I cut my foam today and the joints don’t quite line up. Must be I didn’t make square cuts and have gaps up to quarter inch.
What’s a good gap filler for foam? (I’m using pink extruded 1" thick)
Thanks!
I used Red Devil joint compound with good results.
I use lightweight joint compound which is what JCasey is probably talking about also. It is at any hardware like Lowes. It appears to be the same stuff that Woodland Scenics sells in a very small container. The good part is that the big tub at the hardware costs about the same as the small container at the hobby shop
Paul
Dayton and Mad River
Ditto. I have a 5-gal tub of lightweight joint compound from HD. Used about 3 gal of it for a drywalling project, and dip into the remainder for filling foam joints.
If you’re filling 1/4" cracks, I’d suggest using some kind of filler - 1/4" is right about the point where joint compound alone starts to have cracking/shrinking issues. No big deal, though. Just shave off some foam and shove in there. Little bits of wadded up newspaper would work too (what I used when I had a bigger opening in aforementioned drywall project - worked fine).
Try some foam in a can, such as Great Stuff. Be careful not to use too much as it does expand quite a bit. When it sets up you can trim it off flush with your foam.
I use non-shrink spackle for smaller gaps (1/4" and under), and for larger one (over 1/4") some foam slivers. And I skim coat everything with drywall mud.
Nick
Lightweight acrylic spackling compound works great. It sticks to the foam and has about the same resiliancy and consistency as the foam itself.
I cover the joints in my foam with plaster cloth. I use a thin coat of plaster anyway, but the plaster cloth makes for a seamless joint.
I assume you do this after laying the roadbed. Correct?
I avoid plaster and joint compound, but that is a personal choice. I use Sculptamold to cover the foam and fill any joints. It is a paper mache product with some plaster mixed in to give it hardness, but it dries lighter-weight than plaster alone. I like it for sculpting rock faces, too. If you decide to change something, just wet it and take it out after a few minutes.
The scenery will cover them anyway , so why be so concerned. The only place would be where track/roadbed will be. If your gaps are much too wide for your liking, just liquid nail some foam strips or slivers into the gap. There seems to be a great concern about having this absolute perfectly flat deck to lay the track on, I don’t understand this. It is suitable for yards to be flat, but not the entire layout. Hills, dips, rivers and all other scenery that will make a great layout is far from flat. Even a dessert has some relief and dry washes.
Bob K.
I used clear silicone to fill gaps.
Mike P