Insulating compound/stainless to alluminium

[jmp]

Buit a boat in 80's and had some paint type of compound for dipping bolts in prior to passing through ally toe rail .Used on assembly to prevent the welding problem when the two metals are in contact .

Can't remember the name or where it came from.

Anybody with info or alternatives please.

<hr width=100% size=1>jmp

 

[tom52]

I asked the same question a few weeks ago.
The answer I got was Duralec, a sticky yellow paste.
I took the advice and got a tube from the chandellers. Cost about a tenner and will last me several lifetimes if it doesn't go off!
The consensus of opinion was you definately needed to use Duralec if you were threading stainless fixings into aluminium but you might get away without it if they were just touching surfaces.

<hr width=100% size=1>

 

[Birdseye]

I have used duralac on the stainless bolts of my aluminium drive leg for 5 years. excellent. no bolt has ever stuck, and the leg is often immersed. and the first and only tube of duralac hasnt gone off

<hr width=100% size=1>

 

[Oldhand]

Duralac is used in the aircraft industry for this purpose, availability in Chandlers for boat use is a recent event. The price you are paying for a tube worries me, I am sure the small paint tins of it used in industry were at least 5 times the volume and probably only a couple of quid each.

<hr width=100% size=1>

 

[Strathglass]

Insulating foam can also be used between stainless fittings and an alloy mast. I will know more about this when I pick up my mast kit later this month. The foam is supplied as part of the kit.
I have had a tube of Duralac for quite a while. It seems to have a long life once it has been opened.

Iain

<hr width=100% size=1>

 

[Chris_Robb]

Duralac is Zinc Chromate Paste. Lasts for ages, But don't get it on anything as it stains permenantly

An alternative solution used on masts is to use insulating tape to form the barrier, and Duralac on the fastenings.

<hr width=100% size=1>

 

[VicS]

Zinc chromate is also carcinogenic, like many other chromates. So keep it off youself as well.

<hr width=100% size=1>