Best fasteners for aluminium

I need to fasten some aluminium plates to wood dock piers. Under water.
Seems my 2 choises are galvinized or stainless bolts.
This is brackash water, not fresh. There is bound to be a corrosion issue, or electrolois. I'm open to advice.
This is a long term installation
Thanks,

 

Stainless and aluminium will not work if the water conducts electricity.

You can place nylon bushings in the plate so the bolts are insulated. This will prevent electrolysis.

Not sure about the galvanised bolts. The galvanising will sacrifice and then the aluminium hole will erode I think.

If it is not a heavily loaded situation you could use nylon bolts.

You can also get aluminium bolts that might not have any electrolysis issues depending on alloys.

Rick W.

 

How about Wooden pegs?
You'd need Cypress and taper it in a lathe.
For flashing around piers, you have to auger a hole for the Peg, and make the hole in the plate large enough not to interfere with the driving of the peg.
Cypress lasts just about forever uderwater.

 

Assuming a fairly clean, solid surface on the pier, how about a good layer of tar or similar gooey substance from the local hardware shop. It will have the added advantage of not leaving a small gap between the pier, thereby saving the inside face of the plate AND the pier from attack by sea or sea life. Saves drilling and all the associated drama as well, Just a thought

 

Thanks.
There is no electric current involved

 

Use aluminum bolts. Why not??

Dan