Foam glue

[Chris333]

Stacking foam sheets for scenery and using Titebond ultimate wood glue. It takes forever to fully cure.  Is there a such thing as instant super glue for foam?

[MK]

Yes!  Look for foam safe CA at R/C hobby stores.  They are also, usually but not always, odor free so if you see odor free, check for foam safe too.  They are not cheap so hopefully you are only gluing small pieces of foam and not 4x8 sheets. 

Bond is instant

[Chris333]

So it works?

Damn looks like $90 bucks for a man sized bottle.

[thomasjmdavis]

I generally opt for foam adhesive (construction adhesive in a tube, formulated for installing foam insulation- ie: "foam sheets") over Titebond.  It won't cure immediately, but will hold foam in place until it does cure. Available at most home centers or hardware stores.

For small bits, I use Alene's tacky glue (Walmart or Hobby Lobby).  Again, it does not cure immediately, but it lives up to its name- it is "tacky" and holds well from the moment you put pieces together.  It also stays tacky as it dries (at least initially, until dust in the air gets stuck to it), and you can sometimes use it like contact cement on small parts.

And then, there are contact cements that are foam-safe.  Back in the days when I was building stage sets and displays, that is what we used on large panels.  The downside (as with "instant" glues) is that once it is stuck together, it is stuck together, and the bond may be stronger than the material- so no second chances.

[Chris333]

Just running into the thing where you have a stack of foam you cut into and find all the glue on the inside is still wet because there is no air in there.

Also after gluing you need to clamp or weigh down the sheets. I just want to start carving up the foam and have no time to wait all day (or longer) for glue to dry.

[MK]

So it works?

Damn looks like $90 bucks for a man sized bottle.

Yes, it works.  We build big R/C airplanes with it.  I warned you it was expensive.    But if you are gluing pieces for mountains, etc., you don't need to coat the entire piece with the glue.  A few lines in strategic spots will do.  It is very strong (big airplanes don't fall apart in the sky ).

[Chris333]

I buy my regular ACC in 16oz bottles that I keep in the fridge. I use it to refill smaller bottles.

My 16oz Titebond I bought yesterday is half gone. Now I did use way more than I needed. But would like foam safe ACC in a 16oz bottle.

[Chris333]

Looks like "foam safe" means that it has no solvent in it. I'd guess the solvent is what makes superglue dry so quickly. So how does foam safe superglue even work?

[wazzou]

I always used Liquid Nails.  They have a foam version.

[davefoxx]

Looks like "foam safe" means that it has no solvent in it. I'd guess the solvent is what makes superglue dry so quickly. So how does foam safe superglue even work?

I don’t know that, but I do know this. I once spilled a bottle of Testor’s Liquid Plastic Cement on my layout.  It literally ate a cavern into the 2” foam!

DFF

[mkearns]

If you want strong and instant, consider wood screws. Especially for holding multiple layers together. Think through the placement so as not to limit future carving or inserting things like trees. Only takes a few though. And could always glue on the final top layer. I use Loctite Power grab.

[C855B]

I don’t know that, but I do know this. I once spilled a bottle of Testor’s Liquid Plastic Cement on my layout.  It literally ate a cavern into the 2” foam!

Some spray paints will do this! I had to carve away an embankment after a quick spritz with a texture paint. Glanced away and then looked back, "Ohmygawd, make it stop! STOP!"

I had to cut out a big chunk. ...sigh... Always test first, always test.

If you want strong and instant, consider wood screws. ... I use Loctite Power grab.

I can't get with screws. Not if you plan on carving anything. If I need mechanical fastening, I use wooden shish kabob skewers placed at opposing angles. Still not good for carving, but at least they won't screw-up your tools if you hit one. For glue, I was using Glidden Gripper, but that will not cure unless exposed to air. Loctite PL300 (foam compatible) is my go-to these days, but it's not instant, not by any means.

[MK]

Looks like "foam safe" means that it has no solvent in it. I'd guess the solvent is what makes superglue dry so quickly. So how does foam safe superglue even work?

It's not the CA solvent but the CA fumes that will eat the foam.  So making it odorless means no fumes which means no attacking foam.

[wazzou]

*** Edit to my original response. 
Liquid Nails for projects. 
Pressure and time, like Red says in Shawshank Redemption.

[GaryHinshaw]

I may eventually regret this, but I just use hot glue: a Stanley glue gun on the low setting.  I sets almost instantly and so far (over 5+ years) it has held up just fine, even on sections that are still just resting in place and subject to some modest handling.  I wouldn't necessarily recommend it for a portable layout, but it has been fine for a home layout like mine.

When I attach a big chunk of laminated, carved foam to the benchwork and fascia I have been using Flex Paste, which is a bit of a pain to work with, but makes an excellent bond and fills gaps very nicely.