Fiberglass bottoms and divers

[Jack Long]

How solid an assessment of the underside of a boat do you get from a diver relative to having the boat hauled out?

I read about a lot of "haul out every 3 years" strategies. With a fiberglass boat that had semi regular diver service but spent a lot of time in the slip (most of the year) how long could it go before it started to have real problems from not getting fresh paint?

I heard the following quote the other day "I grew up in a sailing family and we never painted our fiberglass boats- we just used divers" and it set some alarms ringing in my mind.

Thanks,
J

[edboat]

My feeling is that you need at a minimum a good epoxy barrier coat to protect the gelcoat.Gelcoat is much more porous than most people think. If you can keep it clean great, but in warm saltwater you will be cleaning the boat every few weeks.

[ssullivan]

Originally Posted by edboat

My feeling is that you need at a minimum a good epoxy barrier coat to protect the gelcoat.Gelcoat is much more porous than most people think. If you can keep it clean great, but in warm saltwater you will be cleaning the boat every few weeks.

I hear that! (literally)

I'm stopped at an anchorage right now, getting ready to take off for the day and it's very quiet.

Instead of the normal little click, click here and there you hear from hull growth, I'm hearing what could almost be described as television static. That's how many buggers are down there building cities on my hull right now in FL.

Got to get where there is some tide so I can scrape some off!

[Pblais]

How solid an assessment of the underside of a boat do you get from a diver relative to having the boat hauled out?

As far as the condition of your bottom paint goes a diver should be able to tell you when the anti fouling is not working well. I haul every other year. I can't get ablative paint to last more than that. The summer brings very warm water here. The colder the water the slower the stuff grows.

[Jack Long]

Well, the water here is pretty cold...

Uh, I don't think my concern was clear. If the boat hasn't been painted in longer than it should be- does this just mean that growth will accumulate faster? Or does it mean DAMAGE to the bottom of the boat? Like, a good scraping and paint and back in business or...?

Thanks!

[dcstrng]

Originally Posted by Jack Long

Well, the water here is pretty cold...

If the boat hasn't been painted in longer than it should be-

I’d like to know that answer as well… We got our little rascal after it had been sitting at an unattended mooring for something like four-five years… of course the bottom had developed into its own eco-system over that many years, but one thing I noticed is that what few blisters I found (and one 4” delamination area that had to be ground out and reglassed…) were in areas where the bottom paint was nonexistent… whether that was due to uneven coating in the last painting, or what I don’t know, but I’m wondering if garden-variety bottom paint doesn’t in some way influence skin protection… didn’t find more than about 4-6 actual blisters (as well as some old repairs that didn’t look well done – looked like they’d used bondo instead of WEST or equivalent,…), but inevitably the new ones were in areas where it was only bare fiberglass…

[Pblais]

If the boat hasn't been painted in longer than it should be- does this just mean that growth will accumulate faster?

The barrier coat protects the bottom and the anti fouling prevents the growth. At some point the tremendous amount of growth could enter into the picture. At the very least the performance will suffer greatly from the weight and the friction.

The issue of blistering is the infusion of water and I doubt seriously that anti fouling paint adds much protection. The barrier coat is the key. Blistering can also be a function of the material used to make the boat. The years in the very early 1980's when we had the first oil crisis had a lot of boats that didn't fair well with age due to the poor quality resins being sold on the cheap back then. There is a limit to what a barrier coat can protect you from when what is under it isn't very good to start with.

[island trader]

jack, the paint will not protect the boat bottom, just slow growth. I have seen boats pulled without paint of any kind here in the south, and after lots of chipping off the oyster growth, the bottom looked like one with paint. we have strong tides and they coat the bottom with mud and that helps, almost as good as paint.

[David M]

In my experience divers can find things that are wrong. But a haulout can reveal things that a diver might miss. Haulouts are better but of course more expensive. You get what you pay for here.

How often you need to paint partially depends on where you live and what species of critters like to attach themselves to your hull.

[Nightwatch]

I am in FL and can go 3 years with 2 coats of the best bottom paint you can buy. That is also the most expensive. I have the bottom scrubbed quarterly. I am in need at 3 years, but it is not bad. It takes 3 ears for the man who does the work and myself to get back on civil terms.

The hull was laid up in 1978. When I bought her she had been abandon for 5 years and no one new when the last bottom job had been done. After 4 weeks in the yard we found 50+ blisters with the largest being the size of a quarter. Since repairing those, we have found maybe 3 or 4 more in the past 12 years.

To do a good epoxy coat, you should grind off the old gel coat and allow the hull to dry out. That is expensive and can be very time consuming. If there is a blister problem with the boat, (Many, Large and Deep) then it should be done. Some boats are more prone then others. The original cost of the boat does not seem to have much to do with it blistering. A good surveyor should be able to tell you about the reputation of your boat.

[AnchorageGuy]

Originally Posted by edboat

My feeling is that you need at a minimum a good epoxy barrier coat to protect the gelcoat.Gelcoat is much more porous than most people think. If you can keep it clean great, but in warm saltwater you will be cleaning the boat every few weeks.

No epoxy barrier, boat is in the water 24/7/365 and no gelcoat or blister problems. Oh did I mention the boat is almost 30 years old. We have a diver clean the bottom or clean it ourselves every couple of months if we are at the dock for long periods. If we are cruising the bottom MIGHT get cleaned every six months. We haul out and re-paint around every two years and some times longer. Warm Saltwater is always the order of the day. On haul outs the bottom is usually in pretty good shape and on occasion we get ask why we are repainting. We use Pettit Trinadad.

[AnchorageGuy]

Originally Posted by ssullivan

I hear that! (literally)

I'm stopped at an anchorage right now, getting ready to take off for the day and it's very quiet.

Instead of the normal little click, click here and there you hear from hull growth, I'm hearing what could almost be described as television static. That's how many buggers are down there building cities on my hull right now in FL.

Got to get where there is some tide so I can scrape some off!

Sean, What you hear are shrimp under and around the boat not critters building anything so don't worry about cleaning the bottom. get out the shrimp nets and prepare for dinner.