Does Deep Stamping Hurt The Leather?

[StrigaMort]

On my second sheath my stamping got kinda washed out when I was folded over (pouch style sheath). I guess the fix is just to hit harder to get a deeper impression? Does heavy handed stamping weaken the leather?

I'm using a junk Tandy basket stamp and poly mallet. 8/9oz Hermann Oak leather.

Thanks!

[oltoot]

With most stamps its hard to stamp too deep with basket stamping being one of the possible exceptions due to the sharpness of the ends of the legs on some stamps. As long as the stamp doesn't cut through fibers the compression of fibers actually makes leather more durable. With most stamping done today, it is about a wash with enough fiber compression taking place to balance out any weakening from fiber cutting. In addition to hitting harder, paying closer attention to getting the casing just right and finally, when molding if you will develop the habit of wetting pieces from the inside. For sheaths like the one in the picture you could just fill the sheath with warm water and pour the water out when you first begin to get wet spots showing through. That will help a great deal with keeping impressions looking as crisp as they did when you finished stamping them.

[StrigaMort]

Thanks! That all makes sense.

One correction, and an additional thought...

Thinking back, it wasn't when I folded the leather over, but when I wet molded the leather to the handle, that the definition started to fade. I think pressing on the leather and using the bone folder were what created the problem.

You mentioned the legs on the bw stamp. Looking at the sheath, it seems that the legs make a pretty deep impression when compared to the rest of the stamp. The impressions that you see in the pic nearer the bottom (where there was no wet forming, that is, the blade area) are pretty much how they looked pre-dye/forming. Is this because the stamp legs effectively get hit twice by overlapping, or because I'm using a less than good stamp? Maybe it's my technique? Would it be advisable to try and grind the legs back a hair? I'm pretty comfortable with the idea, but I don't want to ruin the stamp.

[WyomingSlick]

Does heavy handed stamping weaken the leather?

Thanks!

Does Deep Stamping Hurt The Leather?

Its a good thing you modified your title question in your post, or I would have to tell you how my leather weeps for hours during/after stamping. LOL

But seriously......of course, stamping/carving weakens leather. Ask any experianced leather worker which 2 inch strap he would choose to hang from over a 100 foot fall.....two straps cut from the same hide, side by side.......... one strap being tooled...and the other untooled?

That is why, except for fancy show saddles, you do not see tooling on a saddle's crucial parts that are heavily stressed. The jockeys, the fork, the seat, cantle, skirts,and fenders may all be heavily tooled, but the latigos, cinch straps and the stirrup leathers will not be tooled at all.

The same applies for belts. Tooled leather belts are for holding up your pants, and showing off.......untooled and perhaps reinforced belts for utility use like lineman belts, climbing belts, tool belts, etc.

The fact is that most stamps cut the leather and weaken it to some degree, and of course a swivel knife cut definately does. The sharper the edges are on the stamp, the more it will cut the leather. Toolers like to talk about the "crispness" certain stamp makers tools have,but the fact is that such tools cut the leather more than a less crisp, that is, a blunter stamp.

Does that matter in most applications? No, it doesn't since the remaining strength of the leather is sufficient in most situations. What may be of concern is tooling in areas that endure a lot of flexing and movement during use. For example, a good carving or stamping design for a billfold, or wallet, will have a minimum, or no tooling, in the fold area. And of course, it is very desirable to avoid cuts that run in the direction of the fold as these may well open up more, or even split entirely in time. Knowledgeable belt makers do not tool the bend for the buckle on a belt for the same reason.

Now as hopefully illustrated by the attached diagram, any fold, or even curve in the leather, creates a situation where the outer part is in tension, that is the fibers are being pulled apart.......while the inner part is in compression, the fibers are being pushed together. Any cuts, or stamp impressions,on the outside are going to spread apart....the degree of which depends on the severity of the curve or fold........ as well as the nature of the tooling.

Now, coming around to your sheath. As discussed above, rewetting of your tooled leather is going to diminish your tooling. This is even more problematic when you are bending, or moulding the leather. Remember....the outer surface is in tension on any curve,.....so not only is the tooling going to loose definition on the curve around the knife.....but also to some extent anywhere that you create a curve during your moulding process.

You might be wondering by now.....how do saddlemakers deal with this problem when it comes to saddles, particularly the very rounded areas of the swells? They do this by molding the leather to fit the swells first and then tool the leather in place. In one of of Al Stohlmans books on making cases, he shows this same technique used in making custom fitted rifle cases.

Can you use the same technique in making knife sheathes or gun holsters? Well sure, but it would have its own difficulties. That is why you don't see excessively moulded holsters with tooling very often.

[StrigaMort]

I'll have to take another browse at the Stohlman books.

Thanks for your explanation.

[WyomingSlick]

OOPS ! Forgot to attach diagram

[StrigaMort]

You explained it well with words, but I appreciate the diagram.