Joining foam to wood roadbed

[Big_Boy_4005]

If you can, lap under the plywood for more bonding surface. That's what I plan to do.

[BR60103]

I have been using a couple of things.
I build up layers using Lepages green contact cement, the non-toxic type (I think it's #7).
I make other joints using Woodland Scenics Scenic Paste. This fills the gaps where things weren't cut perfevtly.
I suggest gluing a layer of foam to the underside of the roadbed and the forming the final surface around that. Maybe not a continuous layer -- just enough bits to hold up the scenery. Or extend the cleats under the roadbed to be wider than the roadbed.

[orsonroy]

QUOTE: Originally posted by aweinstock

Will these methods adequately affix the EDGE of the roadbed (1/2" plywood ) to the foam enough to stabilize it indefinitely? Thanks again for your responses.
a.weinstock

Possibly, but it won't stand up to a lot of abuse. Eventually, someone's going to apply pressure right at the joint, and the foam will break away.

It's too late to change it now, but I would have suggested using an all foam layout base to begin with, which would have been more structurally sound. Since you shouldn't rip up what you've already got, I'd suggest adding a plywood lip under the roadbed that the foam can rest on. That will add a lot more strength.

[CP5415]

I used foam friendly liquid nails then screwed it down using drywall screws with a variable speed drill for the first peice of foam. then liquid nails for each piece afterwards.
It is not going anywhere.
It would be better to have something underneath as well to a-fix the foam board to.
I attached it to the plywood on top of the benchwork where I am using the foam.

Gordon

[aweinstock]

Will these methods adequately affix the EDGE of the roadbed (1/2" plywood ) to the foam enough to stabilize it indefinitely? Thanks again for your responses.
a.weinstock

[Big_Boy_4005]

There are two types of Liquid Nails, one for foam is new and not the old standard. Water or latex based products work well, beware of solvents!!! I think Silicone is OK but is more expensive and stinky. White or yellow glues work well.

[orsonroy]

I'd personally add a few nails between the wood and the foam, to give it a bit of mechanical "grip". You'll still have to use some sort of adhesive, such as Liquid Nails, PL300, or wood glue.

Remember, Liquid nails recommends NOT using their adhesive to glue foam to foam! I use wood glue, which is cheap, strong, and available in one gallon jugs.

[Anonymous]

Liquid Nails or another latex silicone caulk adhesive. Works well for me, so far...

[aweinstock]

I am about to begin scenicking an open gridwork layout and intend to use laminated foam board. How do you recommend joining the built up foam to the edges of the plywood roadbed?
Thanks for your help.. Regards.
A. Weinstock