Steel on Aluminum?

I am building a transom trolling motor bracket out of a piece of steel angle. Want to make sure the two metals don't get into a "fight". Can anyone suggest a paint for the steel or related process to make sure the two metals won't corrode?

Use a piece of plastic (vinyl rain gutter) to separate the two or just get an aluminum angle which is what I would do.

Any time two dissimilar metal touch electrolysis can occur. As a result, it's best to use like metals whenever possible (e.g. aluminum on aluminum). However, stainless steel will not react in the same way as most other metals under marine conditions, which is why it is the industry standard for all saltwater boats. Unfortunately, most "freshwater" boats (bass boats, etc...) are built to a much lower standard using cheap galvanized steel hardware which inevitably rusts. Save yourself the hassle and upgrade everything to stainless, marine grade if possible. Buying in bulk will help save you a few $ too. Be sure to use some 3M 5200 marine caulk on any through-hull hardware as well. Using a paint, or washer will only delay the inevitable corrosion.

Do not do it - you will end up with a mess of rust and galvanic reaction - just the rust flowing from the steel will react with your alum. boat


Use Alum as was said above

What if I get my local LineX truck bed liner dealer to spray it first. Do you think it will penetrate through that? Does anyone have any opinions on that?

The cost of linex will probably be higher than the cost of aluminum. Also, it will add a lot of thickness to the part.

Do a little leg work and call some metal fab places and ask them if they have any scrap AL angle they will sell you. You should be able to find some without having to buy a 10’ piece. If this boat is going anywhere near salt water, you will be sorry.

I have redesigned with aluminum. Thanks for the advise

Whew, good. Ye had me worried there a minute! Don't mix them rascals...