Bonding Polyurethane Rubber to steel

[Shox Dr]

Any suggestion on what to use on steel to get a better bond with PU rubber.

Ive spoken to the suppliers and they have suggested either a Zylene prewash or Shellac.

One thing that will not be helping is I've shotblasted with glass bead and then heat treated leaving the surface of the insert smooth.

I have thought about causing the inserts to rust a little to give a better key.


Suggestions please

 

[Keithmac]

What's it for, engine mounts?.

 

[Shox Dr]

What's it for, engine mounts?.

layrub bearings for a Sunbeam

 

[octo0072000]

sickaflex think 221 used to stick roofs on campers will stick steel to steel 24hours to cure fully

 

[Shox Dr]

sickaflex think 221 used to stick roofs on campers will stick steel to steel 24hours to cure fully

It could be a good alternative, however it would need injecting into the mold the prevent voids. The PU is pourable

 

[hermetic]

I bonded some landrover engine mounts, rubber to steel with industrial super glue, permanent fix, doubt the blasting will cause a problem, I would have approached it that way to give a very slightly roughened surface.

 

[frank horton]

I use a polyurethane caulka lot....sticks anything to anything but does need time to cure......
I always use it at the end of the day to cure over night......
bit like no nails but does a better job....waterproof and overpaintable....
loads'a dif colours...

 

[fizzy]

Superglues are the industry go to for bonding rubbers to steel. Abrade both surfaces and sometimes and activator can help. Obviously degrease as well.

 

[Shox Dr]

I did wonder if I coated the

Superglues are the industry go to for bonding rubbers to steel. Abrade both surfaces and sometimes and activator can help. Obviously degrease as well.

I did wonder if SG would work. Do you know if its used wet or let to dry?

 

[fizzy]

I did wonder if I coated the


I did wonder if SG would work. Do you know if its used wet or let to dry?

Do you mean the activator? Usually used wet but there are some you let dry first. Usually used in production to speed up cure so probably not needed in your application. Can help on some tricky surfaces though. Some plastics can be a nightmare to glue. Rough surface is a must.

 

[Keithmac]

Gorilla Superglue Glue Gel is good stuff, thicker than standard superglue, gets into the nooks and crannies.

 

[Dcal]

Shellac is probably the best option, priming with epoxy primer should also work, haven't tried super glue

I would still blast the steel to get a nice rough profile on the steel and also to increase the surface area for the shellac / primer / super glue to grip.

I meant to do a few tests on this very subject but haven't got around to it yet.

PU won't stick to raw, blasted, alloy either.

 

[daedalusminos]

Try Devcon FL-10 metal primer

 

[Shox Dr]

Shellac is probably the best option, priming with epoxy primer should also work, haven't tried super glue

I would still blast the steel to get a nice rough profile on the steel and also to increase the surface area for the shellac / primer / super glue to grip.

I meant to do a few tests on this very subject but haven't got around to it yet.

PU won't stick to raw, blasted, alloy either.

I think the biggest problem is surface finish, I glass bead blasted after heat treatment. This afternoon I left 2 in 50% Sulphuric Acid for 30mins, then coated 1 in Krust. In the mold curing at the mo.

After pouring another it was vacuumed. A lot more trapped air was expelled, far more than prepour degas. Could it be the surfaces of the insert and the mould sides are holding tiny amounts of air?

 

[bricol]

I'm veering off your question (now there's a surprise) I seem to remember you asking about these some time ago, but not much else from then.
Did you contact the current manufacturer of Layrub couplings for possible replacement bushes?

I think a proper vulcanised component will be the only surefire way to go - I have used a few companies around the country that made some rubber coated rollers for me to trial for very reasonable cost. If you've already made the inserts, you're already halfway there.

 

[PhillipM]

I think the biggest problem is surface finish, I glass bead blasted after heat treatment. This afternoon I left 2 in 50% Sulphuric Acid for 30mins, then coated 1 in Krust. In the mold curing at the mo.

After pouring another it was vacuumed. A lot more trapped air was expelled, far more than prepour degas. Could it be the surfaces of the insert and the mould sides are holding tiny amounts of air?

The surfaces are where a lot of the air will form due to nucleation. Smooth on used to do a surface primer for their polyurethane repair compounds, don't know if they still do - IIRC most of them are the same polyofin primer as is used for fitting windshields.

 

[Shox Dr]

I'm veering off your question (now there's a surprise) I seem to remember you asking about these some time ago, but not much else from then.
Did you contact the current manufacturer of Layrub couplings for possible replacement bushes?

I think a proper vulcanised component will be the only surefire way to go - I have used a few companies around the country that made some rubber coated rollers for me to trial for very reasonable cost. If you've already made the inserts, you're already halfway there.

The very same. Too far down the rabbit hole now, and quickly falling down others.

 

[brightspark]

beadblasting peens the surface smooth sand or fine grit blast it

 

[500e]

Zylene is a good bolding agent works at molecular level

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