Pourable foam, need advice

I have a couple of questions about pourable foam. I have a fish box that I need to insulate. The bottom of the fish box is about 2 inches off of the existing foam in the boat. I want to fill in this void. I know the foam expands quite a bit. Can I pour the foam in the bottom and then install the bottom of the fish box before it sets? Or, should I pour the foam and trim off the excess?
I am also pouring the foam around the exterior of the box. I need to build a form around it to give me about 2 inches of foam. What will allow me to release the form from the foam?
Thanks for your help.

 

From my limited experience with A/B foam.

I have used both the 4 and 8 lb/ft densities. I have had successful castings using plastic film as a release .

Plunking the bottom of the box over the liquid foam just after you mix, pour, spread it, should work .... if you didn't get too much liquid foam poured in.

mix it quickly and spread it out into the corners to avoid voids.

 

If the box is already built, you can hang it of a couple of pieces of angle iron via clamps. Get it right where you want it and clamp it all down good cause the foam will push the box up otherwise. After it's all ready, pour in the foam. Cut excess off later.

 

Remember the key here, don't use too much foam. It can develop quite a push on a big panel if confined. Fortunately the new foam can compress the old foam a little too.

 

you shouldn't have too much a problem with push, considering you will have around 2 inches of space all the way around the box. that's plenty of room for the foam to expand out of. just keep i think i would opt for the, 'pour the foam with the box in place method". maybe figure the volume of the bottom and mix an appropriate amount to fill that, let it cure, then mix for the sides. you should be able to watch how much you need to pour by working around the box in "lifts" .

 

Where do I get pourable foam?
I have a 73 Glastron that has waterlooged foam. It should be closed cell, but I think it's broken down over the years. So... I need new foam!
Any suggestions?

 

Here you go, good price, and quick shipment:
http://www.uscomposites.com/foam.html