Iron keel refurbish.....

Brian S · Oct 8, 2016

Strip it to bare metal as best you can (industrial sand blasting, needle gun for any rust scale.) 2 coats Ospho phosphoric acid to create a non-reactive iron phospate coating. Then 2 or 3 coats of marine grade Coal Tar Epoxy (it's what they use on buoys,) fill/fair/sand, then 2 more coats of Ospho and CTE to take care of any burn through from sanding. Then your favorite bottom paint.

weinie · Oct 8, 2016

Grind down. Immediately coat with Interlux 2000e before rust sets in. Follow directions for repainting bottom.

Ken Cross · Oct 9, 2016

Brian S said:
Strip it to bare metal as best you can (industrial sand blasting, needle gun for any rust scale.) 2 coats Ospho phosphoric acid to create a non-reactive iron phospate coating. Then 2 or 3 coats of marine grade Coal Tar Epoxy (it's what they use on buoys,) fill/fair/sand, then 2 more coats of Ospho and CTE to take care of any burn through from sanding. Then your favorite bottom paint.

That's what I did in the spring of 2015 only instead of Coal Tar Epoxy I used Interlux 200E (2 coats I think but not sure if I did a 3rd) and repainted with bottom paint. It was pretty rusty and ugly. I pulled it out of the water 3 weeks ago and it had no rust showing through. I had used copper free bottom paint and it had failed miserably, but no rust. Now it's back in the water with new bottom paint (Micron CSC) and a dripless shaft seal. We'll see how it goes.

Ken

DougM · Oct 9, 2016

weinie said:
Grind down. Immediately coat with Interlux 2000e before rust sets in. Follow directions for repainting bottom.

I had some rust under coating blisters on the iron keel of my 323. Evidently this was a common problem due to improper original surface preparation by the manufacturer of the keel. Rumor had it that the keel manufacturer was no longer in business, therefore no recourse.
I ended up completely grinding off the original coating which was not adhering to the iron. As soon as I was down to bare metal, I began to recoat with Interlux 2000e. Ultimately, I put on 3 coats of 2000e within several hours of one another so that there would be good adhesion between coats. I followed that with 2 coats of VC17 ( fresh water boat) which bonded to the 2000e.
It has been four seasons, and there are still no signs of deterioration in the coating.
The boat is on the hard all winter, and even severe weather hasn't caused a problem.
Unlike those who can leave their boats in the water for more than one season, I routinely repaint the bottom every spring, even though the bottom paint might last more than one year.

Jim 5757 · Oct 9, 2016

Similar procedure with our old Hunter 23. Sandblasted to bare metal, sanded with 60-grit until shiny, then immediately coarted with Interlux 2000E per mfr instruction. That was 15 years ago, and as of last winter, it's still good!

Jim 5757 · Oct 10, 2016

Boat was on the trailer. Had to lift up to gain access to the bottom.

Crazy Dave Condon · Oct 10, 2016

When prepping the metal, all rust/corrosion has to be stripped down whatever method you use. Sand blasting should be done by someone who is experienced and of course outside with the hull masked off to prevent damage. I would suggest then applying a metal primer that does include what I call zinc chromate to prevent further rusting in the future. Fill in the voids with a two part epoxy which I found that Water Tite worked well for this application but more expensive and slower to cure which in a way is good. Many yards will tell you then apply epoxy barrier coats minimum of three but the more the better as I always said. On all boats painted at my yard, a minimum of four coats of barrier coats. As for bottom paint, that will depend what is used for the purpose of application and of course what works well for that area. I always suggested you ask the local yards what works best and go with that which is why I would call if the boat was going out of area and ask what worked for that area.

DougM · Oct 10, 2016

NYSail said:
doesnt seem so bad.... bottom was done while hanging?

I would not, under any circumstances, work under any hanging load!!!It is just not safe. Boat should be supported with stands, or on its cradle.

Steve Dion · Oct 10, 2016

Check out POR-15. There have been several posts on the site in previous years.

Gunni · Oct 10, 2016

POR-15 is not recommended or spec'd for marine use. The coal tar epoxies don't have the hard-coat shell you want on your keel. Currently Pettit Interprotect HS Epoxy primer is the toughest, stuff you can put on your iron keel, and it goes on thick. Peel off loose rust and scrub the first coat of epoxy primer into the bare metal with a wire brush.

Charlie Jones s/v Tehani · Oct 10, 2016

Gunni said:
POR-15 is not recommended or spec'd for marine use. The coal tar epoxies don't have the hard-coat shell you want on your keel. Currently Pettit Interprotect HS Epoxy primer is the toughest, stuff you can put on your iron keel, and it goes on thick. Peel off loose rust and scrub the first coat of epoxy primer into the bare metal with a wire brush.

I've had Coal Tar epoxy on my iron keel now since 2006. Has held up extremely well. MUST remove all rust, etc first, then 2 coats Coal tar, then Interprotect, then bottom paint . No signs of ANY trouble.

Ken Cross · Oct 11, 2016

NYSail said:
Ken how did you strip it? Sand blast?

I used a cheap Harbor Freight 4.5 inch angle grinder with an abrasive 36 grit flap disc attached. I had to build a tent around the keel to keep the dust under control. It was messy.
Ken

Steve Dion · Oct 11, 2016

According to the mfg of POR15 it can be submerged in water after it is cured. The yard used this stuff on our H'31 keel many years ago and it did fine.

Gunni · Oct 11, 2016

Steve Dion said:
According to the mfg of POR15 it can be submerged in water after it is cured. The yard used this stuff on our H'31 keel many years ago and it did fine.

The manufacturer of POR-15 does not endorse use on iron boat keels.