HVLP Spray Gun

[Chris Duncan]

Sort of new to this HVLP spray gun. Works fine when first used but after a re-load it spatters. Seems like the paint dries a little in the nozzle piece because it takes a while before it clears up and sprays right.

What is the normal procedure? Do you flush the thing with reducer right before a reload?

Is it correct when the paint calls for 10 psi air pressure that that is the dynamic pressure and not the static pressure? In other words for it to be at 10psi while the trigger is pulled it has to be at 18psi when the trigger is off.

 

[Mesa]

It is rated at dynamic pressure at the gun handle. If you are spraying a high quality paint properly reduced the nozzle should not clog. Get and read the paint manufacturers recomendations for mix ratios and gun tip size. HVLP is not much different than a conventional gun except it does not atomize as well, therefore it is harder to get the paint to lay down as slick. Is it a quality gun? Typically you would be using 25-35 pounds dynamic with todays equipment.

 

[Chris Duncan]

Is it a quality gun? Typically you would be using 25-35 pounds dynamic with todays equipment.

Yes, quality, $150, started with a home depot for $80 and had to step up. It shoots fine after it's freshly cleaned.

The paint calls for 10 psi, the spray tip has 10 psi max stamped right on it, but in the written instruction it says about 40 to 60, but I think that's before the small regulator at the inlet.

It also says "this is an HVLP gun, be sure to read pressure requirement carefully" but then it says nothing else about pressure.

The tip size is 1.7m which is on the high side of what the paint calls for.

 

[Mark Worthington]

Many will argue that "quality" spray guns start at around $300.

 

[Chris Duncan]

It's just for primer, having a pro do the color coat

 

[Mark Worthington]

Gotcha. My Devilbiss Finish line will be fine for primer too, but I'm shopping for a Devilbill GTI, Sata or Iwata for color and clear.

 

[Mesa]

I am not too familiar with the anything but a 'gravity feed' (cup is on top of gun and more effecent) type equipment. Although earlier in my coatings career I used conventional 'suction feed'. I find it difficult to swallow that a primer would be in the 1.7 mm tip range, more typically you'd be using a 2.0 - 2.3 for a heavy bodied primer. If the tip is too small compaired to the body of the primer it definitley will tend to clog very easily. Maybe you are only shooting a light sealer/primer which would explain the small tip recomendation.

As mentioned a Devilbiss 'Finishline' is a great gravity feed primer gun, with the right tip and air cap they may even do a decent job of top coat application. I think they are targeted in 150 dollar range.

Could you post a picture of the gun? This ten pound recommendation has really got me curious.

Thanks .... hope I have been of some help.

 

[CliffBeer]

Possible to buy use a non-HVLP gun? In other words, are good quality non-HVLP guns easier or better to use than an HVLP? I haven't painted for a number of years and back then I was using a non-HVLP gun and the results were really very good. I now have a good quality HVLP gun and have not had much luck with it - have changed tips and experimented with pressures but results have been only modest. Any advice on this point?

 

[Dave]

Talking about HVLP guns
I have found that some colours spray much easier than others.:shrug:
I have sprayed white and light blues with really good results, but
when I sprayed a dark red I got a really bad orange peel finish.
I asked the PPG paint Rep at work and he said that some colours are heavier than others but has never heard anything like that from the Pro's.

 

[Mike Dozier]

Kalun

As mentioned...you might try a larger tip size.
Other tips include increasing the pressure (10 psi be damned),
and adding more thinner. My HVLP "splattered" too until I boosted
the pressure a bit and added some thinner. Then went on nice.
Also suggest experimenting with a test panel before shooting the car.
Once you get the hang of it, it really is a nice system.
But you can sure put down a lot of paint in a hurry if you're not careful.

MikeD

 

[Mesa]

At the time of introduction to HVLP, the challenge for HVLP was atomization (breaking up paint into small particles) vs a convetional gun. Hence, old guns worked better than HVLP but, now-a-days the difference is virtually nill if using a HIGH END GRAVITY FEED HVLP. I do not know of anyone using suction feed HVLP in any of the pro shops our business is connected with. If priming a Finishline is a good choice, if finish coat is the goal a Sata or equivalent a good choice.

On the red heavy texture - sounds odd, but not unheard of........ Sure there was not a chemical mix up? As in using a base coat (requires a clear coat) reducer in a single stage red (or the reverse)? I've done this one myself, sure makes the spray quality uh, ......different.

Is the 10 psi thing on a suction feed gun? (again I have no experience with a suction feed HVLP as I don't see them in shops)

Maybe some one could post a picture?

 

[Jim S.]

I'm not a finishing expert, but I've done alittle more than a half dozen overall paint jobs. Last year I was looking for a new gun and seriously considering a HVLP, but I'm used to a conventional gun. Just before placing an order for a SATA HVLP I stumbled onto information about SATA's new RP gun. RP being reduced pressure, Not HVLP. They designed this gun due to complaints about HVLP guns from experienced conventional gun painters.
They said this gun sprays like a conventional, good "atomozation", but uses little pressure to due so (30 PSI) These guns meet new environmental standards and have very good transfer rates. Since I had experience with conventional guns I decided to buy there SATA RP gun. This gun sprays awesome just like they claim at very low pressures and good transfer rate.

I sprayed the under side of a car at 20psi with good success, very low over spray and fog in the air. I sprayed the top of the car at the recommended 30psi.
It sprayed awesome. The paint laid down great, no really orange peel. I used just over 1 Gal of paint for both the top and bottom of the car, which included door jams and all. This was a color change job so everything was sprayed including the engine bay. I used to buy 6 quarts just to do the top of a car, so this was amazing.

I would highly recommend considering this gun. I purchased the one with the digital pressure gauge built into the handle of the gun. Very cool feature.

Just wanted to share this with you guys.

 

[Steve Briscoe]

SATA's new RP gun. RP being reduced pressure, Not HVLP. They designed this gun due to complaints about HVLP guns from experienced conventional gun painters.
quote]

Jim -
Good review. Which of the guns listed on satagun.com did you buy? They have several RP guns.

Thanks,
Steve

 

Jim, thanks for the tip! Which sata RP gun did you buy?

 

[Jim S.]

I bought the SATAjet RP

Here's the link: SATA.com - SATAjet® RP™

I purchased it with the digital readout as I mentioned above.

 

[Chris Duncan]

It's a Taiwan unit, a definite step up from the China one from Home Depot, at $150 it's just what I need, this is my LAST project (supposedly!!)

LINK

The primer filler is some cutting edge stuff, it just came out, the tip recommendation with the primer is 1.4-1.8. The gun is 1.7 so in the ballpark.

It's HVLP gravity feed. Wanted to save product and pollute less. I've only sprayed with conventional guns before, like you guys are saying this thing is more finicky. I upped the pressure just a little and added some reducer.

It's very sensitive to drying in the tip. I'm shooting some reducer through it between loads and it seems to work better that way. All the settings have to be right also, the volume one especially.

This primer is really nice, expensive but nice. It's isocyanate free and it sands a lot easier than the catalyst primers I've used before. So nice to see this thing all one color. Think I'm going to drive it around for awhile to make sure no fglass cracks and there's no compatibility issues with the fillers primers etc. Had a bad experience one time with some spot putty, it blistered 3mo after the final color coat.

The only thing I don't like about the primer is it's not recommended over bare fiberglass, adhesion issues. Had to use some expensive spray can stuff on the bare spots.

PRIMER