Has anyone blown their own PVC foam?

I have read and studied boat building for many years, I now have the oportunity to start building soon. I recall reading about the ease of gas propelling a resin through a nozzle and shooting your own closed cell extruded foam. Now I want to be able to fill the frame-bays of an aluminum boat hull with foam and seal it in with another sheet, thus making a foam-core construction (and all of it's inherent benefits: thermal insulation, sound deadening, structural strength, etc).
But I can not seem to find any current source for do-it-yourself foam.

Has any done this themselves before? or, does anyone have any assistance?

 

spray foam sources

check this web site out

http://fomo.com/about.html/fomo.com

 

Hope you're gone glue that last sheet! Be very carefull with welding as your boat might go up in smoke (some foams are combustible), or you don't live to tell!(some foams produce a toxic gas when heated or burning)