I thought metal/rubber/metal bushes were made without actually bonding the rubber, but by a clever technique of forcing an oversize rubber bush between the steel bushes to leave the rubber compressed in a radial direction and held in place by friction. This allows the steel bushes to rotate without actually imposing much shear stress on the rubber.

If you mean engine mounts, these are just steel inserts in a mould.

Jeff

Some bushes are bonded, some aren't. Each has its own advantages, and in our case we almost always use bonded bushes.

I don't know how to get a good bond, I know this can be problematic. I'd guess the surface finish and cleanliness of the metal is paramount, and the correct primer is essential. If the bond fails at the edge of bush that is usually due to poor design - the fillet has to be carefully designed to minise the stresses in the transition.

Cheers

Greg Locock

I read somewhere that one of Michelin's many secrets is the copper plating process used on the steel belt cord that is required for good bonding.  I don't recall having seen a steel mount or bushing that appeared to have been plated.  Maybe the ones that fail aren't plated.

I believe that both Bayer and Akzo Nobel are big on surface preparation, and additives to rubber compounds that assist in the bonding of the rubber to the steel.

This info is based on knowledge from about 5 years ago. With the very dynamic nature of structures within multi national companies, I can't be sure how or by whom these products are now handled.

Regards
pat   pprimmer@acay.com.au
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Lord corporation is big player in rubber-to-metal adhesives. They are marketed under the Chemlock© name.

For additional information, contact Lord Corporation
at: 800-CHEMLOK (800-243-6565), FAX: 814/864-
3452 or write: Lord Corporation, Chemical Products,
2000 West Grandview Blvd., P.O. Box 10038, Erie,
PA 16514-0038.

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