Body mount bolting suggestions

[goransons]

So I hope to bolt the rear area down this week and had a couple questions.

To increase the surface area I intend to cut a curved piece of aluminum stock, probably 1/4" thick or so and bolt through that down into the rear crossmember and main frame rails.

I want to use aluminum to minimize the dissimiliar metals, however I was wondering if anyone had suggestions for type of bolts to use? Is there a way to somehow isolate the steel from aluminum to avoid issues later? I thought about rubber but in a few years that would break down and the bolts would then not be torqued correctly. I thought about applying a bead of vuelkem between the washer and aluminum surface.

Thanks!

[Aerowood]

A good epoxy primer on all mating surfaces, Plus seal your 1/4" strap into the "C" channel.

[markdoane]

I did the same bolt down using a 2" aluminum channel.

I sprayed the whole thing with a thick coat of zinc.

[goransons]

Ok, thanks! I'll have to check the paint shop and see what they have in the area in small quantities. Are there particular brands of epoxy primer that are better than others you could recommend?

[Kevin245]

Stainless bolts are a suitable option. We use them extensively in our aluminum fabrications. We use nylon, or pvc sheet stock for shims and spacers. I would avoid galvanized bolts.


Good Luck,

[Aerowood]

Originally Posted by goransons

Ok, thanks! I'll have to check the paint shop and see what they have in the area in small quantities. Are there particular brands of epoxy primer that are better than others you could recommend?

I've been using an aviation/marine high solids two part epoxy primer by US Paint but it is real expensive. I've gotten some overspray on some of my exterior skins and two applications of Aircraft Stripper have still not removed it all.
Whatever brand you use is better then a rattle can. And as always, the necessary safety precautions should be observed. So in other words, just use a quality product.

Sealing out moisture from the metals/hardware is the key to preventing corrosion.

Kip

[goransons]

Thanks guys, yes I'm a big fan of stainless hardware, just in general. When I replaced the waste valve on our 69 I wondered why they didn't use stainless screws since it took me 3 or 4 hours to get the rusted ones out in order to remove the valve. Since they are only a few cents more per fastener its definately worth it.

I hadn't thought about a nylon washer added to seperate, surely would last much longer than most other non-metalic options.

Kip I'll check with our paint store that does all the PPG and Zoletone, Por-15 etc and see what they have. I'm sealing the heck out of the back, every precaution I can make, but know that in time water will get in somehow from somewhere and want to do everything I can to minimize damage.