dissimilar metal corrosion

My son was helping me put up the mast last week, when he noticed
the mast base was loose. On inspection we found the base was broken
away from the rivets & was being held on by just silicon. The rivets are stainless steel but the base is aluminum (of course). My questions is/are
would it not make more sense to rivet the new base back on with the same type of metal(aluminum). I know from previous posts that the rivets
of choice are stainless/monel, does this not however mean the base will
again have to be replaced several years down the road due to dissimilar
metal corrosion? This is on a Hobie 16 which is only sailed in salt water.

That is the reason you rinse your boat with fresh water after every time you sail.

It might be better to use larger rivets and drill out to the new size. You will find that with that much corrosion the holes will be too big to put in the original sized rivets.

If that will not work then consider drilling new holes off of where they are presently.

If you use some Lanocote or something similar when you put the new rivets in you will save the aluminum somewhat.

Later,
Dan

The reason to not use Aluminum rivits is they do not have the shear strength required for the laods they will see. Yes, you may have replace the stainless years down the road. But, if it is every decade or so it won't be too bad.

Definitly rinse the boat off with fresh water after each use. I also slather teh rivits in scilicone before I insert them. I don't know if this does anything, but it makes me feel better.

_________________
Nick

Current Boat
In the market
Previous boats owned
'74 Pearson 30
'84 H16
'82 H18 Magnum
St. Louis, MO

Hey Storm

Dans right on with the rinsing, I’ve sailed my boat in salty or brackish water for 21 years now and I almost always have sprayed it off soon after sailing. Twice a year I take it to the car wash and really let err have it. I have very minor corrosion problems.

My boat was two years old when I bought it. About the third time out the mast base let loose while I was stepping it. It’s never a pretty sound! After cleaning the you now what out of my pants, I found that the previous owner had used aluminum rivets in the mast to base connection. I am not sure why a two year old boat had the rivets replaced, but I do know he took it out one time, flipped it in the inner mouth of the jetty, with his wife, and never sailed it again. One guess is that the mast filled and he figured the only way he could get the water out was to remove the mast base.

Mike