Stainless Fittings on Painted Mast

[CarlF]

I need to install some new stainless fittings on an awlgrip painted mast. I know to use TefGel on the stainless screws but what should I put between the back of the fitting and the mast to stop galvanic corrosion and avoid bubbling paint? I've also been told that some solutions will provide electrical insulation but still trap water that causes corrosion. I've had suggestions for:

Silicone caulk

4200

Pieces of cut up Clorox bottles

Electrical tape

Cover the whole back of the fitting with TefGel

Nothing - the paint is an insulator

Thanks

Carl

[quartersplash]

Hi,
I am in the process of redoing the mast off the boat and am interested in the same question. I have tefgel also for the screws and a durable rubber, very thin with a fabric inside to keep it from squeezing out from under the fitting.

[FloridaWriter]

I use thin Teflon sheeting between the hardware and the mast; and caulking of some kind in the tapped screw holes. I have not had a bit of corrosion with this method over the past 20 years.

Current modifications to mast of my Bristol 29

[David M]

I use nylon washers quite frequently. If it is something that is going to be heavily loaded and might compress the nylon washers then I would use a thin Delrin spacer.

Whatever sort of spacer you use, take into consideration the loading so that you use a material that will not distort under the compression. Teflon is pretty soft but under light loading works great. Nylon is a little harder and Delrin is very hard and very resistant to distortion. Definitely use the Tef-Gel for the stainless steel fasteners into the aluminum.

I find that with caulk for this kind of application it almost always fails because it eventually delaminates from whatever it was applied to, allowing water in.

I have successfully stopped Awlgrip from bubbling up from aluminum corrosion where I have threaded stainless into aluminum by bedding the heck out if it with Tef-Gel. You may not need any plastic spacer at all depending on the application. Tef-Gel will remain a soft sticky gel that displaces water for many many years without changing its physical properties or washing away...that's the beauty of it.

[s/v Jedi]

Tef Gel for the fasteners and either thin Teflon sheet or thin (hard) neoprene rubber sheet between paint and hardware.

Our mast is 15 years old and has some paint off. For testing I cleaned some of these spots to the bare aluminium and just rubbed some tef gel on. It's still exactly like that after 4 years; I can still feel the tef gel is there. Amazing stuff.

cheers,
Nick.