On Sun, 12 Dec 2004 03:54:43 +0000, Jim wrote:

[moved top-post down below OP]

sel1 wrote:
Hi all,

I want to put on backing plates for all the stuff attached to the transom
(exhaust ports, swim platform, steering arms etc). Through continually
snugging them, the previous owner has burried a couple of nuts through the
glass! I am really new to all this but the first thing that comes to mind is
reaction between two metals. If I use stainless bolts, could I use aluminum
for backing plates or maybe I should use something else, or maybe I
shouldn't do this at all?

Still asking and not able to answer much yet.

Thanks, Steve



Steve;
I would look into the reason you have too keep "snugging them", and
there's reason to look at the burried nuts. Sounds like a plywood core
that's rotten.

Backing plates won't help if the center is soft.

Jim


This is good advice. But to answer one of the original questions, I
don't think there is any problem with corrosion between aluminum
backing plates and stainless hardware. For one thing, you will be
putting some kind of sealant in the hole, and this sealant will
probably end up mostly insulating the aluminum from the stainless.
And for another thing, it will take a long time (20 years?) for there to
be enough corrosion on a 0.125" backing plate to worry about.

--Mac