Sunday, September 11, 2011

Keel, Rudder and Bottom Work

Before any work
The culprrt: poor maintenance of the forward
part of the joint allowed water to penetrate along the length of the joint.





(All images @ https://picasaweb.google.com/113905172205315068165/ElizabethKeelAndBottomWork)

The big job at hand is to strip the keel back to bare metal, apply an epoxy barrier coat, reseal the keel/hull joint and fair and paint the whole mess (including the entire bottom). The rust visible on photos above is nothing to worry about, just surface rust. It does, however, indicate that the old barrier coat has failed. I received a quote from Oak Harbor Marina to strip, barrier coat and paint the keel --  a mere $2400. So I will, obviously do the work myself. Alas.

Armed with hammer, chisel, scraper, random orbital sander, angle grinder, shop vac, dremel, safety glasses, hearing protection, and respirator I set to the job of stripping the keel of all the old material. This is a seriously SLOW and laborious task. It would go a lot faster with a sandblaster, but the yard won't allow it.

The First Weekend
After most of a day's work I managed to expose the keel/hull joint and chip away at some of the old barrier coat. The joint was faired with a material that looked a lot like Bondo. It adhered tenaciously to both sides of the joint, but not over the area of the joint itself. Ranging from 1/4 to 3/8 of an inch thick it took  a couple of hours of careful chiseling to expose the joint.

The surveyor was right, the polyurethane sealant in the joint remained intact, except at the forward end. My worries about moisture getting to the keel bolts was unfounded. I used the hook scraper to dig out as much of the old sealant as I could reach, leaving just some detail sanding necessary before applying a new bead of 3M 5200. I will prep the joint on both sides of the keel before sealing the joint.

After a couple of days of VERY slow going with lousy sandpaper and  lots of hammering and scraping, I decided to purchase a dust hood for my angle grinder. With the grinder I can use a wire brush. I am hoping this will go faster.

The Rudder: Day 1





I also began the repairs on the rudder. The starboard side of the rudder had a couple of wet spots with one serious area of delamination. I did a quick sand job just to expose the high points, then drilled a bunch of holes in the bottom of the rudder and a couple on the top to allow the water to drain. Water flowed as if the faucet was left on! I let it run for a day and on day 2 started to cut out the areas of delamination. I was surprised to find no fiberglass cloth or matting -- just thickened epoxy. Below the skin is a very dense foam material. I hope when I relaminate the cut out areas the epoxy will adhere to this stuff!






After 4 days ... damn this is slow going. Found the fastest method was to remove as much as possible with a hammer, chisel and stiff scraper. This will get off most of the old barrier coat without creating too much dust. Then the angle grinder with a sander attachment will do the most of the rest. Finally finish off with a wire brush. The orbital sander is worthless.

September 17 2011
After a week finally a coat of epoxy is on the port side of the keel and progress is being made on the starboard side.






September 24 2011
Two weeks later and both sides have at least one coat of epoxy and the keel/hull joint is sealed with 3M 5200.

Before any work on the starboard side

Starboard side -- joint sealed and fairing begun

Taped the joint for a neat joint line
October 5 2011

Almost a month later and the keel, hull and rudder are as done as they are going to get. At some point you have to give up on perfection and recognize you are out of time. And boy did I give up on perfection! The keel has been stripped, the joint refreshed and the area has been (somewhat) faired. More time and I would have made a perfect fairing job of it. Alas.





After one coat of bottom paint ...






















And The final product ... after two coats of bottom paint.



2 comments:

james Watson said...

Hi Kurt, Nice job on that keel--it's a bear of a job! I'm in the midst of the process and also foudn that a hammer and chisel worked the best for demo-go figure?!

Couple questions on the longevity of your repair:
1) Using plain epoxy as the barrier coat, how did that hold up over the last couple years? I am trying to decide between epoxy and POR-15 (epoxy is cheap/free in my circumstance)
2) Did you wire brush the epoxy on when you applied it?

Thanks!
Fraser Watson

Kurt Reitz said...

James,

After two years the repair held up flawlessly. I have not hauled the boat this year and really have no idea how long the work will last. I have no experience with POR-15 so I have idea how well that will work. Sigh. Yes, before applying the first coat of epoxy I sanded, cleaned with a tack cloth, then with acetone, then applied the epoxy with a foam brush, then brushed it with a wire brush and tipped it off with vertical, diagonal and horizontal brush strokes with the foam brush.. I applied six coats. There is a post where I outlined the procedure as best I could.