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Bottom Paint for Bare Hull
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| Gholby |
Posted on 05/14/10 - 4:45 PM
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I have a Dauntless 14 that has never been painted. I need to paint it as it will be kept on a mooring in Maine. Any suggestions as to paint and preparation? Thinking of going with an ablative and I guess I will need to either prime or sand first.
Thanks
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| ioptfm |
Posted on 05/14/10 - 6:33 PM
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I used an ablative on mine and have been pleased with the results so far. Remove any wax that may have been applied and it's not a bad idea to rough it up a little for adherence. I don't think it would be necessary to prime it first if you have the surface free of oils and wax.
Tom
1979 Sport 15' |
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| John Fyke |
Posted on 05/14/10 - 6:51 PM
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You need to sand where you will be putting on bottom paint or you will have adhesion problems.
John Fyke
Re-Fit or Reef It
1979 15' Sport with Super Sport conversion and 70hp mercury. |
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| number9 |
Posted on 05/14/10 - 11:27 PM
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Prior to the wide spread availability and use of barrier coats to help prevent blisters the standard prep for bottom painting was to roughen the gelcoat. When the blister problem became well known many attributed the blisters on susceptible hulls to the prep actually making the gelcoat more permeable. I would recommend not sanding and using a no-sand primer or if you do sand use a two part epoxy barrier coat.
Bill...On the Ogeechee
1984 Outrage 18...Yamaha T50...that's right, 50hp |
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| drandlett |
Posted on 05/15/10 - 3:45 AM
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I keep my boat in the water in Maine from begining of May to middle of October and use ablative paint and am very pleased with results. I use Petit Hydracoat, inexpensive, easy to work with and requires very little work.
When I first painted my bare hull several years ago I simply scuffed the bottom from waterline down, just kiss it with 80grit to give her some tooth. If I were to do it all over again I think I use a coarse 3M scotch brite pad instead of sandpaper.
I also work at a boat yard (after I first painted mine), and we use Hydracoat on all hulls except performance sailboats and some yachts where captains will have boats in warmer water much of the year.
Thats my experience, good luck and happy boating. I keep my boat in Casco Bay where will you be?
Dana
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| Gholby |
Posted on 05/15/10 - 6:47 AM
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Thanks very much for the advice. Good to hear that the Hydracoat is effective - that was another question I had.
Gard
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| Tom W Clark |
Posted on 05/15/10 - 7:00 AM
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Before applying bottom paint, you really should apply an epoxy barrier coat to the bottom.
Follow the instructions precisely, they are important.
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| ioptfm |
Posted on 05/15/10 - 9:28 AM
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Tom W Clark wrote:
Before applying bottom paint, you really should apply an epoxy barrier coat to the bottom.
Follow the instructions precisely, they are important.
Tom. what is the purpose of the epoxy barrier coat? gel coat protection, adhesion? Not heard of that before
Tom
1979 Sport 15' |
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| John Fyke |
Posted on 05/15/10 - 10:14 AM
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Epoxy helps with adhesion and at certain mil thinkness it would be waterproof.
Edited by Joe Kriz on 05/15/10 - 1:06 PM
John Fyke
Re-Fit or Reef It
1979 15' Sport with Super Sport conversion and 70hp mercury. |
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| jollyrog305 |
Posted on 05/15/10 - 4:13 PM
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I posed somewhat of the same question on the other forum:
“So here is a follow on question – if using an antifouling paint like Micron Extra, do you need to prime/seal the hull first to prevent blistering, or will the Micron do that as well, even though it will eventually wear off and need repainting (Micron says you can put it directly on a bare/dewaxed hull)?”
So I emailed Micron and they emailed me back and said that the 2 coats of Extra on a bare hull will not guarantee against blistering and recommended sealing/priming it first. This was the same suggestion from the dealer this year – although they just repainted the bottom last year (and there was a lot more wear than this year – i.e. you could see bare hull after the power wash - ??????). I was a bit confused (and upset quite frankly) so they put some heavy coats on this year and I will address it when I pull the boat…
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| John Fyke |
Posted on 05/15/10 - 5:13 PM
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jollyrog305 wrote:
I posed somewhat of the same question on the other forum:
“So here is a follow on question – if using an antifouling paint like Micron Extra, do you need to prime/seal the hull first to prevent blistering, or will the Micron do that as well, even though it will eventually wear off and need repainting (Micron says you can put it directly on a bare/dewaxed hull)?”
So I emailed Micron and they emailed me back and said that the 2 coats of Extra on a bare hull will not guarantee against blistering and recommended sealing/priming it first. This was the same suggestion from the dealer this year – although they just repainted the bottom last year (and there was a lot more wear than this year – i.e. you could see bare hull after the power wash - ??????). I was a bit confused (and upset quite frankly) so they put some heavy coats on this year and I will address it when I pull the boat…
Is your boat moored for a long period of time? If not don't worry.
John Fyke
Re-Fit or Reef It
1979 15' Sport with Super Sport conversion and 70hp mercury. |
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| A Little Madness |
Posted on 05/16/10 - 5:37 AM
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I'll keep it real simple - Petit Trinidad SR (Slime Resistant). We keep 2 boats in the water year-round in southeastern NC. We just pulled our 41 year old Alberg Typhoon out after a 1 1/2 years in the water and she didn't need repainting. We do have someone dive on her every quarter so there were no barnacles either. Point is, SR is a fantastic paint. We use it on our Little Madness as well with the same results. Good Luck!
Chris & Dale Schnell
"A Little Madness" - 1989 Montauk 17' |
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| jollyrog305 |
Posted on 05/16/10 - 9:23 AM
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March to November - to date haven't had any blister issues (knock on wood). I know there are many factors that must be present/contribute to hull blistering Like I said this is how it was delivered from the (original) dealer, recoated the same way last year (from another dealer) and then recoated again this year (when it was discovered that there was not any sealer). Again, if it was put on incorrectly again and again over the years - it has been done by two separate dealers...
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| Tom W Clark |
Posted on 05/16/10 - 9:27 AM
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Epoxy barrier coats seals and protects the hull against water absorption and osmotic blistering, not as an aid to adhesion; bottom paint sticks just fine to gelcoat.
Barrier coats have been pretty much de riguer for the last decade or two.
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| tedious |
Posted on 05/17/10 - 4:53 AM
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If you go to any paint manufacturers website you'll find more than you need to know about bottom painting. As others have mentioned, you need a barrier coat, then a topcoat of antifouling. Some people have mentioned ablative paint and I am sure that is needed in some southern areas, but in Maine you may be able to get away with a hard-finish epoxy, which may be more durable. We use Pettit Unepoxy Standard and we get a couple of years out of it, on a boat that's at a mooring in Boothbay Harbor from mid-May through September.
One trick is to make the first coat of bottom paint in one color and the second coat in another - that way when you see the color change you know it's time to repaint. Also, for being on a mooring, be sure to check the zincs - we go through a set of trim tab zincs in a summer.
Tim
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| John Fyke |
Posted on 05/17/10 - 8:55 AM
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Tom W Clark wrote:
Epoxy barrier coats seals and protects the hull against water absorption and osmotic blistering, not as an aid to adhesion; bottom paint sticks just fine to gelcoat.
Barrier coats have been pretty much de riguer for the last decade or two.
Regardless of epoxy as an aid to adhesion it still is.
John Fyke
Re-Fit or Reef It
1979 15' Sport with Super Sport conversion and 70hp mercury. |
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| mattgeiger |
Posted on 05/17/10 - 11:16 AM
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I've done a few barrier coats on blowboats here. The running joke is that Lake Lanier will blister a concrete block. I've used Interlux 2000. The stuff is the most difficult thing I have ever had the displeasure of making smooth (removing the orange-peel) after applying. I have seen it work well - as long as you're starting with a dry hull. Osmotic blisters can form from within as well. And as far as adhesion - I consider interlux 2000 a great high build primer.
Edited by mattgeiger on 05/17/10 - 11:20 AM
Cape Dory 28
Hobie 20 Miracle
A Class Catamaran |
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| number9 |
Posted on 05/17/10 - 1:31 PM
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Regardless of epoxy as an aid to adhesion it still is.
Barrier coat aid to adhesion? Yes on metal hulls. Maybe on fiberglass? Compared to what other prep and? Have there ever been any tests done?
Keeping in mind cured 2-part epoxy paints are slicker than gelcoat and most other primers, referring to it as an aid obviously will lead to some disagreement. If the barrier is not top coated within it's recommended time period then sanding to provide adequate adhesion should be done.
Bill...On the Ogeechee
1984 Outrage 18...Yamaha T50...that's right, 50hp |
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| John Fyke |
Posted on 05/17/10 - 1:34 PM
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number9 wrote:
Regardless of epoxy as an aid to adhesion it still is.
Barrier coat aid to adhesion? Yes on metal hulls. Maybe on fiberglass? Compared to what other prep and? Have there ever been any tests done?
Keeping in mind cured 2-part epoxy paints are slicker than gelcoat and most other primers, referring to it as an aid obviously will lead to some disagreement. If the barrier is not top coated within it's recommended time period then sanding to provide adequate adhesion should be done.
I have been a Paint Technical Rep for 16 years. I have forgotten more about paint than you know.
John Fyke
Re-Fit or Reef It
1979 15' Sport with Super Sport conversion and 70hp mercury. |
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| albert |
Posted on 05/17/10 - 4:12 PM
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i would sand it first,
cleen it a little and then prime
for the gelcoat i would do a clear white (whaler only)
but from 1995 to 2005
those are one of the best
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