Polyurethane Paint Expert

[cburger]

I am coming to the end of year 3 of our sailboat re-commissioning project. A big part of this deal is repainting the vessel. I have always used Interlux products with great results and as such when I elected to paint the hull Interlux's two part linear polyurethane called "Perfection" was used. After getting quotes of almost $10,000.00 to spray the hull I elected to take on the project myself. I arrived at this decision for several reasons, first and foremost was because I knew that my prep work would be second to none. So after all the hardware was removed, every nick, ding and scratch was lovingly filled, after two coats of primer and weeks of sanding and fairing to a beautiful smooth substrate and three attempts of rolling and tipping the new very expensive paint, the job looks like s-it. So today I floated the boat for the first time in ten years and have resigned myself to spray painting the hull next spring. OK after all that the question is this, the thing I don't like about the typical marine two part paints, "Perfection", "Awlgrip" is once applied they cannot be sanded and buffed to remove imperfections that occur from painting. So some of the local so called experts have recommended that I spray a good high quality automotive paint like Imron that can have a final sanding with 600grit paper then buffed with a polishing compound to a high gloss. I would like to know if the automotive polyurethane should be compatible with the Interlux paint that is already on the boat as well as should I have any concerns with the use of an automotive paint in the marine environment. I have been told that they are all basically the same paints?

[Alan Wheeler]

Umm, where do I start. Firstly, No they are not the same. Most Automotive paints are Nitrocellulose Lacquers. They are very hard and brittle. They do not flex and most importantly, expand and contract like Polyurathanes do. So they tend to crack. I know of a Boat painter that has been caught out using car paints. They are all coming back to haunt him now. They are all cracking.
Now..who said they Perfection can not be sanded and polished. Of course it can. But ultimately, I would be looking at getting the final coats looking great without having to sand. So what exactly went wrong??
Not all polyurathanes can be hand painted. Some are specific to spraying, some specific to hand painting. The new "brushable" poly from Awlcraft is a good hand application product.
And finaly, when you do go to spray, there are some new polyurathanes on the market. They are called "recoatable" This means that you can recoat at any time in the future without having to go through the entire ordeal of preperation and undercoating. Providing the surface is smooth, it will take the recoat.
OK, this time finaly, I would seriousely look at prep work yourself, and get a yard to spray. They have the gear, the expertese and usually the good deals on paints. Honestly, if they can not spray on at minimum, 4 coats a day, they are wasting your time. It should take about a couple of hrs at most to go once right around a 45ftr's hull. The time is in prep and masking.

[David M]

I agree with Alan...the vast majority of the cost of a paint job is the prep work...and you have done all of that already. After going through all that it makes perfect sense to hire an expert to spray a marine grade LPU like Awlgrip to give that perfect finish that you went through all that prep work to get. If the yard screws up the finish coat, it is on their dime and not yours. Sags and orange peeling become their problem. If you screw up the finish coat..well then, you pay for it. I would be willing to bet that a yard that does this all the time is far more likely to get it right the first time than someone who has done it only once or twice. Ya get what you pay for.

Yards don't apply a second or third coat by waiting for the first coats to dry ...they go around the boat applying successive coats on the same day or the next day...less ideally. The idea of sanding between coats is not how it is done. Paint sticks best to paint which has not fully cured by chemically bonding.

[northerncat]

i hate to burst your bubble but at least 2 of the polyurethane paints i know can be blocked and buffed easily, jotunultra?(something) and sigma dur 400 is blockable(wet and dry) both also buff up real nice provided of course youve got enough on, before i re topcoated id have a go at blocking it back with wet and dry 800grit and see how it comes off then buff a small area and see what it looks like, as for spraying i too have never done it before but with a little care and attention and a bit of research a very good job can be achieved check mine out here
Easytalking :: View topic - sv **********
sean

sean

[SkiprJohn]

I have yet to find a person who has applied a paint with roller and brush that is satisfied with the result. I would spray myself or get a yard to do it. It just never seems to be as good as spray. However, if already on I'd try my darndest to get it smooth and glossy.
JohnL

[Islandmike]

My wife and I rolled and tipped our hull and it came out fantastic. We prepped the hull well, (lots of work), and was very careful to sand and wipe down between coats, we used interlux perfection, I know not a two part eoxy. The boat is 35 years old and basically had no gel coat left. The paint as only been on one season and it may not last as long as awlgrip, that is yet to be determined. But it is as glossy as any boat, I can make repairs and the cost was thousands, and I mean thousands less. I can now put that money down one of the many holes that Tivoli has...

[jdoe71]

Originally Posted by SkiprJohn

I have yet to find a person who has applied a paint with roller and brush that is satisfied with the result. I would spray myself or get a yard to do it. It just never seems to be as good as spray. However, if already on I'd try my darndest to get it smooth and glossy.
JohnL

Saw a Cal 2-29 this summer that the owner and his wife had rebuilt from a bare hull. They did roll and tip on the hull. The boat just sparkled, looked like it just came off the line.

[David M]

I have had Awlgrip sprayed on and I have also brushed it on and rolled it on. It is impossible to get this paint to look anywhere near as nice as when it is sprayed on

[Tnflakbait]

I use PERFECTION. I have had both good and bad results. If I were you I would try to roll and tip it one more time if you are unhappy with your previous results. It is very difficult to do well but rewarding when it works out. Yes, you can sand perfection and remove the imperfections.
I would sand the boat smooth with 250 to 400 grit. You will need to cover all of the parts that you are painting with some kind of tarp, or there is a possibility that it will go dull from moisture in the air. You need three people for the job. One person holds the tray, retrieve paint, and mix more if needed. One person applies a THIN coat of perfection very evenly with a foam epoxy roller (This roller must be replaced every 30 minutes or so because the paint will slowly eat it). The next person follows VERY CLOSE behind and LIGHTLY tips the paint out with long vertical strokes. Never ever ever go back over what you have just done. The results should be close to that of a spray job.

[SkiprJohn]

Island Mike and Tn,
You are the first folks I've heard of that have had success. Guess its all in the technique. One problem we do have here in Hawaii is a lot of humidity. I've done small hulls with a spray gun and have parts of them shiney and other parts of the same boat turn out dull. I think it was moisture inside the hull that did it.
Just got a new better compressor so will be experimenting again.
Kind Regards,
JohnL

[JohnnyC]

Yes, Imron works very nicely as a boat paint for your topsides. We have it on Callisto. The FO put it on about 10 years ago, and we are just now due to repaint. The nice thing about Imron is it can be sanded and touched up (like Awlcraft 2000). Both Imron and Awlcraft 2000 are acrylic polyurethanes. But Imron can be rolled and tipped, where as Awlcraft 2000 must be sprayed.
Awlgrip should not be buffed. As it hardens the paint stratifies, with pigments on the bottom and a clearcoat layer rising to the surface. Buffing or sanding removes the clear layer exposing the pigments. OK if you are going to paint over it with another coat, but will it will look bad if your plan is to buff out and leave as is. That is why Awlgrip is so fussy about how you maintain the paint after application (Awlwash etc).

Imron is a good choice if you plan to roll/tip off.
Awlcraft 2000 would be a good choice if you are going to spray and want to be able to buff out imperfections.
Awlgrip should be sprayed and not buffed.

Wish I could tell you about Perfection but have not used this product. Hopefully someone here can tell you if it is safe to paint over Perfection with any of these other products. In the absence of solid information you are faced with sanding back to the primer to make sure your new paint job holds up properly. Big job.

[roverhi]

I looked at a boat that was rolled and tipped using the process that Tnflakbait outlines. It came out excellent. I didn't realize it wasn't sprayed until the owner told me. Believe he used AwlGrip.

AFAIK, Imron is a linerar Polyurethane paint like AwlGrip. It apparently is not as long lasting and as shiny as AwlGrip, but a lot more forgiving. FWII, AwlGrip is the best, longest lasting paint available but cannot be touched up for small nicks, etc. Most of the other brands are touch-upable for small nicks between repaints. That can make them look better over the long term if you like to get intimate with docks like us single handers.

Aloha
Peter O.

[S/V Antares]

I have sprayed a few boats with Imron. Works fine and can be repaired. Much cheaper! Pot life (How long it lasts after mixing ) is very important on all 2part LPU paints. If you are rolling and tipping you better be fast and well prepared with extra rollers and brushes stratigicly placed along the hull. A local guy did a roll on job gulfstar 43 near Annapolis and I could not tell from a sprayed hull 15 ft away.

He did mention he had good help and still could not raise his arms for a week after!.

[GordMay]

Originally Posted by Will & Muffin

A local guy did a roll on job gulfstar 43 near Annapolis and I could not tell from a sprayed hull 15 ft away.

Which brings to mind the old paint quality scale:
There’s a 20 foot paint job, a 10 footer, and a 2 foot paint job.
An amateur paint job looks good from 20 Feet away.
A cheap paint job looks good at 10 Ft.
A professional paint job looks good from 2 feet.

[S/V Antares]

You got it Gord! In the end nothing looks so sweet as a real pro paint job. What makes me wonder is folks pay for this pimping and then have no rub rails to protect this considerable investment.
My 25 year old dull gel coat still pushes through the water just fine.