Pontoon Boat & Deck Boat Forum

Hi Guys:

I'm getting ready to bolt a U-shaped center log to my cross members. It is a simple flange design.

Are there any specifications for the stainless steel bolts I'm going to be using - and should I put some sort of inert spacer (hard plastic?) between the flange and cross members to discourage galvanic corrosion?

The best stainless to use is type 316. It has very high corrosion resistance.

I would recommend it especially in salt water conditions. A great product is tef-gel. Not only does it stop galvanic reaction but it also works like a never seize. The military uses it all the time for any bolts that are subjected to corrosive conditions, e.g. anything bolted on a deck of a ship etc. Also used in the hurricane industry for stainless nuts and bolts in aluminum shutters.

Great product to have for any dissimilar metals and/or nut bolt applications in any marine corrosive conditions. And a little tube goes a long way.

BTW I do not sell or rep it but many moons ago I did work at a company (ERO Inc) that use to use it in there product assemblies. Since then I always use it on nuts and bolts, or with dissimilar metals.

Type 316 is the way to go. I have them all over my 1993 Playcraft after the first 15 years in salt and brackish water with no visible crevice corrosion or wastage in the aluminum. As long as air can get to the fasteners and no stray current, you will be good to go