RTV not sticking to rubber

[prkaye]

I've foudn the red RTV does not stick very well to the black rubber baffling material. I need to seal up all along the top edges of the metal baffles where the rubber material is attached. Any tips for alternatives to the red RTV that will stick better here, and will withstand the temps? Proseal? Aluminum tape? Epoxy+filler? Other?

[Ironflight]

Hmmmm....I've got red RTV stuck to the rubber baffle seals that I put on before first flight, and it is still the Phil. Hard to remove as well. Are you sure the rubber is clean, and have you scuffed it up to give the surface a little bite?

I also used black RTV in places as well, and that held great as well.

Paul

[Neal@F14]

Like Paul suggested, you should try some of the Permatex "Ultra Black" RTV... the kind that does not smell like acetic acid, but smells like a solvent instead. It'll often stick to surfaces that the vinegar-smelling types of RTV won't stick to.

The Ultra Black has a temperature rating of 500 deg F, which ought to be good enough.

[erich weaver]

Just so Phil doesnt feel 'special', I have the same issue with my baffling material and the ultracopper RTV. I thought RTV stuck to everything virtually forever, but not to my baffles. Havent tried the black stuff yet.

erich

[Neal@F14]

The Ultra Copper and Ultra Black are very similar RTVs, so they probably stick about the same

[prkaye]

I'll try sanding my rubber a bit to scuff it. I hadn't thought of doing that.

[David Paule]

I've successfully used the red RTV to stick the red silicone baffling material to aluminum. I cleaned the surfaces well, first, and gave them plenty of time, in excess of a week, to cure.

Not exactly apples to apples but this worked.

[Lars]

Acetone, scuff, acetone. At least if it's silicone based baffle seal material. If neoprene, maybe not enough. Neoprene is a pain to bond.