electolasis show through cold tar epoxy

ba_50

Chief Petty Officer
Joined
Apr 4, 2001
Messages
635
I was wondering how effective cold tar epoxy is on aluminum. After applying, a month or so later that white powder look of electolasis starting showing up. Thanks.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: electolasis show through cold tar epoxy

I think we need a little more info.Are you in saltwater?Never heard of cold tar epoxy?
You need anodes and the various components need to be bonded.Electrolosys occurs between 2 dissimilar metals.If they are bonded ,connected together, it minimizes electron flow.If your in a marina wiring faults or a neighboring boat with a problem can agravate corrosive damage.
 

ba_50

Chief Petty Officer
Joined
Apr 4, 2001
Messages
635
Re: electolasis show through cold tar epoxy

I think we need a little more info.Are you in saltwater?Never heard of cold tar epoxy?
You need anodes and the various components need to be bonded.Electrolosys occurs between 2 dissimilar metals.If they are bonded ,connected together, it minimizes electron flow.If your in a marina wiring faults or a neighboring boat with a problem can agravate corrosive damage.

Cold tar epoxy is supposed to make your aluminum like steel. It's been around for awhile.
this boat has been in saltwater and the anodes are gone. I would think this problem would occur in both salt and fresh water.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,065
Re: electolasis show through cold tar epoxy

Coal Tar Epoxy (not Cold ;)) is made for extreme marine environments but it is considered "old school" technology. If the aluminum was not properly prepped then yes..... things could react and start to show through.

If youe anodes are gone....I would replace them.
 

ba_50

Chief Petty Officer
Joined
Apr 4, 2001
Messages
635
Re: electolasis show through cold tar epoxy

How is it prepared? Can the electrolasis be neutralized? Is there something better than cold tar?Thanks.
 
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