Advice on a HVLP spray system

[Tim J. Chase]

Would I be better off purchasing a Turbine system or get a larger 60 gal. compressor that could keep up with a Porter Cable PSH1 HVLP gun
considering a two stage Kobalt 60 gal compressor.
  This will be used for a kitchen cabinet project doors and drawers only, as well as small furniture and bowls from lathe in the future.

thanks for the advice
Tim

[Rob Young]

Would I be better off purchasing a Turbine system or get a larger 60 gal. compressor that could keep up with a Porter Cable PSH1 HVLP gun
considering a two stage Kobalt 60 gal compressor.
  This will be used for a kitchen cabinet project doors and drawers only, as well as small furniture and bowls from lathe in the future.

thanks for the advice
Tim

Consider if you have other uses for the compressor such as pneumatic tools and you plan to use them frequently. 

Consider that you will also need to add things like the air line as well as oil and moisture traps.

In my case, I decided that I don't use pneumatic tools much so I went with a 4-stage turbine (Sprayfine).

[Rob Young]

Consider if you have other uses for the compressor such as pneumatic tools and you plan to use them frequently. 

Consider that you will also need to add things like the air line as well as oil and moisture traps.

In my case, I decided that I don't use pneumatic tools much so I went with a 4-stage turbine (Sprayfine).

Should point out the cost of the Sprayfine 4-stage is $600 including a pressurized cup gun and hardware so that you can reconfigure the gun so the cup is remote. This gun is compatible with the 3M pps system so it can be converted if the appropriate parts are purchased. I have not bothered to convert mine.

This is also a bleeder system so the gun is always blowing air. This is part of how the cost difference is achieved. For some, having a bleeder gun is a problem but I've learned to use it and so far, no complaints. In theory, the turbines last longer in bleeder systems because they don't see the back-pressure. Non-bleeder guns require that the turbine have some kind of relief valve. The A401 can use a non-bleeder gun but it is recommended to turn off the turbine if gun is not going to be used for more than a few minutes.

In (an unscientific) comparison to an older 4-stage Apollo (which is a non-bleeder system), mine runs a bit cooler in that I have no problem holding my hand on the turbine case after the unit runs for 20-30 minutes. The Apollo case felt hotter, wasn't at all comfortable holding hand on it. Very objective criteria of course.

But at $600 for the kit plus $30 for N/N sets it is quite affordable.

Replacement parts such as diaphragms and one-way valves for the pressurized cups are reasonably priced.

A similar 4-stage Fuji with a cup-under gun is between $800 and $850. I believe the Fuji Mini-Mites are non-bleeder designs. There is a value priced Apollo line in about the same price range as the Fuji. Earlex has a 3-stage system (not sure if bleeder/non-bleeder status) for about $600.

[jteneyck]

If you don't need portability an HVLP conversion gun, or two or three, driven by a compressor has more versatility than a turbine.  The lower range turbine units will be cheaper, but once you get up to a 4 stage Fuji you're talking just as much money as a mid range HVLP gun + compressor.  The real problem I found was that unlike the turbine packages where everything is paired together you are pretty much on your own putting together an HVLP gun, compatible compressor, and accessories.  After driving myself nuts I finally decided to just take the plunge and start simple.  Turns out, you don't need to get too fancy to get great results.  The key is to make sure the compressor has enough flow to handle whatever gun you want to use.  Next is to decide on a gun, or two, that will be able to spray the products you want.  I started with a package of 3 cheap guns that cost about $120 total and used them for several years.  Eventually, I upgraded to a pressure feed gun when I wanted to spray paint and I use that gun to spray pretty much everything from dye to paint now; it's that versatile.  Since I only spray waterbornes and shellac I don't need any special filters, chillers, or driers on the compressor.  I use a stock regulator/separator at the compressor, another to step down the pressure at my temporary spray booth, and a cheap in-line water/oil filter at the inlet to the gun. Never had a problem.  

If you go with the HVLP + compressor approach I highly recommend using the 3M PPS cup system with whatever gun you choose.  In fact, I highly recommend it with a turbine gun, too.  
John

[CEPenworks]

For what you are planing on spraying don't get caught up in needing a large compressor. I have been using a 2HP Craftsman 10-15gal compressor to do my spraying. I started with the HF purple gun and continue to use that gun for shellac. Several years ago I upgraded to a QualSpray gun form homestead finishing products. I have the gravity version of Johns pressure feed gun. I only spray shellac and waterborne finishes. I just have a regulator on the tank which is usually wide open then a regulator and a separator on the gun. The compressor may turn on while spraying but because the gun is running at a much lower pressure I have never run out of air.

[Cooler]

I have a HVLP system.  Very little overspray and it lays down a nice finish. 

A standard gun will create much more overspray.

[Snipe Hunter]

I prefer a bleeder gun. A turbine system needs to bleed somewhere or the turbine will overheat. So it bleeds at the gun or through a bleeder valve at the turbine. The problem with bleeding at the turbine is that it will stir up dust wherever the turbine sets. If it bleeds at the gun, simply hang the gun away from any dust collecting surfaces. There's always dust in a home or garage. I prefer shooting outdoors, in the shade where dust is minimal.

As for turbine vs. conventional compressor systems, I prefer conventional. They atomize better than a turbine system. I prefer gravity feed vs siphon feed. Gravity feeds better than siphons. Wood topcoats are thicker than automotive topcoats and feed better via gravity. Some gravity feed guns have a pressure tube from the gun to the cup cap. They feed even better.  

I say I prefer conventional, gravity feed conventional HVLP but I use AccuSpray (3M) Turbine, siphon feed guns professionally. For lots of reasons but none of them are because of finish quality. I can break down the AccuSpray guns and clean inside. If the EPA inspects my equipment, I know it is compliant. A conventional HVLP (also called Conversion gun) will only be compliant if my pressure is set right and my regulator is set right. I've found that when the guns are set to comply with the EPA HVLP standards... they don't lay out a nice finish. So I have to cheat. Also, all my equipment is in a mobile trailer and space is at a minimum, not enough space for a large compressor.

That being said, I can get a nicer finish with better atomization with a $20 Conventional, gravity feed gun (Conversion gun) and a $300 compressor than I can with a $300 turbine gun and a $500 turbine. So the economics of a conventional compressor and a conversion gun far outweighs the economics of a high quality turbine and turbine gun.

As for PPS systems. I use them because I'm doing production work and need to clean my guns quickly. Keep in mind, a box of PPS cups is about $90. The adapter and the cup itself will run another 80-$100.

The good thing about PPS is that it will deliver fluid, even if the gun is upside down. This can be nice for assembled cabinets.

If I were a "hobbyist", I probably wouldn't shell out $1000 for a good quality turbine, gun and PPS accessories. I'd buy a few cheap guns with various sized spray tips, air caps and cups and buy a compressor that delivers upwards to 7 SCFM at about 40 psi.

The Porter Cable gun noted by the OP is a Chinese gun sold under a ton of different brands and by a bunch of different retailers. Grizzly has a 2 gun set for around $50 which would do just about anything woodworking related.
TCP Global has a 3 gun set that will do just about anything you every want to do for $109.00. The nice thing about this set is the max SCFM requirement is 7.1 SCFM for the primer gun. The primer gun would be used for thicker wood finishes. So you don't need a huge compressor. You could probably get away with a 6 SCFM compressor and dial the gun down a hair. I'd seriously consider shopping craigslist for a used compressor for a couple hundred. 

TCP Global set
6.1 SCFM @40 psi compressor.

[Willyou]

To the OP, you don't specifically say but, I assume you already have a small compressor. If so, as alluded to above, check out LVLP guns. These work on lower pressure and volumes and will work well with smaller compressors. I only recently started spraying; mostly shellac and WB finishes. I use the Sprayit 352 from Homedepot. It requires only 4.2 cfm, and was less than $20. I also like the side feed swivel cup that allows me to spray at any angle without the extra expense of the PPS system. I believe this gun to be a knock-off of the Iwata W71. I purchased a second Iwata needle/nozzle set that fits just fine.

[hcbph]

Would I be better off purchasing a Turbine system or get a larger 60 gal. compressor that could keep up with a Porter Cable PSH1 HVLP gun
considering a two stage Kobalt 60 gal compressor.
  This will be used for a kitchen cabinet project doors and drawers only, as well as small furniture and bowls from lathe in the future.

thanks for the advice
Tim

I have this gun and it works well: https://www.harborfreight.com/20-oz-hvlp...62300.html
I added a regulator that allows more adjusting of pressure as desired.  I've shot a lot of finish with it successfully.  I drive it with a pancake compressor and though I don't typically spray continuous, it does keep up.  The only real down side to it is the plastic fluid holder but that is easy to solve.  HF sells a metal replacement that is well worth the upgrade.

[Cabinet Monkey]

n. A turbine system needs to bleed somewhere or the turbine will overheat. So it bleeds at the gun or through a bleeder valve at the turbine. The problem with bleeding at the turbine is that it will stir up dust wherever the turbine sets.

This doesn't seem very well thought through. Certainly you realize that the turbine is going to blow massive amounts of air regardless of whether it is a bleeder or non -bleeder ? The motor needs to be cooled regardless of type; and that air exhausts at the box every second it's running. If it's stirring up dust that ruins your finish, your spray space is too dirty to begin with. A bleeder gun may make it easier to deal with the problem immediately, but the underlying problem still exists.

For me, I think HVLP Turbines are easier and faster to dial in. It's not easy to find an affordable compressor that will deliver a lot of air consistently to run even an HVLP gun. Spraying shellac is easy. A craftsman 2hp ain't going to be very good at spraying thick waterborne cabinet paint like Kem-Aqua or Renner 2k. For those advocating compressed air, I also think too little emphasis has been put on what it really takes to get clean, dry air to the gun tip.

Thing about turbines no one has mentioned is they are LOUD. Very loud. You'll probably be wearing ear protection when using one. Another trick some use with them is to get a remote control to turn them off between spraying pieces.

For me 3M PPS is overrated for the hobbyist. Color changes aren't frequent and the cleanup time saved is minimal. You still have to clean the needle, aircap, and fluid path. Now, if you're spraying cabinets in place, the advantage of being able to hold the gun in any orientation you want, even upside down, can be with the cost. But for a couple of doors or a bowl every once in a while, it's gonna be a splurge.