Steel Hull corrosion

[PasosLargos]

I have a steel hull boat with a full keel. I just bought her and painted her but I had a difficult time painting under her keel. A man at the local marine supply shop told me I didn't need to put an epoxy primer on her, so I didn't. I just sanded her and painted her bottom side.

There were two places under the keel that I could not get to because the boat had two wooden blocks under her while on the hard. I'm concerned about these areas and under the keel in general.

Do I need to worry about bottom growth and corrosion under the keel? Can I afford to keep her in the water a few more months or should I pull her out and fix it right away?

Thanks for your help.

[fstbttms]

In short, I think you got some bad dope from the guy at the marine supply shop. You definitely wanted to have a barrier coat everywhere and yes, corrosion and fouling are likely going to be issues in the unpainted spots.

[grantmc]

What fstbttms said. But also the spots on the blocks need to be painted. No urgency, a few months won't hurt. So need to stress.
Normally I would be on hand with anti foul paint and brush when the boat is getting lifted to return to the water. And I paint the obscured spots then. Yard staff are used to people doing that. And the paint stays on in the water.
Some people go the extra mile and have the boat moved slightly. This may cost an extra lift.

[fstbttms]

Originally Posted by grantmc

Normally I would be on hand with anti foul paint and brush when the boat is getting lifted to return to the water. And I paint the obscured spots then. Yard staff are used to people doing that. And the paint stays on in the water.

Yes unfortunately, paint requires exposure to air to cure properly and when you splash a boat that has wet paint, that doesn't happen.

[PasosLargos]

Originally Posted by fstbttms

In short, I think you got some bad dope from the guy at the marine supply shop. You definitely wanted to have a barrier coat everywhere and yes, corrosion and fouling are likely going to be issues in the unpainted spots.

The boat already had a coat or two of primer and paint from years past. I'm not sure if that will help though.

[barnakiel]

I always use epoxy on steel, before I apply any paint.


The blocks are moved either by lifting the boat on a jack, or else on a travelift.


b.

[RaymondR]

Happens all the time and provided you have anodes on the hull it does not cause corrosion problems.

Provided the bottom plate is pretty solid you can minimize the area affected by making up a couple of triangular stands by welding a piece of 4" X 4" X 3/8" angle iron onto a piece of plate. needs to be long enough to extend outside the keel on both sides.