Ospho and treatment for flaking keel

[Bob Pullen HC-33 1981]

Found a bunch of flaking growing steadily on the keel.
I can see gray shiny good "metallic" surface when the flaking occurs.
Posted about this in Dec.'12 (http://forums.sbo.sailboatowners.com/showthread.php?p=984802) and got great advice.
However, still unsure about the makeup of the keel, iron, lead, steel, ??
I'm also hearing about how I should "Ospho" the keel right after it is bare, then west epoxy w/ barrier coat, then paint?
Has anyone used this approach?
Many thanks,
Bob
S/V Seanorita
Puerto Morelos, Mexico

 

[wetass]

Ospho is only going to work if you have a light coating of surface rust. It converts the rust to make kind of a bonded primer. If its clean metal, it won't really do anything. I suppose if your just using it to convert any remaining light rust after aggressively removing any scale, etc, that might be useful. But, it would be a waste if you ground everything down to clean metal.

 

[Cool Beans]

Flaking iron doesn't reveal a "shiny metallic surface" when peeled away. . .it reveals typically "black rust" which has it's own name which escapes me

I've got about $3.50 on it being lead.

If it is lead, do you need to do anything but paint over it?

 

[kloudie1]

I am with you Beans.. Those boats were supplied with a lead keel.. Take off the flaky stuff and fair what is left and paint with a primer that is suitable for lead. A self etching primer like this :
http://www.pettitpaint.com/product.asp?id=86
or similar.. Osphos is for iron, steel or aluminum but not so good on lead.

 

[Ross]

Thumping with a small ballpeen hammer with quickly tell if it is iron or lead.

 

[Bill1565]

Found a bunch of flaking growing steadily on the keel.
I can see gray shiny good "metallic" surface when the flaking occurs.

LEAD. No Ospho.

 

[Bob Pullen HC-33 1981]

Many, many thanks
Supposing it is lead, would there be any advantage to coating it in west epoxy w/ barrier coat additive, once grinded clean? Does lead look lightly gray metallic when freshly flaked-off top layer comes off? What am I looking for when thumping
Thanks
Bob

 

[Ross]

dents.

 

[Cool Beans]

fresh lead has a shiny grey color to it. . .go to your local tackle shop and look at their big sinkers, that will give you an idea.

Lead is pretty soft, if the hammer test fails to work for you. . .you should be able to take a sharp pen knife and cut a chunk out.

Any sanding / grinding you do on a lead keel. . .please wear proper protective gear and something to contain the dust. Lead dust is toxic, and could leave you sterile or dead :naughty:

Coating it in epoxy resin I think does more to allow for easier paint application vs protecting the lead. Oxidized lead doesn't hold paint or anything really well

 

[Bob Pullen HC-33 1981]

Yes, lead it is! The analogy to the shiny sinkers did it...exactly what I saw when I peeled away the flaking stuff, while diving/scrubbing recently.
Once it's ground clean throughout, still not sure about preferable sequence: primer, paint or epoxy, sand, paint, or primer, epoxy, sand, paint? Any suggestions?
How about the seam where the keel meets the hull? Any special treatment, taping, paint sequence, etc, there?
Thanks for all the great input!