Jesmonite

[Tahu]

Hey all!



Ive ordered some Jesmonite to try it out. I have been speaking alot to a person that is working on a big company in Scandinavia about their "own mixed" Jesmonite" that they are sellling.



Normal Polyester Resin weighs 1,1 kilo / liter, Jesmonite 1,9 kilo / liter.



I have my Master Chief helmet that now, with 2 layers of normal Polyester Resin and fiberglass all over the inside, weighs 480 gram, and its hard.



And then I accidently poured too much resin into just one spot, so I could even minimize that. And those 480 grams is without Bondo.



According to my calculations, you could take 480 x 1,72 to get what weight it would have been if you used the same amount in Jesmonite. The result is 825,6 grams.



I wont be molding with Jesmonite, I will be applying it to a Pepakura model, and the paper will suck up the Jesmonite. I dont know how much Bondo

you will have to use to make it, but say that you use a 1/3 of a one kilo can, thats about 300 gram (because you sand alot away), the final weight

would be 1,1 kilo (825 + 300 - 25 (Minus 25 because I accidently poured to much resin in my last MS helmet on just one spot)).



And finally, 1,1 kilo isnt too much for a helmet though? I am thinking that you could try to sand quite some off the Jesmonite and reinforce with Bondo instead. And if I need to, I can mix my own FiberBondo to reinforce instead of using more Jesmonite. I think that Molds weigh more than pep based armor, but you are the one who have tested it, not me.



I will post my results on the 405th for everyone to see, and learn. When I am going to make molds, I will follow your advice and use something else.



All the best!

/Tahu

[XRobots]

I thought some people may be interested to see a large Jesmonite cast I've just completed. It's the first part of a Giger Alien head which is almost a metre long and weighs in at just under 4Kg. This is laminated with Jesmonite, surface tissue and Quadaxial mat. The full construction WIP can be seen here: http://www.xrobots.co.uk/alien/index_head.html



I guess for something like a normal helmet you should be able to achieve it in less than half the weight.

[Broz]

Based on those tests it looks far too brittle. I have an Army of Two mask made of resin and fibre glass mat and it has easily taken close range bb strikes, been fallen on, crashed into trees and taken a hell of a lot of larp weapon strikes (not to mention less than gentle treatment in transport over more than ten thousand miles.) I not convinced Jesmonite can take that and remain pristine, it strikes me as depending on how desposable you regard your armour.

[Tahu]

Well, I bought a couple of kilos of Jesmonite, and I can only say Broz, it is far from brittle. Jesmonite can handle smashes as well as frost. lol, you can even mix it with stone filler to get a kind of cement. Seeing how toxic normal resin is, and experiencing it, I am not sure I wanna walk that road again, not when the difference is so small.