Galvanic corrosion

[smashweld]

What would be the better scenario here....it's to join 3mm steel channel to 3mm alu channel @ 90 deg so same surface area

6mm thick alu angle touching 3mm mild steel
or 3mm thick steel angle touching 3mm alu

Also when putting steel rivets in alu what to use as a barrier?

Cheers

 

[MoreWellie]

I am sure there will be aircraft engineers on here who know chapter and verse but I would suggest a layer of plastic between the two will help

I have also read that galvanising the steel reduces the rate of corrosion

 

[Paul Irvine]

I'll chip in with my view, we do a lot of stainless and ally on these.

You need to separate the two materials to prevent the galvanic action.
You can use a mechanicall barrier like an isolation material such as mylar sheet or tufnol
Rivets are a whole separate problem, ally rivets through steel will have the rivets rot, stainless through ally will cause corrosion in the ally.
When we need to join two together like steel and ally I advise using "monel" rivets a barrier between the matting faces and the rivets would be dipped in a chromate paste such as Duralac or JC35
Paul

 

[Shox Dr]

ships chandlers, will have anti galvanic paste

 

[colnerov]

Hi, Anything that insulates, a coat of paint would be enough.

Colin