S/s bolt into cast aluminium body.

[Mudisox]

I have duralac, and realise the problem of dissimilar metal corrosion. Can I just dip the end of the bolt in duralac before threading and tightening the bolt?
It then passes through a rubber mat and grp deck to a large s/s washer and two nuts to affix.

 

[AngusMcDoon]

Yes. It's sticky stuff and gets everywhere. White spirit cleans it up. It tends to separate in the tube and you just get brown liquid comes out after it's been sitting a while. Poke a thin screwdriver in the end and stir it around while massaging the tube. The yellow stuff is not good for your health so wear disposable gloves.

 

[ean_p]

So its not into a casting but through a casting? Is the hole in the casting threaded or plain. If plain is it wide enough to 'sleeve' the bolt? Can it be made wide enough?

 

[NPMR]

The cast aluminium casing holding the morse throttle lever on our then fairly new Jeanneau had stainless bolts holding it together. The Powder coating flaked off wherever a stainless bolt had come into contact with the aluminium.

It took me three days to get the thing apart as a result of the corrosion.

When I put the recoated unit back together again, I used Duralac everywhere. I also put plastic washers everywhere I could so the new stainless nuts and bolts did not actually touch the aluminium anywhere and drilled the holes out as well, to give space.

Now, a good few years later there is no hint of a return of the problem.

Stainless and aluminium together seems to be a bad idea on a saltwater boat.

 

[dankilb]

I think you are technically supposed to let it dry - no? (Takes minutes not hours)

Or at least I assumed so because of the mess involved!

Now I use Tef Gel for routine threaded fastener use. Would save the Duralac for something like a SS backing plate, washers, brackets, etc.