Bruce, it is all foam.
Warping is a two fold problem.
a. the entire structure needs a coat of primer from the rattle can because the following paint is water based and would warp it like crazy. I had that problem with the left invisible wall of the ice storage. Saved the primer from the rattle can but painted it. I had the cut the wall out next morning and insert a nw one.
b. The ice storage is made of very thick material and has no extra enforcement. The new building is much more fragile due to all the windows and the grid design. I am just at this moment glueing the parts together (wall are done, roof is setting) and add enforcement from the inside.
The last four "shoe box" buildings have a roof of 1cm thick foam core. That kind of roof is very stable and the 3mm walls rely on the roof. The new building has a 3mm roof (less space over the top window row) and that needs extra support too.
Warping is a two fold problem.
a. the entire structure needs a coat of primer from the rattle can because the following paint is water based and would warp it like crazy. I had that problem with the left invisible wall of the ice storage. Saved the primer from the rattle can but painted it. I had the cut the wall out next morning and insert a nw one.
b. The ice storage is made of very thick material and has no extra enforcement. The new building is much more fragile due to all the windows and the grid design. I am just at this moment glueing the parts together (wall are done, roof is setting) and add enforcement from the inside.
The last four "shoe box" buildings have a roof of 1cm thick foam core. That kind of roof is very stable and the 3mm walls rely on the roof. The new building has a 3mm roof (less space over the top window row) and that needs extra support too.
Reinhard