Hull/Keel Maintenance Advice for Newbie

[ryan865]

I just bought my first boat, a Catalina 25, and had it hauled out yesterday. I plan on sanding and painting this weekend. But, before I dive in head first, I would like some advice from those with more experience. I am brand new to this.

I didn't see any blisters or cracks on the hull. However, it looks like the keel has corroded where the paint has come off.
Should I just scrape this away or try to sand it?
Does the hull even need sanding? or just clean and paint over?
Any recommendations for ablative?
Where do people buy the protective coveralls?
Should I buy 3 quarts or a gallon of paint?

Attached are some pics of the hull and swing keel.

Any advice, comments, recommendations appreciated.
Thanks,
Ryan

[rw58ph]

I sand the bottom each time we pull, before applying the new bottom pain. The reason is not to built up to thick of bottom paint, and make sure the hull is clean so the bottom paint sticks. As for blisters if they are smaller than a dime, I just break them, sand and paint. Be careful as blisters are very toxic. If the blisters a bigger and deeper then sand, epoxy before bottom paint.

I use my oldest cloths, and buy cheap throw away roller/pans. I would apply two coats so gallon first and then quarts to finish if needed. In my younger days I did the whole hull in three days, but now I have it done.

[ryan865]

Things went from bad to worse today while sanding my poor swing keel.

As I was sanding all of the crud off, some of the paint starts flaking off in large chunks and then I realize that the keel is flaking off as well! It is corroded so badly that it just crumbles away.

The pics show palm-sized areas where bare, corroded keel is completely exposed to the elements. Also, all of the white areas appeared once I began sanding.

What should I do?! The only thing I can think of is to keep sanding, patch the bad spots with filler, and paint over. But I don't think this fixes the problem.

Please help, your advice is needed.

Ryan

[gabilo]

Get an angle grinder and clean it all down to bare metal, prime and re paint

[Lojanica]

grind to good material. Coat with thin neat epoxy. Fair with filler as needed then prime with high build then paint

[bornyesterday]

Swing keel is, I believe, solid cast iron? If that's so (and after dealing with any pivot/cable issues) I'd use my air chisel and its needle scaler attachment to remove all the thick, loose stuff and then review the situation.

Either convert remaining rust chemically or remove the keel & blast it depending whether you can reach everywhere you need. Cast iron can lose a lot of surface metal to corrosion without it affecting its utility.

I wouldn't use filler on it at all except in the case of serious holes. Those I'd grit blast before epoxy filling.

A chipping hammer (used in welding) takes longer than a needle scaler but does the job eventually. Got to be careful not to hit the grp with tools or grit

[ryan865]

Thanks for all the tips! It looks like I have two options.

1) Grind to the metal and redo epoxy, primer, paint.

2) Patch with rust converter, and paint over.

Seeing as how I am still very new to this and the boat has to be back in the water in less than two weeks, I don't have the time or know-how to do a proper grinding job. I don't even know how to take the keel off and I just used an orbital sander for the first time today!

I will sand off as much corrosion as I can, use rust converter, paint, and hope I still have a keel when I pull her out next winter.

[ryan865]

Do I need to use primer over the areas that have the white patches?
I am not sure what it is, but it doesn't look like it will hold the paint very well.

[bornyesterday]

Orbital sander is no use on flaky or thick rust - would take forever on thick paint/antifouling too. Waste of time and abrasives.

Thick coatings and thick rust are much easier to chip off than to sand or grind off. Even a 9" angle grinder isn't as effective on thick, flaky rust or on thick paint as chipping is. Think of a hammer and chisel - a chipping hammer has one chisel end and one point end. Hammer and chisel in one.

Air chisel & needle scaler are just much faster and easier than using a chipping hammer. An SDS+ hammer drill can substitute if you fit a chisel in it. Doesn't matter if you can't stop the chisel rotating.

If you're still not convinced try looking online to get an idea of how things like steel bridges are done. Descaled (chipped) first, then grit blasted is most effective and usual.

[CarlF]

Here's a contrary opinion. Don't worry about it. Don't even paint it with antifouling. If it makes you feel better, paint some rust reformer on the worst rust.

Paint the rest of the bottom with anti-fouling and go sailing for the summer. This rust didn't start last fall. Enjoy the boat. You'll have some growth on the keel when you haul in the fall but it will fall right off with the rust

Over the winter, have the boatyard remove the keel and fix it. During the summer you're likely to find some other DIY projects to keep you busy that aren't quite so daunting.

[mariner36bob]

I'm with KarlF on this one. Swing it back up and don't look at it until you have time to do it proper. When she's hauled out next fall and still in the slings drop the keel to the back of a pick up truck. It will add 30 minutes to your haul out bill. Then you'll have it laying flat on a comfortable surface to work. And you have an opportunity to address any hardware, the inside of the trunk, etc. As suggested a needle gun is what you need to remove the surface material. Remove it all. Then grind to clean metal and start from scratch. Primer, fair, barrier coat, ablative coat. You'll be glad you did it once and did it right.

[fstbttms]

Originally Posted by ryan865

However, it looks like the keel has corroded where the paint has come off.

It's not that the keel corroded where the paint came off, the paint came off because the keel is corroded underneath the paint. Know that with a big giant piece of iron hanging in the water, corrosion is likely going to be an ongoing issue. One that you may never be able to completely remedy. But that is the nature of the beast.

[ryan865]

I wanted to at least seal the open areas in order to keep the corrosion from going deeper.

So taking some of the advice from here, I got a chisel and chipped away at the worst spots. This quickly opened up some large corroded areas and even popped open a few pockets of ooze. Then I sprayed on two coats of rust converter.

The pic shows the current state of the keel, a little embarrassing. I am not sure if it was worth all the chiseling, but I feel better about putting it back into the water. Now for the paint ...

Thanks for all the help! Now I know what awaits me for the winter season.
Ryan