Pete,
The only serious issue with stainless in salt water is crevis corrosion and
as this is not under water, that problem is not severe. However the big risk
is electrolytic corrosion because of the dissililar metals. The solution is
to prevent moisture from migrating along the thread and becoming an
electrolite. To prevent that and allow easy extraction use an anti-sieze
compond found in auto supply stores. When using stainless wood screws to
fasten the fairleads, use a bedding compound around the screws and under the
base.
Steve

"pete" wrote in message
...
Hi all,
I have bought some aluminium mooring cleats with holes threaded in the
underside to be fixed with bolts from under the deck. I know there are
isues with stainless and aluminium but as there should be no water
ingress to the threads is it ok to use stainless bolts? Or is there
still going to be corrosion.



It's just that I have a load in stock and I'd rather not go and buy a
load more in alloy!

On another issue, I have the fairleads to go with them, but these need
to be screwed with a wood screw from above into the beam shelf. I
don't see anybody selling alloy wood screws so I suppose its stainless
there. So (as salt water is going to be continually sprayed over them)
should there be some sort of protection (paste or plastic) between the
screw and the fitting?

Pete