Need a good spalling test methodology

[Chatterbox]

I've just ordered the following:
-AR500 10x12inch curved trauma plate
-9mil security laminate film (5feet x 1 feet)

I'd like to test various spalling scenarios. My hope is that the security film, when applied to the front of the plate, would contain any fragments. However, I could use some help with devising an appropriate test. Preferably, it should be one which allows me to measure the effect of various thicknesses of film.

[HelmandHunter]

My interest has been peaked

[Aries144]

A simple 'test' I've performed is to strap/tape the plate to something like a sandbag and put a cardboard box over it. This will enable you to see the direction of splatter and determine for yourself if your catchment material is performing.

[robfromsc]

I've got a set of those plates that I coated with linex. Thick! Haven't tested yet, but was planning on putting it in a shoe box, saturated with water. The wet cardboard would be very soft and soft tissue like.

Not very scientific, but I'm not a scientist

[Aries144]

I think you might be over-thinking it. There's really no need to consider tissue simulant for this sort of an experiment. All you need to do is determine whether or not the fragments are being captured. If some splatter is escaping and making holes and tears in the cardboard on the top, bottom, left or right sides, it isn't working and needs improvement or a different catchment method.

[Clint]

Cardboard or 1/4" plywood would work good.

Most of the spall should be parallel with the face of the plate.

Good idea for testing.

[robfromsc]

K29 can be bought for about 60-70 bucks that would definitely do the job. The linex was free. And before someone says it, yes the linex wont stop multiple and repeated hits.

[Chatterbox]

Thanks, I'll try out the box idea. Now, what was that about K29? What is that?

[robfromsc]

Thanks, I'll try out the box idea. Now, what was that about K29? What is that?

http://armorco.com/shop/category.aspx?catid=2

[AndrewWiggin]

This has been studied in detail on that other site. I don't know if I'm allowed to link there. The bottom line is that 3-5 layers of Kevlar attached by nothing but Gorilla Glue stops frag from 2 or 3 shots of 5.56mm and Herculiner (not Duplicolor, that stuff is pure shit) applied in multiple coats to around 3/4" or so will stop frag from at least a dozen rounds of 5.56mm. The best solution is probably going to be 3-5 layers of Kevlar adhered to the plate by Herculiner and with a layer of Herc between each layer of Kevlar and several coats of Herc on the outside. The Kevlar should wrap around the back of the plate by just a bit to provide a sort of pocket to catch any frag that might make it out, especially for hits very close to the edge of the plate. Proper surface prep is critical.

Fragments are enough to cause very painful injuries at the least but because they come out over 360 degrees, there is a significant chance that they may perforate the brachial, femoral, or carotid arteries. Fragments from larger, slower projectiles (i.e. 7.62x39mm) tend to be larger and slower and penetrate much deeper than fragments from small, fast projectiles (i.e. 5.56mm). Either will shred a PC and present serious injury risk.


After careful consideration of the threats you consider likely, you may consider true spall protection, which is accomplished by wearing soft armor BEHIND the plate. Spall is composed of steel fragments that come off the back of the plate. Fragmentation is what we call the bits of lead and copper that break apart on impact.

It may also be a good idea to wear soft armor behind the plate in the hopes of catching a high speed bullet such as M193 that has defeated the plate. I'd like to hear from the experts on whether soft armor has much chance of stopping this sort of thing.