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Ok here's my question I did my first carcass cast on a caribou and created my first mould out of fibreglass come out perfect "Using that word Loosely" but how do I find out how many pounds of part a and part b foam so I mix up to pour the mould. I know 50/50 of each but how do you come up with how many pounds? I know some people say 1/3 of the mould but I really what to find out how many pounds I don't want to blow up my mould
Thanks for your time any answers would be greatly appreciated.
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Jason , if your mixing 1/3 the amount of foam you will blew that mold apart . Your foam should expand 10 - 15 times its size or more . Start with a smaller amount , say about 16 ounces of each part and leave a small space at the back open. This way if you mix too much it will excape without breaking the mold and if not enough you can mix more and pour it in without removing the back board .You will have to do this until you can estimate what you will need on other molds . I'm sure someone on here has a formula to figure out how much you need . Rick
It takes a few to get it right. It is not an exact deal, but once you find out the amount, write it down on the mold.
I would use the 16 oz of each part and go from there. It should be close.
a similar size form, thats about how much foam you need. Tweak the amounts til it comes out right.
Fill your mould with water and weigh or mesure the water. Now, divide the weight of the water by the expansion rate of the material you are placing in the mold. I used to work in the mould lab of a furniture manufacturer. Our Urethane expanded by 300%. So if I was pouring a mould that needed 18 lbs of water to fill it, I would divide 18 by 3 and therefore, I would need to mix 6 lbs of urethane. Hope this helps. Duffy