Adhesive for rubber to metal?

[LittleSister]

What would be the best glue, and any specific preparation, to firmly attach rubber to metal?

I previously tried epoxy after the original adhesive had failed (after some years' use), but my repair didn't last long.

The pieces in question are kayak footrests, which should be glued to metal pegs (these slide in tracks providing fore and aft - i.e. leg length - adjustment). The footrests themselves comprise a rigid plate which the foot rests against, and this plate needs to flex around the vertical (a) for comfort/efficiency, and (b) because they are potentially also used (though not currently on my kayak) to control a rudder via cables. At the back of the foot plate (forward in the boat) is a rubber block (this remains attached to the plate) which provides for this flexing, and which is (or was!) glued to the metal pegs.

I can't remember just now whether the mounting pegs are stainless steel or (more likely) aluminium. I don't know whether the rubber is natural or nitrile (nor how to test to check) if this makes any difference.

 

[wallacebob]

Superglue is excellent on rubber, needed damp to set it, but I think a roughen metal surface with contact adhesive on both surfaces may be best. Clamp overnight.

 

[Chiara’s slave]

Epoxy does not adhere well to metal. Polyester resin is better, but probably not with rubber. My bet would be Sika 291. I haven’t tried superglue though. That might well be worth a shot.

 

[RivalRedwing]

forgive the brand name 'Evostick' or similar was our glue of choice, but it will not last for ever.

 

[Daydream believer]

Epoxy does not adhere well to metal. Polyester resin is better, but probably not with rubber. My bet would be Sika 291. I haven’t tried superglue though. That might well be worth a shot.

One would need a lot of superglue & a very clean metal surface
Trouble with Sika is that you need a thickness. If you squeeze it right out it does not work- At least that is what I found. so with rubber you may end up with an uneven surface due to uneven thicknesses of adhesive.
Personally I would research one of the Bostic contact adhesives that are waterproof. Evostic is not, so would not last so long.

 

[Fr J Hackett]

Sticking rubber to metal is difficult you either have to go to a mechanical bond or a chemical one. The chemical one is complicated and requires pre treatment of the metal surface and usually an intermediate product that will bond to both the metal and rubber. The mechanical bond is determined by the quality of/ condition of the surface of the metal.

 

[Stemar]

The mechanical bond is determined by the quality of/ condition of the surface of the metal.

Which basically means clean and well scratched with about 80 grade abrasive paper.

As for the glue, I've had some success with contact adhesive, but the unkind stuff that doesn't allow repositioning.

 

[wrr]

Two-part Bostik 2404 is superior to contact adhesives and should do the job, with appropriate surface preparation as above. Small tins are available.

 

[ylop]

Superglue is excellent on rubber, needed damp to set it, but I think a roughen metal surface with contact adhesive on both surfaces may be best. Clamp overnight.

Superglue do a gel based product (power gel?) which the specifically promote for applications that need some flex. I've only used it once but it seems to live up to its claims.

 

[PCUK]

As with everything. CT1! Roughen both surfaces first.

 

[Ian_Edwards]

I'd be tempted to try CT1 or OB1.
I've glued nitrile rubber sheet to A4 stainless steel with OB1. It was difficult to remove the nitrile sheet several years later.
I was eventually able to peel it of, but had to use a rotary wire brush to remove the OB1 from the SS.

 

[RogerJolly]

Epoxy does not adhere well to metal. Polyester resin is better, but probably not with rubber. My bet would be Sika 291. I haven’t tried superglue though. That might well be worth a shot.

Is this true? Araldite (eg) lists metal as first thing it sticks.

 

[Hacker]

Did you never see the advert where they glue a crane hook to the top of a mini?

 

[Stemar]

Is this true? Araldite (eg) lists metal as first thing it sticks.

It'll stick well enough, but it epoxies tend to be rigid(=brittle), so may not cope well with thermal expansion and contraction.

 

[vyv_cox]

I am not sure about this application but for engine mounts the rubber and steel are assembled prior to the vulcanisation process. There is no adhesive involved.

 

[Fr J Hackett]

I am not sure about this application but for engine mounts the rubber and steel are assembled prior to the vulcanisation process. There is no adhesive involved.

I would guess that the steel is treated with an agent that adhere to the steel chemically and links to the rubber during vulcanisation.

 

[Chiara’s slave]

Is this true? Araldite (eg) lists metal as first thing it sticks.

It definitely is with respect to cast iron. Epoxy on my XOD keel will fall off in a season or 2. Polyester resin first improves the life by 200% at least. This is significant, in the X class, if you don’t test the bottom for firmness every so often, you won’t be winning much.