If the purose is to make SIPs or foam core panels, I made such things in the 1960s by creating a large very flat place (Nature really abhors a flat place) and laid down two sheets of luan plywood, coated them with (3M or other) solvent based contact cement, and one sheet of foam board , coated bothe sides with the water based (latex) contact cement. After surfaces were covered and thoroughly dry, with a friends help, and a jig made of 2x4s to keep two edges square and straight, we would lower the foam onto the first luan sheet and then the second luan sheet onto the foam. First with a rubber tire mallet, and then with two of us dancinging on the sandwich, carefully covering all areas, forced full contact. We used 2" extruded (the blue stuff) polysytene foam in 4x8 foot sheets. The luan was very thin (5/32") and cheap (then) paneling. The sandwiches were immediately usable, but gained strength over several days. They were more than strong enough to be used for the walls of a slide in pickup camper, which is what we made them for.
We made all the walls and roof, joining edges almost as they do today with sips. A piece of 3/8" steel banding strap bolted to the bars on a Weller gun type soldering iron easily removed the foam from 1 1/2" at the edges, allowing inserted 2 by lumber to be joined with other panels using tee-nuts and 1/4 x 20 flat head machine screws.
After nearly 50 years, I still have a desk made from two short filing cabinets and one of the experiments, and the remade support for the double bed in my small MH is another.
I only mention this here because I have seen (elsewhere) a long discussion about builder made sips and finicky nature of heat activated glue and the need for great pressure and very strong presses, etc, that were very discouraging to amateurs.
Of course, one might have some difficulty is getting such a construct past a building inspector, which is just as well. But, for partitions and non-load bearing walls, well...
Stan
Btw, I'm an owner builder anticipating finishing my home with a roof of 12" sips (just received the permit). |