Where can you get silicone gel that can be easily molded that does not degrade over time?

I need some kind of gel padding for an underlayment on a suit of non-ballistics body armor I am building. What I want is some kind of mixture I can mix up, dump in a shallow mold, let it cure, then pull it out and cut it to shape and put it in the suit. Preferably this gel would be pretty good at absorbing shock and would not degrade over time if kept in a sealed environment away from sunlight, like sealed in a plate in the suit. 

Anyone know of anything like that that is easily available and not over priced? I noticed the silicone used to make molds for casting, would that work? My friend suggested ballistics gel but it seems like it would degrade over time. 

Any suggestions would be greatly appreciated. 

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I would use a mixture of oogoo and styrofoam beads at  around a 2:1 ratio by volume. Make small test pieces at target thickness and tailor your ratio of cornstarch to desired hardness. You can use dirt cheap molding silicone for this to cut down your costs substantially over more exotic compounds.

The styrofoam beads will have three benefits:
  1. Reduce your cost with a cheap bulk filler.
  2. Decrease weight with effective air voids via beads.
  3. Reduce resonance from impact.
~3: In physics heterogenous mixtures do an amazing job of slowing the transmission of just about anything (heat, vibration, light, etc). When the impact vibrations pass from silicone to bead to foam again, their different resonant frequencies will create a huge transmission loss and dispersion on energy. This will give a significant reduction in the shock or vibration transmitted, even relative to homogenous materials with superior qualities and price tags.

James Schlitt
ilpug (author)  Punk Love Designs5 years ago
better late than never, this sounds really freaking useful, I will most definitely try this.
canucksgirl5 years ago
What you're looking for is a product like Perma Gel. It'll do everything you're asking, and doesn't decompose like ballistics gel (because it isn't a gelatinous substance), BUT, it's rather expensive. It's also rather heavy (like ballistics gel).

What I would suggest you do instead, is use an "expanding foam" (spray foam insulation). It's light weight, strong, less expensive, moldable and cut-able. It's like styrofoam after it dries. I would think it would work rather well as a shock absorber, because they use styrofoam substances to protect packages etc. You can buy the stuff in spray bottles (or in larger volumes). Just make sure your mold is either lined or greased (so you can get the foam out in one piece). It also comes in low and high expanding formulas, so check before purchase.

If you have any questions, let me know.
ilpug (author)  canucksgirl5 years ago
I was considering that... I will have to try that out, i have some around.
So... did it work?
ilpug (author)  canucksgirl5 years ago
Kinda, but once it was indented it didn't recover. It had very little impact absorption. instead, I bought some Sorbothane sheets.
Thrasym5 years ago
What about just strait silicone sealant, caulking, etc? You know, the big tubes of stuff in the hardware stores. It would need to be layered up, allowing each layer to dry before doing the next if you're doing anything thicker than 1/4" or 1/2" I'd think. But it's available just about everywhere and it's fairly cheap.
Honus5 years ago
Smooth On has several products that would fit your needs. I'd probably use Flexfoam-iT! flexible urethane foam or Soma Foama flexible silicone foam.

You might try a Heavy Gel Medium Made by Golden - it takes a while to set up, but they make several consistencies, some with additives like pumice may be more moldable than others.

you can try mix styrofoam with acetone. it results in a cheap, moldable plastic that hardens in about 1 day.
ilpug (author)  tgferreira1845 years ago
Huh, I actually need a softer material, more like a shock absorbing gel.
you can try mix styrofoam with acetone. it results in a cheap plastic (polystyrene), that can be easily molded, doesn't degradable and that hardens in 1 day
kill-a-watt5 years ago

ilpug (author)  kill-a-watt5 years ago
Huh, I forgot all about oogoo. I would need a lot of it, but I suppose it would do the job. I must try this!