aluminum and stainless steel together in sea.

[damkitu]

Hi all,

I'm building a piece that will stay in sea water and I need to have a piece of stainless stell 316 and a piece of anodized aluminum piece in contact.
Is that possible or will have for sure some electrolysis that will corrode the aluminum?
so far I have done samples using some 100% aluminum and it does corrode very quick..

I was thinking about using some Aluminum A-G10SBe (i.e. with about 10% magnesium, some Silicium and Beryllium) with some Cadmiun anodization does anyone have had experience with this before? does it work? and if not, what type of aluminum would you recommand instead of the one I picked?
note that the aluminum piece is a casted piece so I must use a "casting friendly" aluminum.

thanks a lot in advance for any help,

Damien.

can you isolate them, like with a gasket of engineering plastic, or sleeved screws. or how zakkly are they attached?

[damkitu]

Hi,
thanks a lot for your reply,
well no I can not really, the aluminum piece has two holes in it where a stainless steel rod is jammed in and then a piece of stainless steel is rotating around that rod.
do you think there is no way it is going to not electrolyse and corrode?

[charmc]

Originally Posted by damkitu

Hi,
thanks a lot for your reply,
well no I can not really, the aluminum piece has two holes in it where a stainless steel rod is jammed in and then a piece of stainless steel is rotating around that rod.
do you think there is no way it is going to not electrolyse and corrode?

If you think about it for a while and do some research, you should find ways to isolate the metal surfaces. Lazeyjack's steering you right, focus on that principle and you should be able to think of ways. Any plastic or elastomeric coating, gasket, sleeve, etc. will do, so long as it prevents the dissimilar metals from touching. Might actually help in reducing friction on the piece that rotates. If this is new construction or modification, think of overboring the holes enough to insert a plastic sleeve.