HVLP Compressors & Guns

[Mike Guilbault]

I've been rolling fairly successfully for over a year now, but would like to get more consistent results.  I find with with darker images, if the conditions are not just right, I still can get some rolling lines/marks.  So I'm considering switching to HVLP.  BC's site has a video for a $125 spray booth using the http://www.wagnerspraytech.com/portal/control_spray_plus_en_spray,363634,358970.html system. Any thoughts on this system, or what are the other options. I'm not high volume, maybe a dozen canvases a month, but would like to get the right gear - not necessarily the cheapest - or more expensive either. Threads I've explored are a few years old so looking at what's available now.

[felix5616]

Get a Fuji HVLP system, very high quality item, perfect spray delivery.

[darlingm]

I've been very happy with Harbor Freight's $15-20 HVLP spray gun, actually.  In older posts I saw a few others recommend it, tried it, and was surprised.  I do have to run a higher PSI through it than the gun's max to get a spray I like, but it's never exploded or anything.   

I wound up dedicating a bedroom to it.  I stapled painters plastic tarps to the walls, and put 4x8' sheets of insulating foam up to pin canvas to.  Explained to my wife someday we'll need to sand the walls & repaint, and replace the carpet.

[Geraldo Garcia]

I tested/used several cheap HVLP turbine painters and the best between the cheap ones, in my opinion, is this one: http://www.blackanddecker.com/power-tools/BDPH400.aspx
Low noise, good spray, not so much overspray, very long hose (so you don't need to carry the turbine on your other hand while spraying large canvases) and incredibly consistent. After a month of use I am very well impressed.

Sure the Fujispray is the best, but this little fellow does not disappoint and is quite inexpensive.

[John Nollendorfs]

Mike:
If you already have a compressor that will deliver 3.5-4 CFM at 40psi, just try one of the cheap Harbor Freight guns. I started off using a $70 B&D Twin Turbine, but the Harbor Freight gun delivers a much nicer result.

Just remember Spraying is a bit of an art, so you have to practice to get it right.

[Roscolo]

 +1 for the Harbor Freight gun.

[Larry Heath]

The thing you need to remember is that you are spraying a fairly viscous material and depending on what type of material you intend to shoot (I shoot BC timeless straight) it may not even be diluted. You need a gun with a tip orifice size of at least 2.0 mm; I shoot with a Vaper Mod #19123 which has a 2.3 mm orifice and 1 liter aluminum cup. It’s a cheaper commercial brand that works just fine in this application and runs about $65.

The thing is that I can shoot between 8” and 12” from the canvas and cover about 8” to 10” a pass. The smaller the tip the closer you’re going to end up needing to be to the canvas to get a nice even coverage, as close as 3” or 4” with a small tip, makes it a bit harder to get a good overlap and even coating.  Plus the smaller tips generate a finer droplet size and more overspray.  I can put a nice uniform wet coat on a 44”x44” canvas in under 30 seconds, no runs or drips, and a second coat in 10 or 15 minutes and I am done. It takes way more time to get ready to spray than the actual spraying itself.

I use a Kobalt 1.8-HP 20-Gallon 150-PSI Electric Air Compressor which is right at $200 from Lowes, unbox it plug it in and it’s ready to work. Thing is this is an oil less unit. Don’t use a compressor that has an oil lubed pump, you will have problems if you don’t use significant filtration. This might seem over kill but more problems in spraying can be traced to changes in pressure and volume from too small pumps than you can shake a stick at. For these types of guns you need about 5 scfm of flow at 40 psi, which is exactly what this unit is capable of.

So the three big tips, get a gun with a 2.0mm or larger tip, get an oil less compressor and it needs to put out at minimum 5 scfm at 40 psi minimum.

Later Larry

[Keithw1975]

I recently sprayed 60 3'x7' prints for a trade show using the Kobalt HVLP gun. It only has a 1.5 tip, if memory serves me, and it seems to do a pretty decent job, though I think a larger tip, may make it faster. We also have a Kobalt 60 gallon compressor that is an oil type. Never had any issues with oil contamination, and it has no problem keeping up with me spraying continuously.

[Mike Guilbault]

So... are some of these compressors not HVLP?  I have a Makita MAC2400 that I use for my canvas stapler but didn't think it was suitable for spraying.

[Keithw1975]

The gun is whats HVLP, not the compressor. Generally you need a compressor that can pump out around 6CFM or more. You can get by with something smaller if it has a big tank, but once the tank runs out you will be sitting around waiting for it to recover. If your not doing too much volume though, anything can get you by.

[Mike Guilbault]

I probably do 1 or 2 canvases per week (20x30 or 24x30s mostly).  The MAC2400 is rated 4.8 SCFM @ 40 PSIG or 4.2 SCFM @ 90 PSIG.  Not exactly sure what that means.  The tank is 4.2 Gallons.

[Keithw1975]

That rating is a little low, but you could certainly get by for a while. Smooth movements when coating will take time, and practice.

[Larry Heath]

I think that the reason for not having an issue with the oil lubed pump might be that pump doesn’t run long enough to generate enough heat in the lube to volatilize it where it gets passed the rings and into the tank and onto the work.

Then too, oil may not be nearly the problem in shooting the types of coatings we are talking about here, as opposed to the automotive finishes that I learned on. I assumed oil would have a similar effect, maybe not? Still all in all if I had my druthers, and, I was buying a new pump I think I’d get an oil less pump just the same.

At the level of use it seems you will be doing Mike, I’d guess that the Makita should work just fine, it may run most of the time you are spraying do to the small tank capacity, but the pump on its own seems like it should keep up with demand. If you had to do a lot of work very quickly, things might be different, once the pump gets real hot they tend to lose efficiency and the 4.8 scfm could drop as much as 30% or 40%.

Later Larry