Lead keel, non-copper paint

Jun 25, 2004
475
Hunter 306 Pasadena MD
Hi Folks,

Our Hunter 306 has a lead keel which has always been a mess as far as keeping bottom paint on. We epoxy coated it back in 2006 or so, but the paint has always come off in half-dollar sized chunks. I know about the copper/lead electrolysis business, which may have caused some of the problems in past years, but I switched to the non-copper-based Petit Hydrocoat Eco in 2016. Still have problems, but of course, the new paint is going on old, badly adhered stuff.

Anyway, this year, I'm in the middle of taking the keel down to bare metal. My question is: is it worth the extra trouble to coat with epoxy before bottom paint, or can I get away with the non-copper paint directly on the lead. I've read that paint directly on the metal has worked for some. Petit recommends their epoxy as an undercoat, so I'm leaning towards that. What do you say? Anyone have direct personal experience with non-copper paint on lead?

Jay
 
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DArcy

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Feb 11, 2017
1,691
Islander Freeport 36 Ottawa
Lead oxidizes incredibly quickly and the lead oxide layer is a really poor bond. In order to get a good paint bond on lead you will need to clean off the oxide (I used a wire brush wheel) and then quickly coat it with epoxy. On your 30 footer, you will need to do this in a team or in sections because you cannot wire brush and then coat the whole thing yourself quickly enough to keep ahead of the oxide build up. I used West Systems 105, not an epoxy barrier coat.
Of course, wear appropriate PPE. Lead dust is not good for you.
 
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dLj

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Mar 23, 2017
3,373
Belliure 41 Sailing back to the Chesapeake
I would epoxy coat the lead keel. That's what I did on my last lead keel and it worked great.

The manufacturer is saying epoxy coat first, I'd definitely do what they recommend.

dj
 
Jun 25, 2004
475
Hunter 306 Pasadena MD
Thanks, folks. Just got back from finishing the sanding: hands are shaking from strain, not from lead dust. I used the full monti as far as protection (respirator, goggles, tyvek suit), and a shop vac with dust bag and an orbital sander. I think it worked really well for containing dust: also vacuumed the yard ground cover cloth when I was done.

Anyway, yeah: I think this is too much trouble to go the wrong way. I'll use the epoxy that Petit recommends: was leaning that way anyhow.
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
Be sure to hot coat the paint onto the last cost of epoxy. That will help get a good bond for the paint.
 
Jun 25, 2004
475
Hunter 306 Pasadena MD
Be sure to hot coat the paint onto the last cost of epoxy. That will help get a good bond for the paint.
Is that a thing for water-based paint on top of epoxy, or only for the solvent based? I'd sort of think oil and water don't mix...
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
Is that a thing for water-based paint on top of epoxy, or only for the solvent based? I'd sort of think oil and water don't mix...
Interesting question. I use traditional antifouling so I hadn’t looked into that before. It looks like the Interlux Aqua instructions just say to use Interprotect 2000e and follow its directions. The 2000e directions say to hot coat and don’t differentiate between types of antifouling. So yes, I think I’d still hot coat.
 
Jun 8, 2004
10,024
-na -NA Anywhere USA
Not sure if this wold work on lead but Petit Paints has a tie coat process to paint propellers which works. Not sure if that would apply to lead. Suggest calling Mars Metals in Canada and ask them as they produced your lead keel to see what they suggest
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
Just read Trinidad SR is being pulled
That’s what @fstbttms heard anyway -
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
yes, Odessy HD is replacing it.

I did not find that link, but I would suggest calling them for more info, as I did.
Jim...
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
By the way..
It is Cuprous Oxide that is in the paint.
Thus, it is already Oxidized as is the Lead/Antimony keel

Two Oxidized states do not cause Galvanic issues.
Jim...
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
For bonding hardware, Gougeon Bros (WEST System epoxy) recommend wet sanding the bearing surface using epoxy as the "wet". This removes the oxide layer and doesn't allow a new one to form. Perhaps this would work on a keel too? BTW the VC17 or Pettit SR21 (pretty much the same thing) I use on my boat always sticks well to the lead keel. Never flakes off, just wears away as it's supposed to.
 
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