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cburger · 29-07-2020, 13:19

I have decided to spray my sailboat myself, the paint will be Alexseal LPU.

Wondering if anyone knows of small portable equipment that will meet the paint manufacturers requirements of pressure for correct atomization?

Vessel will be painted outside and would like to place gear next to boat. Electric will 115v AC.

Bill O · 29-07-2020, 14:10

Are you doing this in a marina and they're ok w/you spraying?

Most marinas do not allow outside people to spray any more.

So please tell us what the specs are for this particular paint?

Have sprayed several boats w/cheap HVLP guns from HF with Awlgrip and several Interlux products, no problem. I prefer the gravity vs. siphon cup gun. Pre-covid they were ~$10 ea. when on sale.

Would get a decent sized compressor w/~20 gal. tank to reduce pulsing and an inline water separator.

Try some test sprays to get the pattern, amount of paint and gun pressure dialed in before starting to paint your boat.

cburger · 29-07-2020, 14:33

sold my HVLP sprayer, will noy come close to Alexseal pressure requirements foe their paint.

Chotu · 29-07-2020, 14:45

Recalling my research when spraying my catamaran:

There is NO cheap, portable spray setup that will work well.

You need a huge, high CFM air compressor probably running on 3 phase power and an air drying system for keeping water/oil out of the spray.

After you get your air source sorted out, you can do a couple different things. I ran a standard pro gun loaned to me by the paint salesman. Non HVLP. I used that with a pressure pot and achieved flawless results my first time ever spraying paint.

If you want easy/cheap, just roll and tip it and accept the slightly less perfect result. It’s really not too big a deal. The difference is negligible between spraying and roll and tip. You can’t see the difference unless you’re looking for it and within an arm’s length of the boat.

guyrj33 · 30-07-2020, 09:36

your typical 120v 20 gallon compressor with water separator will be fine for spray painting. Do try to get a good spray gun.
Wear a respirator.

zstine · 30-07-2020, 09:41

The compressor will be the biggest $$ part of the system. Maybe see if you can borrow one. I use a 20gallon compressor SCFM 6.1 @ 40psi (which is close to spray pressure), craftsman $300. I have both HVLP, siphon / pressure cup guns. They are cheap from big box stores like Lowes. The HVLP is for very thin paint while the siphon/pressure cup combo will handle much thicker paint. The difficulty is keeping them clean and after awhile buildup causes them to degrade and need to be disposed of. Perhaps an expensive gun would be easier to clean and last longer. I have no experience with Alexseal LPU and can't say if it is thin enough for HVLP... probably is.

That said, you will get nearly the same result, maybe better, with a roll n tip method and it will be much faster since you won't need to protect everything from overspray. Spraying is an art and takes practice to get good results. I strongly recommend a paint that is roll and tip capable and using that method if you don't have experience spraying. Roll n tip is also less picky about wind, so since you said you are doing this outside... well, if spraying outside, you may want to tarp/tent the boat

George_SD · 30-07-2020, 09:43

Won't a typical airless sprayer work better for a job like that?
https://www.harborfreight.com/painti...kit-60600.html

Buy, use, sell for half the price. Or buy a used one on CL.

Pauls · 30-07-2020, 10:31

A few practical points which will help you with your job:
1. You apparently have a spraying pressure spec from the paint manufacturer. Your compressor needs to be big enough to maintain that pressure with the sprayer you use. This is typically not that big. As a guess (you give no specifics) a 5 hp, 110 VAC compressor will do fine.
2. A decent size (not a tiny) water separator is MANDAATORY. Water droplets in the paint will ruin the job.
3. Do your painting in the very early morning. Have all sanding prep done the day before. Start early, wipe off all dew, tac rag the surface, and paint. The reason for this is that any dust in the air that lands on the paint before it hardens will degrade the job. Most dust is caused by human activity and wind. Get the spraying done before people are up and about. This is actually a pretty big deal.
4. You will want to lay on a heavy enough coat for it to flow out and produce a smooth surface. But not heavy enough to run. A very effective technique is to make a first very light pass which merely dusts the surface. This light dusting is followed by your regular coat. The dusting creates a textured surface which allows a heavier coat of paint to be applied without running.
5. You can probably rent an air compressor. Get a HF gun which matches your paint requirements. Practice on a test panel first. Use that to verify/develop your pressure settings/thinning/painting technique. When that's down then do the boat.

Good luck. With attention to detail you can produce a very good job.

alansmith · 30-07-2020, 10:49

Tip and roll produces a very nice yacht Finnish. It is quite easy to produce it. Cheap. Repeatable. It is not difficult work.

Briarpatch · 30-07-2020, 12:22

I just painted my boat with Perfection, using the rolling method. I think it came out great. Used 1/8in foam rollers. Used once and then tossed it.

It sure beats having to do the clean up of a spray system like I did the first time I painted to boat. Used so much less clean up supplies as well (saved $).

cburger · 30-07-2020, 13:08

I have painted this boat in the past using roll and tip and sprayed shear stripe with HVLP. At the time the hull had all fittings removed so could maintain a continuous wet edge, paint thinned to maximum allowed, used 3'' foam hot dog rollers, no tipping of paint. The job turned out so well most people thought it was shot. Now that the boat has been put back together there are just to many fittings to paint around that it is doubtful that I can duplicate the result.

Most marine LPUs want a much higher pressure than HVLP can deliver in order to get proper paint atomization. The shear stripe spray work was good, but could of been better.

The nice feature with Alexseals paint is it can be sanded and buffed. Directions call for 4 hot coats I am a believer in following the manufacturers guidelines to the letter.

So quality gun Devillbliss or Binks, correct delivery pressures and nozzle size, gun tuned for proper pattern and coverage before use.

So I thanks to all for their insights here.

Fore and Aft · 30-07-2020, 13:47

All I can say is I hope you have sprayed before Cburger? I have seen some awful spray paint work, dry areas, runs and over spray all over deck fittings. Just a few weeks ago I surveyed a house boat that had so many runs on the topsides that I reckon it devalued the boat. That same week I surveyed a power boat that where the guy had not bothered to properly mask the stainless steel handrails and they looked like they had white measles.
You will also need a smart offsider to hold your spray hose and keep you on your toes when you are spray painting. I have painted plenty of boats and don't under estimate someone watching to make sure you are getting good coverage and not bumping into any fresh paint.
Cheers