O/T Mating Aluminum Flat Bed to Steel Frame

ChevCase · Sep 19, 2009

Just bought a used aluminum flat bed for my one ton Chev. There were metal brackets bolted to the aluminum flat bed to mount to the other truck. When I took brackets off, the aluminum was badly corroded and pitted underneath. Any ideas on what I can spray, brush on aluminum to stop corrosion before I put metal brackets back on non-corroded areas of aluminum flat bed ? Thanks

D7fever · Sep 19, 2009

Not much you can do to stop the electrolysis of the aluminum once it has started, except cut it out and weld in new. You need to put some kind of "gasket" between ALL aluminum to steel surfaces. the "gasket" can be canvas webbing,rubber, wood, or any other type of similar stuff you can think of.
Someone out there probably knows of some miracle stuff, but I have not heard of anything.
Good luck with the project

John in Nebraska · Sep 19, 2009

Aluminum flatbeds I have worked on usually had a piece of one inch wood between the steel frame and the aluminum rails. Couple of coats of good paint will help, try cutting some insulating washers out of heavy vinyl. Aluminum running boards come with these plastic washers.

Bob Bancroft · Sep 19, 2009

You may want to use something more substantial as advised below, but I have used silicone between steel hinge brkts. and the aluminum frame on a dump box.

Red1 · Sep 19, 2009

Cathotic reaction between dissimiliar materials is a big deal in aircraft mfg....usually a fay surface sealer is used...no I don't know what kind.

BigMarvfromGa · Sep 19, 2009

You need to clean the corrosion either by blending it and applying zinc chromate primer. Then put some type of faying sealer. Silicone will work.

Truckiejas oz · Sep 19, 2009

we use a product here in the marine industry called duralac its a yellow paste that stops the corrosion caused from putting two dissimilar metals together mostly alloy and stainless steel, another is lanolin grease. just give the alloy a good clean with a stainless wire brush apply the paste to the surface's and bolts, bolt it up and clean up the excess and your good to go.
it mainly used in the aviation and marine industrys so check with those guys in your area.
if you use silicone use an non acidic cure one as they tend to get along with alloy better
jason

Billy NY · Sep 20, 2009

Definitely dissimilar materials, the ole galvanic series describes those, just need to provide a good bond breaker like was described to prevent this.

caterpillar guy · Sep 20, 2009

If you put a piece of plastic like a gallon jug, or such between the aluminum and the steel or, the mounting plates it will take care of your problem.

MarkB_MI · Sep 21, 2009

The important thing is to keep water from getting between the two parts. That sets up perfect conditions for electrolysis, particularly if they salt the roads in your state.

I would clean the aluminum as good as you can, and paint it with an appropriate primer. Zinc chromate is commonly used on aircraft, Tempo sells it in rattle cans. Before mating the parts, I would apply a abundant amount of sealant: silicone, polyurethane or polysulfide. I prefer to use polyurethane. That should pretty well stop your problem.

O/T Mating Aluminum Flat Bed to Steel Frame

ChevCase

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D7fever

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Red1

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Truckiejas oz

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Billy NY

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caterpillar guy

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