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-   -   High Quality Portable Spray Equipment For Marine LPU Paints (https://www.cruisersforum.com/forums/f55/high-quality-portable-spray-equipment-for-marine-lpu-paints-237720.html)

cburger 29-07-2020 13:19

High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
sold my HVLP sprayer, will noy come close to Alexseal pressure requirements foe their paint.

Chotu 29-07-2020 14:45

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
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

cburger 30-07-2020 13:51

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Alexseal specs a 42 to 70 psi and a 1.0 to a 1.4 mm nozzle

Fore and Aft 30-07-2020 13:56

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Cburger the only problem with 70 psi is the over spray is terrible. You better cover everything in the boat yard.
Cheers

cburger 31-07-2020 12:55

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Quote:

Originally Posted by Fore and Aft (Post 3197898)
Cburger the only problem with 70 psi is the over spray is terrible. You better cover everything in the boat yard.
Cheers

Boat will be shrink wrapped to prevent over spray,

Scubaseas 31-07-2020 15:17

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
The pressures listed and tack times look pretty steep. I'll toss in my $.02 from having painted cars/owned a repair and body shop for 38 years. There are two ways you can spray. One would be an air compressor and either a HVLP gun or a regular gun. The tip size specified is a bit bigger than what you would find for automotive paints but can be had. Guns are pretty cheap- a good one plus tip abut $250. The compressor at that pressure is going to have to be pretty substantial. My personal preference if a gravity feed HVLP gun and a large compressor with a large, effective dryer system. A pressurized paint pot would be nice for a job this big but your tack time would easily allow you to not use one. Get an extra cup and have a helper stir/pour/swap cups on the spray gun.

HVLP guns put more paint on the surface but needs a bigger compressor.

The other way is with a turbine which is a self contained HVLP electric unit. A decent unit big enough (like a FUJI) could go $800 or more with the right needle and tip. Note some people are not fond of these as the hose gets heavy on big jobs even if you toss it over your shoulder. Plus side is they are much better with water not getting in the air supply.

You might benefit from some reading here: https://pittsburghsprayequip.com/blo...spray-gun-faqs

To get a good finish you need the right tip, the right reduction (viscosity), the right pressure and the right technique. You would definitely benefit from experimenting and practice. Maybe do the prep work and hire a pro to shoot it for you?

Bill O 31-07-2020 15:56

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Quote:

Originally Posted by cburger (Post 3197017)
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.


After all the comments re: the Alexseal, are you sure you want to do your first spray job w/this paint. While it is the "newer" Awlgrip, the amount of solids in it poses more challenges and high end spray equipment than other paints.
I haven't used Alexseal, but have sprayed several boats w/various Interlux products and Awlgrip. Will say the Interlux products were the easiest to use w/good results, while the Awlgrip was more complex w/different accelerators/solvents depending on the conditions created a bit more a learning curve for the Awlgrip for good results.
The boat I painted w/Interlux in 1992, we sold in 2016 and the hull still looked very good.

If I had to compare bang for the buck, would recommend spraying w/Perfection (Interlux) over the very expensive Awlgrip. If you follow directions and do the prep work well, you will have a very good long lasting paint job w/out breaking the bank.

Scubaseas 31-07-2020 16:32

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Quote:

After all the comments re: the Alexseal, are you sure you want to do your first spray job w/this paint. While it is the "newer" Awlgrip, the amount of solids in it poses more challenges and high end spray equipment than other paints.

^This. If you are going with cheaper spray system it may not easily handle this paint. The 42 to 70psi spray pressure is quite a bit higher than other paints.

Fore and Aft 31-07-2020 22:39

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Cburger you will need an extraction fan if you are spraying in a tent. I was once involved with a job where the extraction fan deposited paint on a number of parked vehicles. It was a fairly costly mistake.
Cheers

jpendoley 03-08-2020 06:02

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
I rolled and tipped my old Pearson Vanguard with Perfection-Flag Blue-very demanding color. It was close to flawless. Many unsolicited positive reviews. Very easy paint to work with. It is not that durable a finish though-I only got five years out of it before I recoated-but that was an easy one day job.
I have not heard anyone mention it so I will- I thought Interlux Perfection was a two part urethane-thus very dangerous to spray without supplied air for the human-not the paint. Something to consider if you thought of spraying.

scfoster 28-08-2020 06:57

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Going to use Alexseal as well (arrived yesterday). Have done a LOT of research on it, including calls to the SC headquarters.

You will NOT get much better results spraying that using a roll method. It will use a LOT more paint and has all the other hassles noted already in this thread.
Have a FaceTime appointment tomorrow with Andy from BoatWorksToday (check out his YouTube channel), just to go over things one last time.

Alexseal just came out with A5018 Topcoat roll additive. It is supposed to provide near spray parity with a LOT less work. At $24, it's going to save a lot of money (overspray) and time.

Have 3 hatch covers in the garage, one of which needs new core/fiberglass work. Going to do some sanding and see if I can get painting done this weekend. I'll post results.

Almost forgot to mention. If anyone goes the roll method, there are different products that need to be used with the primer and topcoat. They are spray or brush specific. Make sure your supplier knows which you need...ask me how I know.

Thumbs Up 28-08-2020 11:57

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
My experience with Alexseal is that the fumes are even more toxic than Awlgrip. Mask up!

scfoster 28-08-2020 12:04

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Quote:

Originally Posted by Thumbs Up (Post 3219188)
My experience with Alexseal is that the fumes are even more toxic than Awlgrip. Mask up!

Absolutely! The 20' wide garage door is open with a large fan going, in addition to the 3M respirator.

randomrun 28-08-2020 13:41

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
When rolling Alexseal, follow up with a dry roller to remove any bubbles. Worked great for me.

scfoster 28-08-2020 13:58

Re: High Quality Portable Spray Equipment For Marine LPU Paints
 
Quote:

Originally Posted by randomrun (Post 3219271)
When rolling Alexseal, follow up with a dry roller to remove any bubbles. Worked great for me.

Just got off the phone with Alexseal. Using the roll additive, there is NO tipping and backroll lightly with the unloaded wet roller you're using to add paint. No dry roller.

Over the Alexseal primer, add 1st topcoat, wait 2 hours and add second coat. Wait a couple days, 400 grit sand then add 3rd (final) coat. Can be applied down to 50degF.

They are good about answering the phone and taking questions.

Training Wheels 28-08-2020 15:07

High Quality Portable Spray Equipment For Marine LPU Paints
 
Russel Brown has a good pamphlet on rolling paint to get a spray quality finish. I think his website is PT watercraft.


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