What paint for below waterline????

[Porkchunker]

I started a thread entitled: Marine Painters in the Annapolis area???? and received some great guidance. Based on that guidance, I decided to try to paint the boat myself.

However, during my research on applying marine paints (both spray and roller/tip methods), I discovered that all the paints I encountered had the following caveat: "not for below waterline."

So...what kind of paint would you put on this 16' runabout/flyfishing hull that is not in a slip, and when on the water, probably only stays on the water for 6-12 hours at a time. I believe I've overnighted on the beach once (anchored bow out and tied the transom to a tree), so in those instances, it is in the water a max of 36 hours. The rest of the time she sits on a trailer in the garage under a canvas cover.

I went to the local BoatUS shop at lunch and checked out some paints. All had the caveat. The Pettit "Easypoxy" single part Poly stated that it could be used below the waterline for no longer than 48 hours of exposure at a time. I'm a little hesitant to use that, even though I'd probably never get to a full 48 hours on the water in a single fishing trip.

Any other options that could go down on top of Imron?

Porkchunker: http://thebayguide.com/rec.boats/skopje179.html

[kc8pql]

The cautions are for boats that live in the water. For the short times you're talking about, use anything you want.

[maa. melee]

Porkchunker, may I have your email to send you info on a paint?

[ 02-27-2006, 08:25 PM: Message edited by: maa. melee ]

[Les Schuldt]

Chunker,

I raised a similar question a couple weeks ago. My boat is a lapstrake plywood boat and I'm going with Interthane Plus 2 part LPU both above & below the waterline. There's a lot of good opinions in that string. Hava look.
http://www.woodenboat-ubb.com/ubb/ultim atebb.php?ubb=get_topic;f=1;t=013020 (http://www.woodenboat-ubb.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=013020)

[ 02-27-2006, 08:27 PM: Message edited by: Les Schuldt ]

[Mike Vogdes]

How bout something that looks really good and is easy? Cost about 150 - 200 bucks and will be finished in a weekend..
No muss, no fuss, just do a little fairing and pass some sandpaper over what you have followed with a few coats of Kirby's....

[Thad Van Gilder]

kirby's is my fav.

-Thad

[Thorne]

Unlike Les ( who lives nearby and been very helpful) I'm looking for a cheaper alternative for my trailerable fir over oak dory. Unlikely that the boat will ever spend more than 2 days in the water at a time.

I'm wooding the outside, reefing out the sealant/caulking (probably 5200) between the laps, coating with CPES and re-caulking with Vulkem 116.

So given that prep situation, what primer and paint?

I'd prefer to go with an oil-based solution for both, but am open to water-based if necessary. Unable to take Bob S's excellent recommendation for the Kelly Moore floor paint as they don't sell it in California.

Would love to keep the cost under $90/gallon, prefer more like $50/gallon -- and a gallon will be WAY more than I need.
http://www.luckhardt.com/scraper1.jpg

No need for anti-fouling paint, although I am using an ablative on the false bottom of knotty fir over the real bottom planks. Will paint it over the bottom paint if I find it necessary, otherwise just using it on the false bottom.

[ 02-28-2006, 09:50 AM: Message edited by: Thorne ]

[Porkchunker]

maa,

skopje180@earthlink.net

Porkchunker: http://thebayguide.com/rec.boats/skopje179.html

[ 02-28-2006, 02:25 PM: Message edited by: Porkchunker ]

[almeyer]

My little 14-footer is built glued ply lapstrake, and lives on the trailer in the garage. When I sail, I very seldom see freshwater, but I rinse it off each time after sailing before I put it up. I sealed the ply with thin epoxy, followed by two coats of topside primer and two coats of topside paint. Launched in 2004, so far I haven't seen any problems, but don't expect any either since it spends most of it's time out of the water.
For what it's worth.
Al

[Porkchunker]

Wow...I just chased some of the links provided and I'm now more disappointed than before.

Topside paint will blister if left in the water for more than a couple of days, or if the bunks hold moisture.

I still haven't come across a paint that can be truly used on the bottom without fear of blistering. I thought Awgrip was one tough hull paint, but it also has the caveat: "not for use below the waterline."

What about the 2-part epoxy paints? Interthane Plus came up in one of the responses.

What is a guy to do?

Porkchunker: http://thebayguide.com/rec.boats/skopje179.html

[Thorne]

Oh woe is us!

;-0 )

Porkchucker -- I'm guessing that the "not below the waterline" text you are encountering is all legal CYA stuff, and that for trailerable boats that are mostly day-use, the good-quality paints will work fine.

Al -- I take it that you used marine grade topsides primer and paint -- what brand?

I'm tempted by the Rustoleum marine-grade topsides primer and paint -- the primer is high-fill and weighs nearly as much as a can of Kirby's red lead.

[seo]

A very good paint that might work is Pettit Rustlok steel primer. It's very hard, shiny silver, penetrates well, and if you get it on your hands you will have silver spots until the skin sloughs off. Which suggests that it adheres well. Over that you could put one of those glossy hard racing bottom paints. Not terribly effective as an anti-fouling, but this is a trailer-boat, right?
Or paint it with the latex intended for use on cement block walls. It might not stick, but it would be no great loss if it didn't.
seo

[almeyer]

Thorne, I used West Marine house brand, as it was on sale at the time. I doubt there's very much difference between it and any of the "name brand" such as Interlux.
My bunks are scraps from old carpet, which made for a cheap covering, but retains moisture longer than I'd like. But so far I haven't noticed any blistering on the paint.
Al

[John Turpin]

I hadn't thought about bunks holding moisture, but that's an interesting problem. I could see how prolonged exposure to wet carpet could affect paints.

It should be possible to replace the trailer bunks with something that dries more quickly. Maybe replace the wood with some of that new plastic porch decking material and wrap it with astroturf. That wouldn't cost more than $20 or so at Home Depot. I may do that.

As for paints, I read many articles/comments on the use of porch paint on boats. I painted my pram with a good porch paint last year and was not pleased with the result. It looks great, but a little effort with a thumbnail takes it right off.

[Thorne]

Actually I'm more concerned about the Rustoleum marine high-base primer than the marine enamel -- I figure that marine-grade oil-based paints should be relatively similar and OK for trailered wood hulls.

The primer is semi-liquid putty-in-a-can, also oil-based. Anybody know of any risks to use something like this below the waterline? The planks are fairly uneven, a bit checked, and the copper nailheads also uneven -- it really needs some sort of leveling / fairing before being painted. Again, it will be applied over a coat of CPES, which I hope will improve both the life of the planks and adhesion of primer/paint.

Regarding the concerns about moisture in the trailer bunks, another thread on this forum mentioned a cute trick -- keel-rollers that can be winched/raised and lowered easily.

The forumite said he trailers with the rollers down, but when home he raises them for a few days to make sure the bunks and hull dry out -- then lowers the rollers.

Too expensive for my budget home-made trailer, but might work for Porkchucker?

[ 03-01-2006, 09:53 AM: Message edited by: Thorne ]

[Wild Wassa]

How about Dupont's Imron?

What is on your boat now? ... over the glass I mean.

How long has it been on the boat?

Has what is on your boat done the job?

(So many questions so few options).

There is no time like the present to learn to paint.

Warren.

[ 03-02-2006, 08:49 AM: Message edited by: Wild Wassa ]

[pipefitter]

If you use thick, semi liquid, high build primer to fair nail spots with,you better wait months for it to shrink up because it will expose everything after it's painted. High build primer,although very thick is only meant for the most minor scratches and imperfections.Some primers actually show imperfections worse. There is a gremlin in the paint trade called "sand scratch swelling" where the primer actually amplifies the sanding scratch marks.More prominent with spray application fast dry solvent based primers.If you use that thick stuff,be prepared to sand it to a semi transparent condition.If you use the oil based primer over epoxy systems,it better be very well keyed and free of even a trace of amine blush.

If you are using CPES,you might as well go the extra step and use regular thin epoxy as your fairing base over the CPES.That would be a much better primer than the oil based.

[ 03-02-2006, 10:56 AM: Message edited by: pipefitter ]

[Thorne]

Interesting!

Hope we haven't totally hijacked Porkchucker's thread, but it all seems to apply.

I'm using Smiths Cold Weather formula CPES, and can purchase more of his two-part epoxy fairing compound.

I was under the impression that the high-fill primer by the same paint company would be a better match for the marine-grade paint than an exoxy primer/fairing compound. Smith recommends using CPES over the fairing compound before painting anyway...hmmmmmm.

Whatever high-fill primer was used previously on these fir planks has held up very well -- tough to get off even with a heatgun and good scraper. The paint was Waste Marine's topsides enamel, which comes off better/held worse.

Not to second guess, but is this a general consensus that epoxy fairing compound is better than marine-grade high-fill primer under the same brand's marine-grade enamel? Unlike Porkchucker, I'm not going for a professional-look yacht paintjob -- my boat is a workboat just tarted up a wee bit with some brightwork.

;-0 )

[ 03-02-2006, 11:24 AM: Message edited by: Thorne ]

[pipefitter]

Most makers of marine topside enamels recommend that you do NOT use the plain oil based primer over epoxy saturated wood. They instead insist you use a 2 part epoxy based primer. Email Interlux about what primer to use over epoxy.They will tell you not to use their own basic oil based primer over epoxy. I tried all the products.I dont like any primers over epoxy.They all shrink and lead to the inevitable,apply,sand it off,apply.....
CPES probably knows what works with their system so take their word for it.

Of all the methods tried,the best was just using the well sanded epoxy and just the paint over that. Oil based primer is meant to homogenize a raw wood surface into something more consistent for the topcoat to adhere too saving coats of paint. It ends up just saving coats of topcoat paint. I found it wasn't worth the trouble over epoxy. The strong solvent that came with the 2 part epoxy primer ended up shrinking my fairing compound after the fact most noteable in the filled screw holes.I dont like the idea of adding yet another layer of yet a different product between paint and epoxy.

I used primer and then asked painters here on the forum who said that I could just have used the epoxy base I had to start with. They were right. It is the best looking part of the boat without a blemish.No shrinking and no adherance problems.I ended up sanding all the oil based primer off.

What the primer DID do for me upon sanding it all off was show me where I needed to do more thorough sanding/fairing. I spot primed these areas with regular epoxy and long boarded accordingly.

In regards to porkchunker's original question. Topside paint may hold up fine below the waterline on a dry sailed boat. I feel that different people have had as many varied results. I am going with the one part topside paint even below the waterline. If it holds up,all the better. If it doesn't I started at the bottom of the spectrum with what will be the easiest to sand off. Not because it adhere's less but because it doesn't seem to clog the sandpaper as readily. If it indeed holds up even semi satisfactory,it will be the easiest to renew come repaint/touchup time. I have already sanded this boat enough. The sanding/scuffing of the topside coats is minimal in comparison to the fairing. From now on,I could prep and repaint this entire boat in a couple of weekends.

[ 03-02-2006, 12:03 PM: Message edited by: pipefitter ]

[Porkchunker]

As I mentioned in the other thread about trying to find painters in the Annapolis, MD area, the boat already has one sheet of glass, some kind of high-build primer, and Imron.

If I understand what was said above, I'm better off just skipping the primer, sanding the Imron to scuff it up, and applying Imron (or another 2-part epoxy) paint.

The Imron is about 10 years old and has held up very well. The only reason I'm in the painting mode, is because I had some damage to the keel from a trailer roller that allowed water to intrude into the keel. The wooden keel was stripped of glass last summer, has dried out for about 5 months, has been sealed with epoxy, and as soon as I get a warm spell, where I can keep the garage temp above 70 F., three sheets of glass cloth will go back down on the keel.

Now...can I roll and tip Imron? If not, then I'm back to finding a painter. Or...is there a paint that is as good/better than Imron I can roll and tip?

[Porkchunker]

Found some interesting things about Imron and other LPUs:

====================
2 part polyurethane's

The two part polyurethane finishes, also known as Linear Polyurethanes have some very interesting characteristics. These characteristics are why they are so widely used in automotive applications, trucks and on airplanes. Positive points include

* Inherent UV absorption due to the the molecular structure of the linear (aliphatic) polyurethanes.
* Extremely hard finish
* High, wet look gloss
* Excellent buffing characteristics
* Recoating windows of up to 3 days without sanding (see manufacturers directions for details)

Negative points include:

* Extreme toxicity. Forced air respirator, skin and eye protection are a MUST. There are NO approved cartridge respirators - the isocyanates are odorless.
* 10-25% chance of developing chemical induced asthma which is permanent form exposure to the IsoCyanate hardeners
* Relatively high "buy in cost" Need appropriate thinners, reducers, hardeners, forced air respirator, HVLP spray gun
* Not for the casual user. These are designated as "professional use only" products. In some areas it may be hard to purchase as an amateur. Local dealer started to get worried with my questions. They are very concerned with safety and potential liability. Freely available published info is sketchy. It took a bit of digging to find the links listed. The Dupont information is in a sign-in only area of their web site.

An excellent alternative to spraying yourself, is to prep the boat and have a body shop spray on the finish.
====================

[Porkchunker]

Based on the above, Imron is 2-part LPU, not epoxy. I thought it was epoxy paint.

Will a 2-part epoxy paint adhere to Imron?

[Porkchunker]

BTT