Structural foam resin alotment

General Composites Discussions Composites Talk
#1

I had this question on another thread, but it wasn’t part of the thread title, so I figured I’d start a new one.

I was looking at using the Divinymat for sandwiching a part with infusion. It says it is made for both infusion and sandwiching, so I called Fibreglast to find out if one, it needed to be between two layers of reinforcement or just on the inside layer only, and two, how much resin needed to be added to the infusion resin source. They didn’t have any answers.

So, do you think it needs to be between layers of reinforcement? With the backing of the Divinymat, I’m not sure resin would even get to the backing cloth, but I’ve never used it so I don’t know.

How much resin needs to be added to the source container?

Thanks!

EDIT: Oh, one other thing. They sell 1/8" green foam at Lowes in 4X8 sheets. I wonder if you could use some thin cloth and 3M spray adhesive and make your own. Once you’ve got the backing on, get the razor knife out and start cutting slits. I’m using Epoxy resin, so I think the green foam would be safe. Thoughts?

#2

Do a search on the datasheet of “green foam” and divinycell. (especially shear strenth and modulus) and you learn why it is not used much in composites.

Small blocked PVC foam will eat a reasonable amount of resin. I have no figures, but expect 2 lbs of extra resin per sqyrd. Perhaps more.

Oh, and core materials Always need to be in between layers of glass. Without doing any calculation, keep glass thickness at about 1/10 of the core thickness. Nice figure to start with.