Dumb question about HVLP conversion gun

[Larry Browning]

I just got the HF HVLP gavity feed spray gun. There is a knob on the side of this thing that the manual says is the regulator (I think that is what is says) but it doesn't tell me what it does. I have never had a single lesson as to the use of any kind of spray gun, HVLP or otherwise. So do not assume I will know what you are talking about terminolgy wise. I was hoping the manual would help me with how to use this thing. I have had pretty good luck with it so far and really enjoy using it, but I'd bet that turning some of these knobs might help me get better use of this gun. Is there a book or some web site that might help me better understand how to use it?

Thanks,

Larry

[Chris Padilla]

Larry,

I don't have a gravity feed HVLP gun but I do have an Apollo 1000 HVLP Turbine powered gun. Basically, there are two adjustments on the gun:

(1) Pattern of spray: circular, vertical and horizontal ellipse
(2) Amount of spray: limited by how much the trigger is pulled; mine has a screws that adjusts how much the trigger can be pulled.

Other adjustments are the size of the tip and needle that fits in the tip. Different opening are needed for different viscosities of liquids. The more runny/watery the liquid, the smaller the tip/needle...the heavier (latex paint), the larger the tip/needle.

Keep in mind these adjustments exist on my gun...dunno if yours is much different.

[Waymon Campbell]

Larry,

I don't have a gravity feed HVLP gun but I do have an Apollo 1000 HVLP Turbine powered gun. Basically, there are two adjustments on the gun:

(1) Pattern of spray: circular, vertical and horizontal ellipse
(2) Amount of spray: limited by how much the trigger is pulled; mine has a screws that adjusts how much the trigger can be pulled.

Other adjustments are the size of the tip and needle that fits in the tip. Different opening are needed for different viscosities of liquids. The more runny/watery the liquid, the smaller the tip/needle...the heavier (latex paint), the larger the tip/needle.

Keep in mind these adjustments exist on my gun...dunno if yours is much different.

Larry - I have the Wagner HVLP gun. Sounds like you are describing the air regulator adjustment, which allows you to adjust how much air gets to the gun (handy to prevent a lot of over spray). On mine I have it adjusted at about 10PSI when spraying lacquer. Your mileage will vary. A good book on finishing is Taunton's "Complete Illustrated Guide to Finishing" by Jeff Jewitt. Jeff explains in detail the various adjustments for HVLP guns, as well as his strategy for getting the most from the gun. A definite must read.

Good luck...

[Larry Browning]

Waymon,
This is not the pressure regulator gauge. This is a knob on the side of the gun itself. I have messed with it and it seems to change the amount of paint that is sprayed, but I really have no idea what it does. There is a fluid control knob that seems to control how far the trigger can be pulled back (the manual says it adjusts the spray width) and an air adjusting valve at the bottom of the handle that the manual says adjusts the air-to-material mixture (what the H-E-double hockey sticks does that mean?) Sorry to sound so clueless, but that's what I am on this thing.

[Dennis Peacock]

Hey Larry....

Let me help you out here a bit.....

On most of the HVLP conversion guns...there is a knog on the SIDE of the gun and this is more of what Chris was referring to. It is the air regulator that does NOT regulate the air pressure to the gun but to the TIP and controls the overall spray pattern that is being sprayed. Completely OFF and the gun will spray a very tight circle pattern and wide open and it will spray a wide FAN pattern. You loosen and twist the spray cap to adjust from verticle to horizontal.

The knob on the BACK of the gun, top side is the fluid control knob. For lacquer and shellac, about 1-1/2 turns OUT from fully closed is just about perfect for those top coats. You'll have to experiment a little there.

If your gun has a knob on the BOTTOM of the handle part....this part is supposed to control the volume of air going to the nozzle. You DO need a more accurate pressure regualtor for your HVLP conversion gun so you can accurately adjust the actual pressure going into the gun. Somewhere between 10 and 20 PSI is good. They make a small regulator that attaches to the bottom of the gun so you can adjust air pressure AT the gun and while spraying until you get it regulated to suit you spraying method and material. Most of these little regulators come with a face that has a GREEN zone which is best suited for HVLP conversion gun use. I run mine in the top end of the green zone. I have the Porter-Cable HVLP conversion gun and is gravity fed that I got from the local BB store. Great little gun.!!!!

I hope I didn't confuse you any and I hope this helps clear up your question.

[Larry Browning]

Dennis,
Thank you for an explanation I actually understood! So the knob on the back should be adjusted based on the viscosity? The thicker the paint, the further it should be opened? Also, the air adjusting valve is a part of the gun, not the pressure regulator, this is a small knob sticking down from the bottom of the handle. The pressure regulator is attached to the air port and the npt connector is attached to the regulator. I have looked to the PC unit and it seems to have the same set of controls. When should this knob be adjusted? Knowing what it controls helps some, but when to adjust it and in which direction I think would help me more.

What I don't understand is the relationship between say viscosity and which way I should adjust these knobs. For instance should I increase or decreace the pressure as the paint gets thicker? If I want to reduce overspray what should I do? (or can that be adjusted?)
This discussion is really helping me, dispite my thick skull. I must get to work at my day job, but I have a few more questions I will post tonight.

Larry

[Chris Padilla]

Larry,

On my gun, the pressure is regulated by my 2-stage turbine (factory set, I guess you could say). I am not hooked up to a separate compressor.

I am not sure how your gun deals with different viscosities of liquids. On my gun, I change the tips/needles. I have a little kit with 5 different tips...all of various diameters of openings. Along with those 5 tips are 5 long needle-like pieces of metal that fit perfectly in its mating tip. I use small opening tips/needles (like 0.75 mm) for very liquidy stuff like lacquer or poly and I use my largest opening tip/needle (2.5 mm I think) for spraying latex--even then I normally need to thin the latex with Floetrol (don't use water to thin latex).

[Ken Combs]

Take a look at this link.. Way more info than you need but these guys are really spray painting experts.http://www.autobodystore.com/ms6.htm

[Ken Combs]

]Take a look at this link.. Way more info than you need but these guys are really spray painting experts.http://www.autobodystore.com/ms6.htm