Bottom paint

[jj]

We are expecting delivery of a new NC895 Sport soon and although the boat will be lift kept mostly there will be stretches of time from several days to a few weeks where the boat will always be in the water while cruising. We are in Florida (saltwater). I am thinking we should go ahead and have bottom paint (Petit Hydrocoat) applied and possibly even a barrier coat as well. A friend has told me this can decrease the boat’s value for resale. Any thoughts would be appreciated. 

[Don Reaves]

The usual advice regarding bottom paint is to find out what people in your area are using, and whether they are happy with their choices before making a decision. My experience is with sailboats, where a barrier coat is essentially a requirement. I don't know whether it would apply to your boat as well.

The idea that applying bottom paint might reduce resale value is something that would never have occurred to me. However, I would fall back to that same advice. Check with others in your area. If nobody paints the bottom, there might be a perception that it's a negative, and might reduce resale value in your area.

[jj]

Thanks for your reply. We have a sailing background and understand the necessity of bottom paint for the sailboat. The fast powerboat thing will be all new and hence the questions. I will talk to local powerboaters about their choices. 

[jweller001]

Under what circumstances will removing bottom paint result in a new barrier paint being required? Under my brown Micron Extra, I see some blue and some white layers and wondering if removing the bottom paint with chemical stripping or sanding will damage the barrier paint forcing a complete bottom job?

[Don Reaves]

First, let me say that I'm not an expert on this subject, so others may give you a better answer.

It is my understanding that if you remove the barrier coat, you should repair it before applying bottom paint. If it's a very small area, maybe it could be overlooked. Repairing the barrier coat can be done only in damaged areas, so it doesn't mean doing the entire boat.

My experience was 30 years ago, when I used a carbide scraper to remove years of a hard epoxy-based paint. It was very difficult not to go through the barrier layer in various places. To be on the safe side, I removed all of the old bottom paint and applied the recommended number of layers of epoxy barrier before applying the new bottom paint.

Since you are seeing different colors, you can use this as an indication of how much paint you are removing. Assuming the old paint is compatible with the paint you want to apply, you should only remove enough to get a surface that will allow proper adhesion of the new paint. So you might want to stop when you see almost all blue, for instance, knowing that you haven't damaged the white layer. I'm pretty sure this is possible with either sanding or chemical strippers, but you will need to be careful when doing it.