Paint help!

[Florin {VACATIONER}]

I've noticed in his post Mike Stevenson said LPU paint is good for boats. I assume this is polyurethane paint. Is it polyurethane paint we're looking for, or urethane, or are they the same thing, or what? Is it the two part paint or just one part?Could you guys elaborate on this please? We used some urethane enamel or something like that inside.... The stuff is not too bad, but it takes forever to dry and the brush stroke are quite visible even after 3 coats plus one primer... It also scratches quite easily. We've had some kids play in the boat last year before turning it and all the benches are scratched, I assume it's from their shoes... well we'll have lots of shoes on deck when we sail and that worries me, if all paints scratch that easily the deck will probably look like hell after one sail.

Do you buy these paints at HD or any paint store, or do you order them from somewhere. It would be nice if I could find it locally 'cause we would like to paint this weekend (again). Any particular brand names and models?

I assume there is a special primer for these paints as well.. Is there more sanding involved?

Also, could someone re-post the bit about rolling and tipping please

Thanks

[capt jake]

OK.... LPU = Linear polyurethane, not the same as urethene (which is oil based). LPU is strictly a boat paint, available at boating supply houses.

I tried the Urethane (oil) and it will take over a month of warm weather for it to get hard, and no you can't hide the brush strokes with it. Latex goes on smoother than the Urethane I tried.

I feel you pain, I spent months trying the Urethane (6 coats). I sanded it all smooth (once it cured) and blew Acrylic Enamel automotive paint on it. Very quick and satisfying. I am told that teh acrylic enamel will chaulk if you leave teh boat in salt water, but I figure it will only be in for a day or two and then get rinsed.

Ray Frechette likes Brightside LPU. He seems to have had good luck with it.

Good luck in you adventure.

[Barry Pyeatt]

The LPU paints are great for boats, especially those that live in the water. They are a bit of a pain to apply, but a very short nap roller and a good brush to tip it out generally results in a really nice finish. Just don't go overboard with the brush part. You simply want to take out any bubbles and uneven spots with the tip of the brush.

The new one part polyurethane porch and deck paints are also quite good. They flow on evenly and have a very hard finish once they set up completly. Yes, that can take several days for it to reach the absolute hard stage. Some of them can be custom mixed to any color you want. Again, a short nap roller and tip it off with a good brush.

I am using a polyurethane porch and deck enamel on my hull, right from Lowe's. Mixed to the color I want and sprayed on.

The biggest advantage to polyurethanes or urethanes is that they are extremely hard wearing surfaces once they are set up.

A good example is the Flecto Brand Polyurethane advertizing from a few years back. They were rollerskating on a finished panel for days on end at home shows with little or no visible maring of any kind.

They are probably the closest thing you will find to a gelcoat type finish that you can apply.

If you can spray them they are even better, but the two part urethanes are tricky to spray. Not a job for the airless gun type painting.

But you can spray the polyurethanes with an airless if you have the right spray tip. The tips that come with the sprayers are designed for heavy bodiedd stains and latex based paints. All of the manufacturers of airless equipment have tips suitable for polyurethanes. Just pay attention to the instructions on the paint can. Some of them recommend thinning.

I think it is imortant to remember that this is a wooden boat. It will move and flex even as a rigid structure. With fiberglass/gelcoat construction, it doesn't move with the seasons. That movement and norrmal use will cause cracks in a very hard finish. That is something to consider when using automotive paints and paints designed for fiberglass boats. Wooden boats are a different breed of cat. They are still an organic product, they swell and contract with the temperature and seasonal changes. The plywood less than other parts, but even the plywood will swell enough during the freezing/thawing to cause a finish that doesn't allow for some movement to crack. Hence the checking on softwood plywoods.

There are other reasons for treating a wooden boat as just that, a wooden boat. If you are trying to make it into a fiberglass boat, it just isn't the same. And no matter how you finish it, it is still a wooden boat. So why not allow for that and get it done and in the water and enjoy it.

The Weekender in Hawaii was about as good an example of a long lasting latex pained boat as I've ever seen. Granted it was stored in a shed, but the porch and deck enamel was looking good even after dozens of years of use.

[Chris Gerkin]

I used 2 coats of Brightsides LPU sprayed on and it came out great. Like anything so much of the success is in the prep.

[JTam]

I used System 3's water reducible LPU; cleaned up with water and fast drying. Using the roller/ tipping technique and it worked to my satisfaction. The price is a bit high, I paid $32 a quart and one quart of primer and 2 1/2 quarts of topcoat. Woodenboat did a review of it not long ago and rated it a good choice.

[Florin {VACATIONER}]

Thanks guys for the quick answers.

I have spent a few agonising hours today at a few stores including our yacht shop in town (can you believe we have one here?).

I did find interlux brightside (very expensive at $45/qt) and it comes with its own primer at $35/qt. I did some calculations and discovered it would cost over $600 to paint the boat with that stuff. Not that good!

I then looked at some other marine topside paints selling at around $40/gallon and the primer the same.

The more I read up on stuff it sound like rolling and tipping won't give a great finish (it sure didn't work out great for my gelcoat) and hearing from some of you guys the same thing I am almost tempted to spray it on instead. I don't own an airless spray system but I do have access to a spray gun and compressor which is used in the automotive industry to spray cars. Would you recomend I use that for oil based enamel or urethane paints? Other than having to mask a lot of stuff, I don't really have a problem with using that. Also, when spraying oil based paints and enamels or urethanes, does one have to wait until dry, sand it and then spray the next coat, or can you just wait until tacky and get the next coat on like in car paint.... It sure would save a lot of sanding time.... Don't forget, my finished hull right now doesn't need anymore sanding; it's perfectly smooth with that gelcoat on it.

Thanks

Florin

[Barry Pyeatt]

Typically when you are using automotive type spray guns and compressors, the paint is thinned per the guidelines on from the mfg. There are so many different types of guns and pressure ratings that it would be nearly impossible to give specifics without know what you are using and having experience with it. It dries quite quickly. If you apply it too heavily it runs so several light coats are preferred to a couple heavier coats. It won't require much if any sanding between coats unless you get runs or bubbles. The quality of the finish is literally in the prep work and being consistent with the spray gun. Technique is everything according to my son-in law. (He is a top notch automotive painter in this area.) He doesn't like to spray LPU because it is hard to work with the gun and it is touchy according to him. He has sprayed boats with automotive paints and with polyurethanes. He said to follow the thinning directions and the pressure settings for the gun. And keep it clean.

[Florin {VACATIONER}]

Thanks Ray and Barry,

:-) if the answers would have been identical I would have had my mind made up already. Maan, it would be so easy if there wouldn't be so many products to chose from.

Since I have my boat finished quite nicely and I have used automotive paint before I think I'll go with the automotive paint.

I spoke to a sales rep at a paint store and he told me "no matter what anyone tells you, oil based enamels or urethanes will take up to 3 weeks to a month to fully cure". We need to turn this boat really soon, so we can't afford to wait a month to turn it...that will push our launch date in December :-(

As far as I know, acrilic enamels (car paint) will fully cure overnight.

I gotta dig out my old spray gun and get it ready for action.

Thanks

Florin

[capt jake]

oil based enamels or urethanes will take up to 3 weeks to a month to fully cure"

Ya mean I finally got one right!!??

[Barry Pyeatt]

Get back to the remodeling Jake! Times a wasting, if you are going to get that piece of Lawn art into the water this year you got to stay focused! I have some photos from Olympia Wooden Boat Fair that I will post later today.

[SeaEagle]

RE: Enamel Cure Times.

I've heard of People putting their plastic (fiberglass) boats into a motor vechicle spray painters hot room / oven in order to cure sooner (in this case it was so they could be in the water in time for an important racing regatta).

As far as a recall - they had no obvious issues with this. You would need to consider what this may do to a wooden boat.

I understand that these rooms are often set up at up to 50 degrees C or approx 122 degrees F.

From memory this wasn't too expensive (for an Elliot 5'9" racing yacht - which isn't too different sizewise from a Weekender)

If you know of a friendly spray painter / shop nearby - this may be an option for you.

[Florin {VACATIONER}]

Sea Eagle,

I don't think I would bake it like enamel.... I will be using acrylic enamel which uses hardener to cure. I can bake it in the garage at 30C. that should make it cure a bit faster. Well, faster than 15 or 20 degrees anyway.

I don't know anyone who paints cars, I can spray my own pretty good, I just bought another gun yesterday.... We'll see what kind of results we get from an HVLP. We're spraying tomorrow if it doesn't rain.

"I have a gun and I'm not afraid to use it" :-)

Cheers

Florin

[TexasPhil]

I just bought another gun yesterday.... We'll see what kind of results we get from an HVLP. We're spraying tomorrow if it doesn't rain.

I have seen the HVLP guns a few times on the web, but not sure how well they work. I am considering getting an air compressor/tank for various projects, and spray painting would be one of the considerations. Please keep us informed how well you like the HVLP vs the other spray guns you have used. Also, what are the specks on your compressor?