What kind of glue won't attack foam?

Just wondering if anyone is schooled in adhesives? I need some sort of glue that won't attack the foam board that we have discussed in the post on tonneau covers.

 

i think they use some spray glues on foam at the upolstry shops...maybe fatluckys knows

 

i know...i spelled it wrong

 

I know it can't have MEK, Methyl Ethyl Ketone, in it.

 

3m super 77 should do the trick. spray the foam AND the material, let set up for a sec or two, then stick 'em together. kinda like rubber cement. make SURE you have the position you want before stickin' it, cuz it'll be stuck.

anything better/easier/cheaper/more durable anybody?

 

From a thread awhile back from badpat.
www.thistothat.com
Shows what to use to glue anything to anything.
George

 

If you use a urethane base foam (or epoxy, rare) instead of the styrene base foam you won't be dissolving it with the glues or resins.

 

Root-

I meant to reply to this earlier this morning, but I got caught up with work (geez..)

For my senior design project, I helped design a racecar. We used the pink insulation foam that you're talking about to build a mold/core for our nose. First, we stacked up four layers using 3M spray adhesive to hold them together. Next, we cut it to shape using a coping saw and smoothed it using sandpaper. Well, I shouldn't say smooth -- the foam came off in little chunks, not at all like sanding paint or bondo. Lastly, we slathered the core with release agent and 'glassed it.

It looked like hell and I wouldn't recommend this method for building a nose for your racecar.



However, 3M spray adhesive and a coping saw should work for what you need.



Ed

 

That's a pretty neat site....

 

simple old elmers works fine..

 

[ QUOTE ]
If you use a urethane base foam (or epoxy, rare) instead of the styrene base foam you won't be dissolving it with the glues or resins.

[/ QUOTE ]

This is the key, Roothawg. You're using the wrong foam. Polystyrene will get eaten, not only by the glue you're using to stick it together, but also by any resins, like ones you'd use in fiberglassing.

Polyurethane foam is what you want to use. It comes in sheets, and also in aerosols, as in the expanding foam used for home insulation. The expanding foam is great for filling in volume, but it's hard to get consistant sized cells once it dries: the foam is much more dense near the surface when it cures, and a lot less dense in the center. It's harder to work with, but it's a lot cheaper than buying polyurethane sheets.

--Matt

 

I am assuming that you would have to go to a specialty vendor for polyurethane sheets? I just need one sheet. The bed is approx. 46x70.

 

Here's the trick to glassing pink foam. Get it to the rough shape you want, then cover it with plaster or spackle. Sand to final shape, paint with lots of think coats and wax really good. Works like a charm. We made a 6 foot diameter 'glass sphere this way back in my college days.

-Bugman Jeff

 

You can get the expanding stuff at Home Depot or wherever, but yes, the sheet stuff is harder to get.

It's available in various thicknesses at www.mcmaster.com. A 1" by 24" by 72" sheet is under $30, but I don't know how much shipping will be. Sheets may also be available at boating supply houses, or anywhere else that fiberglass products are sold.

That foam WILL stand up to MEK.

 

Also to make a polyurethane sheet, couldn't you make a 2x4 and plywood form and fill it with the afore mentioned Great Stuff expanding a foam in a can and level it? Might be to much work for the cost of just buying a sheet.

 

I use SUPER77 alot, workes great on foam......it's made by 3M.......sprays on, very easy to use.....

CT.

 

If you find urethane foam in a building supply (or anywhere) it's probably going to be yellow in color and will get darker yellow if exposed to sun. (suntan foam?) It's also the stuff surfboards are made of. The oldest maker of surfboard blank foam around is Clark Foam http://www.clarkfoam.net/ check them out for a theatre near you