Patching an Iron keel

[Rhosyn Mor]

I have to patch an iron keel. THere are no large pitted areas, but many small ones. I was going to sandblast, but the yard wont let me. So I have no choice but to patch it. I am planning on wire brusing any rust spots down to bare metal and then patching those spots with Primocon, or rust converter. Obviously will have to feather the paint over some of the paint that is on there now. Are there any issues with this? are some products better at this than others? I cannot change yards so this will have to do until next years haul out. Any other suggestions?
THanks

[Sandero]

The proper way to deal with this is to sand blast and then immediately coat with tar epoxy. Then you can fair with with the usual fairing compounds. This is something I did about 20 years ago and has held up very well, except in a few places where the coating was breached (and requires repair). I was amazed at how many holes in the casting there was. The results are a very fair keel.

[Rhosyn Mor]

DEfjef, thanks, I had not thought of Coal Tar epoxy ( its banned in the UK). I have to patch, not allowed to sand blast, in my research it looks like Coal Tar epoxy will feather into any remaing bottom paint. I presume by standard fairing compounds you mean west system or the like?
Thanks

[David M]

Sand with a 7 inch disk sander where you can down to bright unoxidized steel. Don't torture yourself with a wire brush. Use an epoxy sealer like Interlux 2000 which can be put straight over clean unoxidized bare metal. Don't put any sort of anti-corrosion chemicals over the bare metal that might reduce the epoxies ability to adhere. Put a number of coats over your original coat to build up the thickness, and therefore resistivity to something scratching it down to the bare metal. Interlux 2000 is very tough and its sandable. Use an epoxy filler to do the fairing with another 2 coats of Interlux 2000 over the filler. Antifoulant paint can be rolled right over the 2000.

[cooper]

I agree with above. A good two part epoxy primer after disc sanding (if you cant sand blast). Wire brushing does very little. Ask the question at MetalBoatbuilding.org - Welcome to the Frontpage
A free not for profit group.
cheers

[Blue Stocking]

If you can't sandblast, you might try renting an air powered needle-gun. Have used them a number of times on iron keels.