Keel Restoration

And now, the story we've all been waiting for: The Infamous Keel! This is definitely one of the problem areas for the Tanzer and it is well known There have been more postings about the keel on the Tanzer Yahoo group than for any other subject. I read every single post concerning keel work. The general concensus was to use a product called POR15. There was also a lot of talk about how to prepare the keel. Some dealt with sandblasting equipment which was beyond the scope of what I was willing to try. Besides, there was no place local that I could find to rent the equipment. Other suggestions included grinding, sanding and scraping. Before starting this project in ernest, I tried a small section with these special stripping attachments for a drill. They didn't even make a dent. Then I tried grinding. The wheel got clogged very quickly with some kind of soft fairing compound that had been used on the keel.

Below is my pictorial keel story. Click on the thumbnails for a larger picture.

Keel Preparation

After trying several methods to remove the old stuff on the keel I was almost ready to give up. Then I remembered one post on the Yahoo group about pounding it with a hammer to break off the old stuff. It worked pretty good. The hammer cracks the stuff into chunks that either fall off or come off easy with a carbide scraper. That is how I did the whole keel. The tarp catches the stuff that falls off so I don't mess up my yard with who knows what.

The fun begins! There has got to be a better way then grinding!

I counted 15 layers of various paint, epoxy, fairing compount. I am guessing that since the boat is 25 years old that the keel has never been completely stripped. If that is the case, it is about time to do it right.

I think we're down to the Cretaceous Period

The carbide scraper is a great tool. It got pretty much down to bare metal except for the small pitted areas.

Great tool, carbide scraper (invented by the cave people, hey, they had sailboats too)

Some areas went pretty fast, especially the rusty spots. Other areas were slow going, especially up by the keel/hull joint. It took about 1 day per side then a day to clean out the joint.

About 1 hour of work!

I always look at the job as being half done, not half left to do. Sort of like the beer half full.

Half done (sort of)

A quick run over with 80 grit paper got the keel about as close to bare metal as possible.

Sanding with 80 grit to get rid of as much of the residue as possible.

I kind of like the bunny suit. I think I'm going to start wearing it everywhere. It was great to be able to work on the keel for a few hours, then just zip the suit and gloves off and not be a real mess. I highly recommend the respirator for any kind of sanding job. Much more effective than the silly filter masks.

Who is that masked man? Why it's Keel Man!

The hard part is done! It really wasn't as bad as I thought it would be once I figured out the hammer bit.

Done sanding!

I expect this is a casting defect and not an artifact of a grounding.

Casting imperfections?

Old caulk is really nasty stuff to remove, especially on the bottom of the boat in a narrow crack. Nothing really seemed to make this task easier. I just kept picking at it.

Oh, that nasty hull keel joint!

I tried everything. Carbide scraper worked OK on most of it. I ground a old screwdriver to make something with a hook to dig the caulk out. I also used a saw blade and thick gloves to pull the caulk out. The wire wheel worked well on stuff near the surface. I even tried to make a little blade out of a washer. That didn't work too well.

WCD, Weapons of Caulk Destruction

After a while I decided that all the old caulk didn't have to come out, just enough to ensure a good seal when the new caulk is put in.

Joint scraped out as much as can be done (about 1.5 cm)
Refinishing the Keel

I followed the instructions for the POR and washed first with Marine Clean, a strong degreaser and cleaner. I think this is more for engines but I did it anyway. Next is the metal prep which did a great job of getting rid of the rust. Not sure exactly why that is necessary because they say that a layer of rust is actually good for better adhesion of the POR.. Anyway, I didn't have a choice because after washing the metal prep off you will have rust almost immediately.

Starboard side after metal prep

There were a couple of spots where it looked like a repair had been done. There was no rust! Maybe it was a zinc based filler or paint. Wish I knew what it was.

Some kind of filler or patch with no rust

Finally got a day without rain. Here you can see the first coat of POR going on. It is very easy to paint and it flows easy. Better to have two thin coats than one thick as this stuff will run.

I love you POR!

Done the first coat. Let dry for about 6 hours till it is dry to the touch. This stuff is pretty bullet proof.

Starboard side, first coat POR

The second coat is a little tougher to put on only because it is hard to see where you have painted. After this day of good weather we had 21 days of consecutive rain!!! That's a good thing and a bad thing. Because of the rain I delayed my launch by three weeks. We had a wicked nor'easter that wrecked many boats and docks, even closing one for the season. The dock where my slip is was heavily damaged and they had to pull it out to rebuild. The boat next to where I was supposed to go was demasted! So in a way I'm lucky I didn't put on my first launch date.

Two coats of POR done!

Once the weather cleared and I was no longer under pressure to finish I continued by caulking the hull-keel joint with 4200. Apart from the angle of the caulk gun this went pretty well. I let it cure for about two weeks..

Hull-keel joint filled with 3M 4200

I sanded the POR with #350 sandpaper to provide the epoxy with a little grip.

Two coats of POR, sanded with #350, ready for epoxy fairing

This was my first attempt with using filler with the epoxy. I used 410 Microlight from West System. The first coat was a little too thin and it sagged a little in a few spots. I sanded those down but went through the POR which I then touched up.I mixed the epoxy a little thicker next time and had no sagging. The other thing I did wrong was I assumed this stuff would cure in about 5 minutes based on my experience with Bondo. This stuff has a much longer working life, maybe 20 minutes, which means you can take your time.

First coat of epoxy. Some slight sagging

This was the tricky bit. I used a piece of paper board as a straight edge bent to the shape of the keel's leading edge. I then plopped a big bunch of epoxy on it and dragged it up the keel. I only had to make a few touchups with the spreader to get everything smooth. Better to put it on as close to what you want as possible to reduce the amount of sanding.

Fairing before sanding

I really didn't spend a lot of time fairing. I just wanted a smooth surface and not necessarily the perfect foil shape. Besides, from what I understand about the class rules that is all you are allowed to do.

All done fairing and sanding

It came out pretty good with very little sanding. Of course, what do I know what is good, being the first keel I ever worked on.

Used #80 for rough sanding

I did the same thing on the trailing edge as I did on the leading edge. For the sides of the keel it was just filling in any voids made by rust or any casting imperfections.

Trailing edge after sanding

I put the first coat of bottom paint on right over the epoxy. It went on pretty thick and dried fast. I will put the second coat on at the marina once I can get under the pads and the bottom of the keel. I did have to thin the bottom paint a little to keep it from clumping when I painted.

Done first coat of bottom paint (Pettit Horizons)

It looks much better with the first coat of bottom paint. The time spent with the epoxy was worth it now that the paint shows how smooth the keel was.

Look Ma, no rust!

I decided to pay the marina to put the boat on stands rather than come up with a system to raise the boat on the trailer to get under the pads and keel. This decision was based on comments from the Yahoo group. I did notice a little crack in the paint where the hull/keel joint was due to lifting the boat. I guess this is normal as long as the caulk in the joint is flexible.

At the boatyard on stand to get the bottom of the keel

I sanded down the bottom of the keel as best I could, put two coats of POR on, then faired with epoxy, then two coats of bottom paint. I was able to do this all in one day. I also did the final coat of bottom paint that day too not to mention stepping the mast and other launch preparations. It's amazing how much work you can get done the day before launch!

I think it has been a long time since this part of the keel has been done.

The final product!! Hopefully it will be rust free when I haul out this fall. It's funny to spend so much time on something not normally seen.

Wow, that was fast! Bottom of the keel done same as the rest.

Just a final note about the keel. I think of working on it as a rite of passage for a new Tanzer owner. I tend to think a little bit of my soul (and blood and skin and sweat) is now part of this boat. I can almost sense that the boat is happier now (OK, maybe it was the celebratory beer I had).