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View Full Version : Gravity vs Pressure pot HVLP guns...



Scott Larson
01-03-2006, 7:29 PM
Here is another “what’s the best gun” questions from someone who is spraying the infamous thick paint (in this case S-W proclassic acrylic) and has gotten fed up with the popular Harbor Freight PSH1 clone (with 2.2mm tip).
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I'm wondering if anyone who has used both pressurized and gravity fed HVLP guns can comment on the benefits / cons of one system over another. Particularly when comparing guns from a similar price point (i.e., your money goes farther with a gravity feed gun over a pressure pot since there is less additional equipment needed).
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Here are my specifics…
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I’ve been “ordered” by the LOML to paint a large kitchen’s worth of solid oak raised panel doors/cabinets. I rolled/dry brushed the cabinet faces/sides and have sprayed some of the doors (after using significant amounts of filler to kill the grain on the panels as the wife doesn’t like “the look”). The completed doors actually look pretty good but that is only because the proclassic seems to level very nicely (thinned with water and XIM latex flow additive at the recommendation of my paint dealer). I’m painting 5-6 doors at a time and all doors are sanded, primed, and painted horizontally (out side when weather permits).
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The biggest problem I seem to currently have is that the Harbor Freight gun has difficulty delivering a nicely atomized coat. Instead, it kind of spits and splats but again, if the coat is wet enough, the paint will eventually flow and level. Further, I notice a pressure drop while spraying (it will spray quite powerfully for the first few seconds and then it will decrease in pressure) so it's difficult to get a nice even, wet coat. It may be my compressor (rated at 8.8SCFM @ 40 psi) is not able to handle enough CFM for this gun?
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Like many on the board, my intention in the future is to use more traditional finishes as opposed to paint so I’m curious if it’s better to “bear through this” with the idea of having a better gun for lighter material in the future (although I recognize that much of the expense comes in replacement tips).
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My current price point is $300 or less. So, does anyone have any input if a midrange gravity gun such as the Walcom Slim S (available for around $250) or a Astruo BBS (around $260 with larger tip) will handle the heavy paint as well (or nearly as well) as a “less expensive pressure pot gun” such as the infamous Wagner HVLP (around $200 with the additional bigger tip) or the QualSpray 350 available at Homestead Finishing? Should I expect that any of the quality gravity guns will work better for me than the Harbor Freight or, all else being equal, do I just need better thinning technique?

Finally, how bad are the pressure pot guns to clean?

Thanks for any an all help.

-Scott Larson

Phil Phelps
01-03-2006, 7:59 PM
Scott, you can call me, 214-565-1337 shop hours CDT, but it's simply too much to say in this space. If you have access to "real paint store" and, if it sells spray equipment, I'd beat a path over there and tell 'em what you want and what you're doing.

Duane Pulliam
01-09-2006, 2:29 PM
Scott:

If you are getting spitting and spattering, your gun maybe getting clogged. Are you filtering your paint before/while filling the cup? If sounds like your compressor is big enough to keep up with the gun unless you are spraying rather constantly and in large doses. How much are you thinning the paint? I have sprayed Proclassic with a PSH1 w/1.5mm tip and it does a good job if the paint is thin enough. Pressure pot guns will allow spraying higher viscosity materials with a smaller tip by upping the pressure, but if the material is thinned appropriately, a non-pressure gun will do just as good. Hopes this is some help for you. Good luck.

tod evans
01-09-2006, 3:07 PM
Scott, you can call me, 214-565-1337 shop hours CDT, but it's simply too much to say in this space. If you have access to "real paint store" and, if it sells spray equipment, I'd beat a path over there and tell 'em what you want and what you're doing.

scott, phil offers good advice........tod