Shop our Airplanes Products Drone Products Sales
Thread Tools
Nov 03, 2002, 09:27 AM
aka: Dances with Buzzards
ICTHRMLS's Avatar
Thread OP

HVLP - Conventional vs Turbine


Hi all - just found this forum... was going to post this in OffTopic but this is probably better. Question - Whats' the difference between an HVLP (High Volumn Low Pressure) spray gun that operates on a conventional air compressor source vs. one that runs on a turbine? If they give the same results why bother with a turbine and its pricey price tag? How does a "conventional" gun acheive the HVLP function?

I already have an Ingersol-Rand 60 gallon compressor and the Porter-Cable PS-1 gravity feed sprayer looks like a bargain. Comments received at a recent trade show indicated extreme bias from those selling their respective product (turbine vs conv)

Any thoughts, ideas, comments, etc??? Thanks in advance
Sign up now
to remove ads between posts
Nov 04, 2002, 11:20 PM
York Electronics
Gary Warner's Avatar

I don't have a clue what this is about, but...


The only example I've seen that requires more pressure than my cheap touch-up gun was PVA mold release agent. They suggest 80-100 PSI and my gun is only rated for 45 PSI. Still, I've sprayed PVA at 45 PSI and it worked ok for me.
Nov 05, 2002, 10:57 AM
aka: Dances with Buzzards
ICTHRMLS's Avatar
Thread OP

Gary clueless?... say it ain't so


HVLP is short for High Volumn Low Pressure spray painting process which differs for regular spraying equipment including airbrushs. Basically you use only 10 psi but lots of cfm to atomize the material. This results in lower force, less overspray and higher rates of material transfer to the worksurface.

Turbine style HVLP rigs use...... duh - a turbine to generate the required psi & cfm air properties and can also warm the air supplied to the spray gun itself. I have found them noisy and expensive - $500.00 for a low end professional version.

Now I see an HVLP spray gun in magazines and at home centers that attaches to a standard air compressor for under $100.00 - no turbines, heavy hoses or noise. But again - if these are truly HVLP why the turbine versions and which is actually better at spraying?

As I mentioned in the original post - the turbine guys say their product is the only real HVLP. The "conventional" guys really can't say how their stuff works - just that it works. Once again... any suggestions for finding more information would be appreciated.
Nov 05, 2002, 11:54 AM
York Electronics
Gary Warner's Avatar
Ok, I see. I misread the post. I thought it was a high pressure system.

Hummm... Can't see what's the big difference since there are only two factor numbers to be concerned with - PSI and CFM. Does the turbine cause a turbulent air flow? Does it better maintain the desired PSI and CFM considering potential variables, like pickup pressure, temperature, viscosity, etc.?
Nov 05, 2002, 12:39 PM
Registered User

HVLP


I think that you can sum it up by saying that turbines for HVLP are fine if you do work in the field and do not want to lug around a conventional compressor. They are usually pretty noisey and many do not allow total shut off of the air when you no longer are actually painting. If you have a compressor then you are better off with a spray gun that is designed for it. Not all HVLP guns are really any better then the old conventional systems, but the way a gun is used is the real answer as to what you might want to buy. Having spent 40 plus years in the industry and 30 in equipment sales I can only tell you that you need a good air regulator to allow control of the atomization air and that is why HVLP actually came about. If a shop or industry had 175 PSI available, most of the time that is exactly what the painters tried to use and the overspray was extreme. HVLP guns are basically designed with internal restrictions to prevent excessive atomization. This is not the whole story, but maybe you can get the idea from this. Gud Flying........Dick
Nov 05, 2002, 03:26 PM
aka: Dances with Buzzards
ICTHRMLS's Avatar
Thread OP

Does Size Really Matter


Quote:
Originally posted by Dick
Not all HVLP guns are really any better then the old conventional systems, but the way a gun is used is the real answer as to what you might want to buy. Having spent 40 plus years in the industry and 30 in equipment sales I can only tell you that you need a good air regulator to allow control of the atomization air and that is why HVLP actually came about.
Thanks for the info - is there a recommended minimum airhose size for a standard compressor to an HVLP sprayer or is it a matter of the regulator not causing a pressure drop? The sprayer I refered to has a mini-regulator built in at the body of the gun so I should be able to use a higher pressure at the main reg on the comp, right?
Nov 05, 2002, 06:30 PM
Registered User
HVLP on conventional compressor -

My dear old dad has one of these guns. Basically there is a sizeable air-chamber that de-compresses the high pressure from the compresser.

This is then regulated within the gun to some pressure (prob. 10-15psi) and of course whatever volume is available. Recommended pressure for the gun to work is 90+ psi at some ~20 cfm.

It works well, and it is damned impressive comparing the output to a standard HPLV sprayer. It is really good at getting a nice "flashed" finish.

Think that covers it.
Nov 05, 2002, 08:16 PM
Registered User

HVLP


In most cases the HVLP guns do need volume as opposed to pressure. Some shops were/are using cheap service station hose. The OD (outside diameter) looks the same but the ID (inside diameter) is quite small and restricts the air volume. Today almost all the HVLP guns will work quite well if a non restrictive regulator and a reasonably short hose of 5/16 inch ID is used. The cheaper hose is usually 1/4 inch ID. So called service station hose is normally 1/4 inch ID so that cars can run over it without destroying it. I don't know of any gun that has a "true regulator" built in. There are some restrictive valves, often refered to as "cheater valves" but they are only good when the trigger is fully opened and they reduce volume quite a bit. I use them to test the spray guns I rebuild, but I would never use them to paint a car with. For our use in models it does not present a problem as the total amount of material we use is very minute. Gud Flying......Dick


Quick Reply
Message:

Thread Tools