bottom paint flakes

[Fred W.]

My botton paint has a few spots where a layer of paint has flaked off. Probably not sanded properly in the past prior to painting. Sanding and painting over top is OK but leaves a bit of an indentation in the flaked areas. Is there any kind of a putty or something that you can fill the flaked area and sand smooth prior to re-painting. I know I could strip all the bottom paint off and start again but it's not bad enough to do that...yet.

 

[Dan McGuire]

What kind of Paint?

Some polyurethane paints will flake when continuously under water. The type of paint may dictate whether it should all be removed or just feathered, filled, etc.

 

[Fred W.]

Interlux Micron CSC

Interlux Micron CSC

 

[Dan McGuire]

Interlux Micron CSC Should be OK

I probably depleted my knowledge when I asked the first question. If it was me, I would do more sanding and see if the rest of the bottom paint adheres properly. If it does you might try sanding the spots down to the fiberglass and applying a primer and barrier coat. The barrier coat should have good filler qualities.

 

[Peter J. Brennan]

Moonscape

Having the same flaking problem now. Boat has always had ablative (CPC50) on it and looked really good year to year. But now some of the very frist layer is showing lack of adhesion leaving no-paint spots and a crater a few millimeters thick. Complete removal and start from scratch is not an option. Did that once and never again. Best thing is to remove any loose paint, feather the edges of the craters and apply new pain to a throuroughly scuffed fiberglass surface. Seems to me if you apply a barrier coat in the craters to bring the surface up you will eventually have a whole lot of little plateaux all over your bottm.

 

[Dan McGuire]

Barrier Coats

I should have mentioned it, but one of the reasons I suggested a barrier coat, was the possibility of creating new blisters when going all the way down to the fiberglass. Probably not a major problem. No solution is perfect.