Northwest Dive Club

Anyone ever cleaned the (gelcoat) hull of a boat while it's in the water? This is my first season keeping my boat in the Sound, and apparently I either need to do some special paint job of the hull of pay divers to scrape the growth off once a month (I conveniently found out right after putt it in the water). Got me thinking, is this a DIY type of diving job or one better left to the professionals?

i have done it a couple times. I used a suction cup with a handle that you squeeze to make it stick then an ice scraper to scrape with. It is pretty hard work and you can't see when you start scraping the crud off. A scotchbrite pad works if it's just algae.

Interesting method with the suction cup! Sounds like a fair bit of elbow grease required.

It is Calvin, done 3 boats and you get tired quick as it's hard to move quick under water. I'm sure you will be able to do it. The last one I did had clusters of muscles that may have come off if the boat was taken out for a quick run before I cleaned it.

Well, from what they tell me it's something I'll probably have to do once a month, so now I'm leaning toward painting the hull with whatever special paint keeps the growth off of the hull. I wonder how many seasons that will last though, and if it's clear or an actual color.

Don't leave your boat in the water too long without bottom paint!! It is a huge PIA to clean once the barnacles take hold and you'll be scrubbing dime sized calcified circles off your hull for hours (take it from me - not fun!). They can actually ruin your gel coat.

Bottom painting a boat is no small task - I did my previous boat and it took me the better part of a week.

There are two types of anti fouling pained - Ablating and non-ablating.....

Ablating paint is chalky and sluffs off so barnacles and marine life cant adhere to it. It's easier to apply but it wears off eventually and needs to be redone once every 1=2 years. The bad thing about the ablating is that if you trailer your boat as well the chalky ablating paint gets all over everything. Plus I think it only comes in rust and blue colors.

Non-ablating keeps the critters off your boat using a hard copper impregnated paint that looks similar to rhino liner. It requires sanding your hull below the water line and applying 5 coats of hull sealer and then 3 coats of paint, but it lasts much longer (about 3 - 5 years) and it's not nearly as messy.

BillZ wrote:Don't leave your boat in the water too long without bottom paint!! It is a huge PIA to clean once the barnacles take hold and you'll be scrubbing dime sized calcified circles off your hull for hours (take it from me - not fun!). They can actually ruin your gel coat.

Bottom painting a boat is no small task - I did my previous boat and it took me the better part of a week.

There are two types of anti fouling pained - Ablating and non-ablating.....

Ablating paint is chalky and sluffs off so barnacles and marine life cant adhere to it. It's easier to apply but it wears off eventually and needs to be redone once every 1=2 years. The bad thing about the ablating is that if you trailer your boat as well the chalky ablating paint gets all over everything. Plus I think it only comes in rust and blue colors.

Non-ablating keeps the critters off your boat using a hard copper impregnated paint that looks similar to rhino liner. It requires sanding your hull below the water line and applying 5 coats of hull sealer and then 3 coats of paint, but it lasts much longer (about 3 - 5 years) and it's not nearly as messy.

Wow, this is very helpful information! Do you happen to know of a good place on the sound (moored in Seattle) to have this work done? I was quoted $75-125/foot (boat length) by a place up in Edmonds. They did mention sanding so I'm hoping it was for the second method you wrote about, though they said it was only 2 or 3 coats ($75 vs $125).

Another option...
I've never done it but some people I know will bring their boat into to Lake Washington every 3-4 weeks and leave it for a couple of days. From what I've been told the fresh water will kill the growth and then you can scrub the hull with a deck brush and it will be as good as new.

Tangfish wrote: Wow, this is very helpful information! Do you happen to know of a good place on the sound (moored in Seattle) to have this work done? I was quoted $75-125/foot (boat length) by a place up in Edmonds. They did mention sanding so I'm hoping it was for the second method you wrote about, though they said it was only 2 or 3 coats ($75 vs $125).

Sorry - I don't know anybody that I can recommend. Ping Richard (captnjack) and see if he knows someone, he's a wealth of information on stuff like this.

$75 -$125 sounds about right - I think I was quoted $3k for my 26ft boat when I called around.

2 - 3 coats is more than likely only the antifouling paint itself. With the non ablative bottom coats you also need to apply a barrier coat between the gel coat and the paint or you could have problems with it adhering.

BillZ wrote:Ping Richard (captnjack) and see if he knows someone, he's a wealth of information on stuff like this.

Pinging him now!

This is way more involved than I anticipated. N00b indeed

You want to be careful where you choose to do it. It is illegal in most marinas. You can get a hold of Mike Roth over in Port Townsend and see if he is still doing it. They can do it for you at the port. They have hydro equipment and do it out of the water hanging in a sling so you can see it all. they can handle anything up to 100 tons

Bill pretty much covered bottom paints. I would like to add that marinas are a dangerous place to dive. Stray electrical current kills. It is most dangerous in fresh water.

If you have done so yet you want to make sure you check your zincs. Some marinas are hotter than others. A hot marina will eat zincs faster.

Yes, I am just now putting new zincs in. Dusty2 did you mean diving is illegal? I've already decided to go the bottom paint route. Just gotta figure out if the place I've talked to about it is good and a decent price.

I clean my parents hull (bottom painted) about twice a year. Zinc replacement I usually only have to once a year. Used to be more often when more stray current was around in the marina.

I will be scrubbing and zincing this weekend. It is a strenuous job. (42' sailboat).

Tangfish wrote:Yes, I am just now putting new zincs in. Dusty2 did you mean diving is illegal? I've already decided to go the bottom paint route. Just gotta figure out if the place I've talked to about it is good and a decent price.

No I mean bottom cleaning. The EPA and DNR have very strict rules about where it's legal to do bottom cleaning. Be sure that the outfit you hire is using EPA approved paint and that they are licensed to do it.

I put my boat in the salt water every summer for the past four years. I do not have bottom paint. I use three coats of marine paste wax at the start of the season, when it is out of the water. I scrub it with a stiff brush about every 5 weeks when it stays in the water. The big difference is the covered slip. If your boat is not kept in the shade the growth will come on strong. I used Starbrite Hull cleaner when the boat is on my trailer to clean barnacle spots. It works great to take stains out and clean calcium spots.

The hard bottom paints will eventually leach away all their copper and the residual epoxy matrix will need to be sanded off. Its a bear to do. Still I would go with a hard paint, its much more environmentally friendly and lasts longer. ~100ft a foot for prep, and paint is about right. If you can dry store your boat you will avoid this whole problem and won't need any paint at all.

It is prohibited to scrape a soft ablative bottom painted boat in the water. That's how marina sediment get (seriously) contaminated with copper.

Well, she's already moored where she is (in the water) for the season. Other than these extra considerations it's a great place to be. Hopefully this bottom paint will last a couple-few seasons. If this is a once a year type thing then this'll be my only year in the Sound, even though it's been great so far!

So after thinking this over I'm going with two coats of the non-ablative hull paint. They said it should last 2-3 seasons. I don't keep the boat in the water all year though, which might help a little. They also recommended painting the sterndrive, which is another 6 scuba units. They said that's optional though. Should I do it fellas?

If your boat is an inboard/outboard then for sure paint the stern drive. If its an outboard and you can lift the motor out of the water then you'll be ok without it.

Tangfish wrote:So after thinking this over I'm going with two coats of the non-ablative hull paint. They said it should last 2-3 seasons. I don't keep the boat in the water all year though, which might help a little. They also recommended painting the sterndrive, which is another 6 scuba units. They said that's optional though. Should I do it fellas?