In this instalment I cut and glue the foamcore boards. Read on to find out how I solved the issue of warping.
With the holes cut, I used masking tape to cover the exposed edges. You can’t spray undercoat onto exposed foam. There is something in the aerosol that eats and melts the foam. I’ve also kept the the pieces of foam core I cut out. I plan to place them back in the holes when it comes to spraying, but more on that in a future instalment.
Foamcore is an interesting product. It’s stiff and lightweight. It’s made of a thin sheet of foam bonded on both sides to sheets of cardboard. If one side is treated differently to the other side it warps. This could be due to moisture (glue) or heat. I’ve glued the top, cut layer onto the base layer. I used white PVA glue spread onto the board with a make shift spatula I made from an off-cut of foamcoam. I pressed the pieces together and instantly noticed the warping effect. So I “pre-tensioned” the back with masking tape. I then used a hairdryer on the back to try and warp it back the other way and it seems to have worked! Time will tell though.
The final shot in today’s post shows the raised areas glued in place and a unit of Big Uns placed into it’s slot. Also note I’ve used masking tape on the edge of the board as well. This is to neaten the edge and to help hold the boards flat while the glue dries.
Next time I start building the Fortress of Gork (or is that Mork).
Looking good. I give my pieces of foamcore a light coat of PVA and water on the side opposite where I'm painting etc. to reverse the warping. When it dries it will pull the board back to shape.
I'd guess the PVA glue is to blame. Lots of liquid in that glue. You might try a spray adhesive for your next outing
Brilliant idea! Cheers 🙂
Good luck! Foamcore warping is really tough to deal with. Why didn't you just use pink insolation foam. It's got no paper on it, so it doesn't warp.
Didn't have any and it's too thick. Plus I wasn't aware of foam core warping until I started. First time using such large areas of it.
Ah that's a neat trick, bracing the solid side.
Maybe a really thin cross brace and bracket with thin plasticard strips may also work?
Epoxy or uhu may be better than PVA for that step however ;).
Looking forward to seeing the next installments