I need to bond small pieces of 1/4” mdf to sheet metal (like an the steel on a car door underneath the trim panel. I’d like the glue to set quickly as clamping isn’t really possible. Further, I like the idea of something I can cut free with a razor should the need arise. The area will be subject to heat in excess of 120 and moisture in the air though no real water contact is expected.

Will a typical silicone caulk fit the bill?

Is this material going to be under any load or performing and structural duty? If so, then don't use silicon.

Scotchgrip 1300L will work, similar to weatherstripping adhesive. Prep and clean both surfaces thoroughly, then apply a light coat to both surfaces to be bonded. Let them set and dry over fifteen to twenty minutes, then press them together.

They can be separated by soaking with MEK or acetone, and gentle prying with a razor blade. A more permanent bond would be using epoxy. Clamping is not required or necessarily a good idea with the epoxy.

Go to 3M's site and look at their adhesive sealants.

Great adhesive mentioned above. 1300l will bond metal to neoprene rubber. Used this product in a machine shop for many years. If using a lot use adequate ventilation.

No load/structural strength required. It’s purpose is just to separate side a from side b so air can’t readily pass between.

I’d considered epoxy but the permanence of it gives me pause.

I believe contact cement would do what you want. Something like Barge. Apply a coat to each surface, let it have time to become tacky, then join the surfaces.

Really good buetal caulk that is used by roofers to secure flashing might be the ticket. the only problem is it takes a while for it to set (couple hours) but it stays plieable for just about forever. (sorry for the misspellings)

PR-1428 B2 is an aircraft low adhesion sealant that's designed for exactly what's described, and is removable and allows for panel separation. Slightly less expensive will be flamemaster CS3300 B2.

You If you're only trying to create an air barrier, then silicon will work for a period of time. It will shrink and change dimension, over time.

Adhesives aside, MDF doesn't do well with moisture.

quote:

Originally posted by arfmel:
Something like Barge.

Barge will stick just about anything, to just about anything else. I learned about it from local saddlemakers, where it is used extensively. I've used it for neoprene to stainless steel, leather to stainless steel, and neoprene to wood, to name a few uses. Just make sure you get the yellow can, not the blue. The blue is the newer OSHA-and-every-other-agency approved "safe" version. IOW, the blue can has all the good stuff removed.
 

how about using 3M VHB double sided Foam adhesive tape like that used to hold trim on?

Maybe just calk the gap if it’s only 1/4 inch.
Maybe some double stick tape, less mess than glue.

Some form of Double sided tape / Pressure sensitize adhesive would work and set quickly.

Flex Seal?? Stuff really does work well. Might break down after a few years, is that an issue

quote:

Originally posted by 220-9er:
Adhesives aside, MDF doesn't do well with moisture.

Yes, I was pondering this over the course of the morning. I think it’d be ok as we are a real low moisture environment but I’m kicking around the idea of using ABS plastic or even kydex now.

Does that change adhesive selections that have been recommended?

Come to think of it I have some of this stuff lying around... think that’ll do if I go with the abs?

Double-Sided Acrylic Adhesive Strip for Vinyl, 50-Feet https://www.amazon.com/dp/B002..._api_i_gIZaBbK61SWSV

Red Loctite?

3M VHB, rock solid stuff.
https://www.amazon.com/3M-Tape...-Sizes/dp/B00K2N2JLI

What are you using it for?

Butyl tape is probably your best best. That's what's comongly used in automotive applications to help seal up things and bond vapor barriers etc to things.

3m 4200. It’s sold at most marine stores and some Lowe’s type places. 5200 is definitely sold at he Lowe’s and a stronger adhesive than 4200, but tough stuff to saw off to remove things.