 F

5) Then paint the water glue mixture onto the leather, inside and out. This way the leather is already hot, and the pours are open, you will get a much more uniform coating/penetration of the hide this way.

6) continue to bake at 180 F until the glue is dry.

You will want to check the piece every 15 - 30 minutes to ensure that it is not becoming mishapen or over heated. I have not had any pieces come out like you described in your original question since I have modified my procedures to this order.

Good luck!
Uilleag
Kilkenny
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Post by Kilkenny »

Dan, thanks for the tips. My normal practice pretty well covers the casing side of things, but I think I'll have to experiment a bit with heating the leather and *then* going to the glue solution - I think you have something about better penetration into warm leather.

The piece seems to have come around acceptably after a second pass through the glue bath and the oven. Interesting note - when I put it into the glue bath the second time around, it never absorbed enough to submerge completely. "Fresh" leather sinks in a matter of seconds.

Gavin
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