Boat ???

SS and aluminum when placed together and wet create a current and do eat the aluminum. In your case, you'll probably be fine for many years. The SS screws on my aluminum canoe have been there for decades now.

But if you were to leave the boat in salt water, and the ss were big pieces, you'd be in trouble quite quickly. Which is why the zinc anode is so important to the aluminum outdrives and lower units on powerboats. Let that anode disapear, and the next thing on the galvanic scale is the aluminum outdrive itself. Which generally is not a good thing to sacrifice.

• Boat metals

I have no idea what kind of dielectric compound you could use in this application. A self-tapping screw is not going to benefit from anti-sieze compound, and anti-sieze is a conductive, not dielectric material.

I buy my stainless fasteners from Jamestown Distributors. Good prices, selection and service. Link below.

• Jamestown Distributors

Stainless and aluminum is the least evil of fasteners you can use.

Regards
Gary

I've redone a couple of those 80's fishing boats, 16' Alcan hulls. I didn't put carpet back in. The first got mahogany plywood with gritty paint for a floor. The more recent I did with fibreglass decks over plywood, the same as on a cabin cruiser. It took about $400. worth of materials and a lot of time, but it did a good job and my boat can sit all summer uncovered in a slip without damage.

You'll likely need to replace a lot of the plywood while you have the carpet out. Something else: a builder taught me to seal the edges of the plywood with epoxy glue and to be sure to fill every void in the end grain. Then the plywood can last.

Good luck with the project.

• Hobby farm