My boat stays in the water year round in a freshwater lake in Georgia. I The bottom redone in November of 2000 (I bought the boat last August) and at that time was stripped, barrier coated with Interprotect 2000 and painted with Bottomkote. Diving on the bottom of the boat this summer and winter shows some blisters that appear to be only in the bottom paint (i.e. underwater I can pick the blister with my fingernail and small pieces flake off. I know the bottom is definitely due for a bottom job, but my question is should there be any hurry to do it? The only growth that happens here is algae, which I scrub off once a month. Does the bottom paint add any "structure" or protection to the hull other than to discourage growth? I'd like to wait one more season, but I'm a bit nervous to do so since it seems that everyone does a bottom job every year or two. Thanks for any insight.
Ryan
Bottom paint necessity
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Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
- Location: Whitefield, ME
- Contact:
Bottom paint performs no real function other than to discourage (with marginal results) the growth of serious marine creatures.
In fresh water, the algae/slime tends to form with or without bottom paint, and you don't need it in the sense that it's needed in salt water. You don't even technically need it in salt water if you cared to come up with other ways to keep the growth off the bottom, but the paint truly does make a difference in salt water. Boats without it grow alarming things in very short periods of time.
No harm will come to your boat if you don't repaint the bottom at once. You might see a decrease in the need to scrub it if the paint was fresh, but you might not either. Water getting behind old bottom paint is very common, and it tends to force it to flake away. This problem will exacerbate until bottom prep and recoating occurs.
Note that damaging fiberglass blisters do not form in fresh water. True blisters require the chemical reaction formed between salt water and the styrene in polyester resin. This doesn't mean that there was a pre-existing condition from a time when the boat was in salt water.
In fresh water, the algae/slime tends to form with or without bottom paint, and you don't need it in the sense that it's needed in salt water. You don't even technically need it in salt water if you cared to come up with other ways to keep the growth off the bottom, but the paint truly does make a difference in salt water. Boats without it grow alarming things in very short periods of time.
No harm will come to your boat if you don't repaint the bottom at once. You might see a decrease in the need to scrub it if the paint was fresh, but you might not either. Water getting behind old bottom paint is very common, and it tends to force it to flake away. This problem will exacerbate until bottom prep and recoating occurs.
Note that damaging fiberglass blisters do not form in fresh water. True blisters require the chemical reaction formed between salt water and the styrene in polyester resin. This doesn't mean that there was a pre-existing condition from a time when the boat was in salt water.
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Thanks Tim. This is what I expected, but it is nice to hear it from someone else to reinforce the point.
The boat has been in fresh water since new (1982) so I suspect that the bottom job don in 2000 was in response to superficial gel coat blisters. The previous owner just had the marina do whatever they thought they needed to do to the boat, so at least I have decent documentation as to what was done, even if I have to spend time redoing a lot of it. Thanks again!
Ryan
The boat has been in fresh water since new (1982) so I suspect that the bottom job don in 2000 was in response to superficial gel coat blisters. The previous owner just had the marina do whatever they thought they needed to do to the boat, so at least I have decent documentation as to what was done, even if I have to spend time redoing a lot of it. Thanks again!
Ryan