I have just double check with my friend who worked as a welder for 35 years
in a shipyard that build commercial, coast guard vessels, battleships and
drilling platforms.
If you have an aluminums structure welding steel plates on or doing the
reverse was not in practice. Aluminums and mild steel or cold rolled steel
are not compatible. The same thing applies to welding stainless steel.
What takes place is a white inter granular corrosion that is hardly visible
to the naked eyes. Given time the white corrosion will cause a structural
failure. Not to mention the saline atmosphere at sea that will accelerate
the process.

"André Langevin" wrote in message
...
Hi to all,

I am a newcomer on this newsgroup and you'll see me around as i'm starting
the construction of a new boat. I currently have a 34 feet powerboat in
aluminum and my nest boat will be a 44 or 45 steel sailboat. I'm looking
at building a Bruce Roberts design and i would like the deck
superstructure to be in aluminum. I've seen many commercial boat done
this way and even old Coast Guard patrol boat of 30+ years old without any
corrosion problem so it is something i'd like to do. But i can't find any
industry that carries the special strip that isolate both metals but still
permit to weld them both.

Does someone ever see this ?

André