Leather Breastplate Questions

[Drystan Gwalchmai]

So I'm in the process of piecing a leather breastplate desing just for the fun of it. Now, my goal is to make this practical, not fantasy-based. I've got a two piece design that I'm drawing up and hopefully I should have something resembling a prototype by the end of the week. Seeing as I've never done one before, any suggestions on design and/or functionality that would be taken in to consideration? Or any particular weight/type of leather to use on this?

[Johann ColdIron]

The problem is we really do not have that many historic examples of leather breast plates. Arrows, quarrels, and gunfire limited its popularity. Time ravaged the rest...

That said I have made one out of Sole Bend patterned after a late period peascod and covered it in velvet for SCA armoured combat. the front was two piece, stitched up the center with a scallop out of the lower seam to get the point to look OK. The back was a short rectangle tucked under the wings of the BP. Not period in the least but worked well for SCA.

It held up well as long as it was allowed to dry between extended use. I got a separated rib from a spear thrust to the back plate. The leather was floppy from a week of fighting at Pennsic. I suspect the foam of the spear was also dead.

I used the heaviest sole bend leather I could find. Also search under "waterharden leather" here to find more about techniques. You might get by with thinner if properly hardened.

Or make a steel one. In this century steel is cheaper that good quality leather.

[Atlanta Armory]

It depends on what you're designing it to do. Even if you're just doing it for fun, try making it meet the needs of someone out there. You can sell it, make another one a little more refined. Rinse. Repeat.

For most groups, the absolute minimum thickness is 11 ounces. I'd recommend 13oz (it'll come in hides 13-15oz typically).

For design, I'd look in the Patterns area, and pick one that resembles what you want. Compare it to others and see what they all have in common, especially in the shoulder and neck area. You'll have a tendency to make the shoulders too wide (restricting arm movement), the armpits to high (can't lower arms comfortably), and the bottom edge too low (every time you lean forward the neck part slams into your throat). I'd take a look at this pattern and use it for the shoulders: http://www.armourarchive.org/patterns/g ... t_rainald/. Just keep in mind that it is intended for metal, and is intended to be dished, so some of the lines come out curved. The good thing about leather is that you can easily trim to fit for small problems.

I'd also consider hardening it, which can be tricky depending on the method you use:

Water Hardening - Immerse pre-wetted leather for 20-60 seconds in 170-190 degree water. Stay below 180 for larger items and make test samples to figure out the combination that gives you what you want.

Glue Hardening - Mix an animal based glue (resins can be used as well, but I'd avoid them until you've got more experience) with water, about 10 parts water to 1 part glue. Mix thoroughly and immerse the dry leather item for about a day to guarantee full penetration (giggity). Let dry for a couple of days. You can use a heat source to make it dry and cure faster, but stay below 120 degrees F or else you'll water harden the leather as well, which will make it very brittle.

Wax Hardening - This is probably the easiest and most forgiving of the methods. There are different recipes you can use, but I'd recommend using a wax that melts below 170 degrees to keep from overheating the leather. Take your wax, heat it until it melts (and keep it only a few degrees above melting point), and immerse the leather into it. Keep it there until most of the bubbles stop coming out. You can shape your piece once you take it out, but it can lose this shape if exposed to high heat. The famous example is in the trunk of a car. You can avoid this by first working the leather when it's wet and heating it just a little (maybe 150 degrees, if that) to get the final shape you would like. Let it dry completely before using the wax. Be careful using this method, as some wax vapors are toxic or highly combustible (or explosive).

For your needs, I'd say that glue hardening is probably the easiest to use for an item that sized. Use Titebond glue or some other similar glue (I think Elmers works as well). I'm fairly new to leather, so I may be corrected in some of the points above.

-Ben

[Arrakis]

You can also bake harden leather, where you soak the leather in room temperature or cold water, then bake it in a 170-180°F oven, shaping at regular intervals (every 15-20 minutes) until it is dry/done (multiple hours).

[Atlanta Armory]

Forgot about that one. It's basically the same thing going on, but you have more time to work with it. If you don't mind it taking a while, you can cook at a lower temperature to lessen shrinkage. If you have a durable manaqiin chest or some similar form, you can stretch the leather over it as it cooks

[Arrakis]

I've never actually had anything shrink appreciably with that method. I may have gotten just a bit, but it would have to have been on the order of millimeters.

Good luck, OP.

[Drystan Gwalchmai]

I've done a gorget before with the wetting and baking method, and like Arrakis said, there really wasn't any shrinkage. Mind you, this was only 5-6 oz leather. So with using heavier leather, I don't see the possibility of any shrinkage at all. I'll also have to get a mannequin or armor dummy in the making as well. I'm sure it'd beat using my own form to mold everything!

[Atlanta Armory]

With heating rather than immersing in hot water, the heat flow into the leather is much slower, and since you're fiddling with it fairly often, you don't really give it much of a chance to shrink / thicken. Now that I think about it, its probably the superior method for larger items, which are going to take a while anyways.

-Ben