Spray Finishing - HVLP v. Airless v. Air-assist


I'm just starting to research a legitimate spray finishing system and was immediately surprised to read that HVLP is no longer the king of the hill. Now I've got Kremlin Airmix and Asturo on the mind, not to mention airless if I don't mind the hard edges or something. I'm not sure what my question is, if any, other than I think I'm going to be spending some time on the net and was hoping some of you who've already done the research may have some links for me. Thanks.
JP ************************** I want it all.
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www.homesteadfinishing.com has a forum dedicated to spraying, might be worthwhile to looksee.
wrote:

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snipped-for-privacy@vcoms.net wrote:

That's Jeff Jewitt's site IIRC....I'll definitely check it out. Woodweb has some good forums too, which is where I started to suffer from information overload. It looks like there was a book published back in 1996, but I've got to figure a lot has changed since then. Probably couldn't hurt to arm myself with that knowledge though.
JP
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Perhaps an over-simplification, but.... A LOT of my spraying headaches went away when I switched over to pot-feed. Aside from a few line-losses when cleaning, to be in control of the material feed is a treat.
What I do, is turn off all the air at the gun, but leave the air-supply to the pressure pot (both 2litre and 2gal pots) on. Then I pull the trigger and watch for a nice stream of lacquer. If I shoot the stream from chest-height, the stream lands about 4 feet from my feet. Then I turn on the air at the gun, blowing that nice stream of liquid to a nice fog and adjust the fan shape. Then I throw the two hoses over my shoulder and I can spray inside a cabinet, upside-down in small quarters. That worked best with a proper DeVilbiss HVLP gun. (not cheap).
Most guns allow for a potfeed...even a gravity fed gun can be fed by a hose from the top.
In a word:... syphon feed sucks.
My opinion.
r
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Jay Pique wrote:
<<I'm just starting to research a legitimate spray finishing system and
was immediately surprised to read that HVLP is no longer the king of the hill. Now I've got Kremlin Airmix and Asturo on the mind, not to mention airless if I don't mind the hard edges or something. <<
And indeed, what a slippery slope it is. I would have to say that the best way to find out what suits your needs it to identify the bulk of what you will be spraying, what type of material you are spraying, and how often you will be doing it.
I have spent hours on this subject and worn myself out. I am a glutton for facts, but having made my living in the trades for some time now I found years ago that nothing beats talking to someone that uses a product on a regular basis. Some things seem to work better than they should, and some don't work as well as expected.
That being said, my parameters were to find a >portable< system that would spray (with the appropriate air caps) conversion lacquers, industrial coatings, varnish, stain and dyes, and urethanes. Key here being portable, and a strong leaning to "professional" (which usually means quick dry, conversion or high solids) type finishes.
I tried conversion guns, but the overspray was not acceptable. When properly thinned, the finishes from some of the low cfm requirement guns was amazing. And the overspray was about half that of my regular high pressure setup. But for me to drag out to my client's house to use inside, it was still too much overspray, too much drift in the air. The positive side was that the guns left a great "off the gun" finish, it was EASY to set up the guns, easy to clean them, and with the driers on the air lines I could use a good compressor and all my regular air lines.
Cost was good too, less than $300 for one of the guns, and one that was just about as good that was only $99. So I now use a similar air compressor powered setup for finishing doors for a local door company that has a spray and finish area (notice I did not say booth!) set up about 300 ft. from their showroom to keep the fumes out of their customer's noses. I can run a few hoses out to the spray area and spray away, without any concerns of overspray or drift.
However, having tried the turbine powered HVLPs, I was stunned how much less the overspray and drift were compared to my test HVLP conversion guns. I tried out the following and in some cases used the following guns. I have put some comments after the guns, not meaning to offend anyone. I know we are all proud of our equipment, and these are only my thoughts. I think that when you get up into the upper end of any HVLP systems you will be fine. I only looked at 4 stage units, except in the case one of the Graco systems that was a three stage.
Accuspray: Liked the unit overall. Liked the finish left from the gun, but was only able to shoot latex at the contractor demo. Although this gun has been in production (according to the conversation I had with Mr. Jewitt) for about thirty years with no problems, AND has a lifetime warranty on the gun body itself if you get the right one, I just didn't like the plastic gun. And looking at replacement parts, accessories and consumables, they were in my opinion too expensive when compared to others. Local servicing available on a limited basis.
Apollo: Liked the finish left from the gun. I absolutely hated the bleeder gun as it was always "on", blowing air and dust around too much for my taste. I have never liked bleeder guns for anything, so this wasn't a serious consideration.
Turbinaire: I thought this was the best feel and balance of the lot of guns; it was really nice. The Turbinaire rep did admit that they didn't make their own gun (who cares?) and that it was a refit of an older model. But man was it nice; easy to adjust, and left a good finish off the gun. The Turbinaire rep (a great guy BTW) got frisky and actually shot unthinned latex paint from a can I watched him open. Worked great. Price on consumables and accessories still a little high, but I liked the system overall and thought it was a great value. Came with a 6' whip included in the price. Turbinaire guy admitted that the speed control on the model he showed me was a little gimmicky, but did have its place. On the accounts he serviced he told me his clients turn on the machine, open up the dial to full blast and leave it there. No local repair or support for this system was available.
Graco: They no longer off the system that was recommended to me by a friend of mine that uses his for full time refinishing. He shoots mostly conversion lacquers, varnishes, urethanes, tints and dyes, and loves his gun setup. Graco tech support is everywhere, and the Graco rep told me that they have about 500 tech support guys on the phone lines so you can call and talk to a live person just about anytime you call. I was not able to try this setup as they weren't allowing demos at their seminar. However, the offsetting factor here was great BBQ with homemade sausage that was fresh off the grill. The guns setups they had seem quite reasonable, and local service and accessories were readily available.
Capspray: Didn't like the setup or the old designs. The turbine was much too bulky when compared to the other units (which all use the Amtek - Lamb turbines) and it was an awkward feeling the design. The guns felt cheap, and the guys at the seminar didn't know that much about it or the availability of the accessories as they were there to sell the airless setups.
Earlex: Plastic, plastic, plastic. The 3 stage I tried was made in the US (other come from UK), but came with short hoses and plastic turbine housings, and was just cheap feeling all the way around. I had the feeling it was a $39 shop vac with a garden hose and a gun attached. It may have been.
Fuji: I found out about this gun when I was participating in another forum a couple of years ago when this subject came up. This is the one I actually decided to buy. I like the quieter turbine, and the gun is convertible to supply air from top rear of the handle or below in the grip as usual. You can also turn this into a gravity feed gun (the only HVLP in this group to do that) if that is what you require which I will do since I spray some doors and other projects horizontally on sawhorses. It has very reasonably priced consumbles and accessories, and while the repair support is not local, every time I have called their HQ in Canada I have talked to the owner, Paul. I am buying straight from one of his distributors, which has made the price of this unit not only affordable but has also raised my confidence in problem resolution since like Paul, his distributor answers the phone himself. The distributor used the equipment for years as a professional refinisher before he decided to rep the product, and his commitment to service seems as sincere as the owner's. His distributor is not a salesman; he is a no nonsense midwesterner, and while he could answer any question put to him, he never actually even tried to sell me the Q4 system. I liked the no nonsense, no hassle approach.
Both owner and distributor know the guns inside out, and just about all the consumables and replacement parts are available overnight. Apparently they have been running their business this way for years.
I like the fact the unit is available with package pricing, and that the more you buy the better price you get. I need one portable system that does it all, so I am buying the package with all the aircaps and needles available, the gravity feed conversion, an extra whip, etc. Also, it is tough to beat the Q4 price since they also sell the unit with free shipping, including free shipping for the accessories purchased with the original order for the system. Once again, I really like the fact that the consumables and repair maintenance parts are so reasonable.
I looked at the Kremlin, etc., briefly, but it is not made to be easily portable. I also had a nasty case of sticker shock when I looked, but hey, I had to look. But I have never heard anything but the best about the Kremlin line for those that need that kind of high volume finishing solution.
Hope all that helps out Jay. Or to anyone else interested in a new finishing system.
Robert
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I have snipped most of Robert's post but included his info on the Fuji Q4. My research wasn't nearly as exhausting having consisted mostly of word of mouth, tool reviews and information gleaned from web sites. I have the same unit and have had the time to do quite a bit of testing. I concur with all of Robert's remarks. I have several photos of the unit and some of the tests I did if anyone would care for me to e-mail them. (you will need a broadband connection) I have no connection with the Fuji company other than as a satisfied customer.
Max (e-mail address should be obvious, remove the "not".)
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Just to correct a few things re: AccuSpray's HVLP guns 1. they now have a siphon gun 2. they make a pressure pot for their AccuSpary 10 gun 3. HVLP turbines heat the air as they compress it and that air can make an aluminim gun quite warm, if not downright hot. AccuSpary's Delrin gun ( the fluid path inside being stainless steel ) doesn't conduct that heat to your hand. 4. drop an aluminum gun and it can crack - not so the Delrin gun.
The duty cycle of an HVLP turbine is affected by its motor cooling and its bearings. The former is a function of the units air filters (plural) - one for the air going to the gun and one for the cooling the motor. If the filters are difficult to change you're apt to only change them when the turbine performance falls below a useable level. By that time the motor and bearings may have been damaged, assuming the unit used bearings rather than the cheaper bushings.
The AccuSpray 230 three stage turbine has a duty cycle of 4 continuous hours of use. The 230 puts out 110 cfm at 7 psi (one of, if not the highest, psi of the turbines Robert covered).
just some more things to think about when selecting an HVLP system.
The April/May 2006 issue of Wood magazine had an evaluation of 10 HVLP systems.
charlie b
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charlie b wrote:
<<The April/May 2006 issue of Wood magazine had an evaluation of 10 HVLP systems.
charlie b

A good jumping off point to start looking, but it had many inaccuracies as verified by my personal conversations with factory reps from Accuspray, Turbinaire, and Fuji.
For example, they stated that the Fuji would not shoot a one inch width pattern. Untrue. I have photographic proof from Max from above who took the time to test, measure and mail me some great pics. Thanks again, Max.
They tested the ability of shoot unthinned products and thought that was a very important point in deciding the value of the guns. Every single rep that I talked to told me that they wished they had not used that test as they felt like people would think that they could simply put finish in the gun and start spraying.
They are anticipating returns and the possibility of lots of time with tech support working folks through unsatisfactory finish. This will really be a problem with folks like me that are used to spraying with high presssure as there is never a problem with atomization (with properly prepared material!). It will not be the gun or system's fault, but rather a poor test that leads to incorrect conclusions.
All told me "thin as usual". Since HVLP delivers bigger droplets of finish, you almost have to thin in order to get the material to lay out correctly. As charlie b pointed out, the turbines generate warm air, and this further speeds the drying of your finish. If you don't thin or retard in some way depending on your finish, you will be spraying warmed, large droplets onto a cooler surface. It may lay out some, but not to the potential of the material when properly thinned.
If they wanted to test the power of the turbines (of which Fuji, Accuspray, Turbinaire, and Apollo all use the same Amtek Lamb) and their different configuration they should have used the Oreck test and tried to pick up a bowling ball by connecting to the other end. It would have had the same relevance. Maybe more.
As with any major purchase, it is always important to do the homework you need to do before purchasing. But nothing beats talking to and handling the products. Simple phone calls to the tech support of some of the companies in the magazine article changed my ideas of what I read. Best of all, they were able to tell me where I could see their product in my area. It took three months to be able to handle all the guns mentioned in my earlier post, but it was worth the wait and aggravation.
Robert
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snipped-for-privacy@aol.com wrote: <snip of good, informative post>
Thanks for all the feedback everyone. My initial hope was to get a single portable system that would handle all of my finishing needs. The ability to spray latex paint is important, and the thicker the better so I don't have to use multiple coats. This pushes me towards airless, I believe. But I also really need the ability to lay down flawless clearcoats as well. Something tells me that I can't go wrong starting with the Fuji Q4 as a pretty good all around unit.
JP
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snipped-for-privacy@aol.com wrote:
RE:The April/May 2006 issue of Wood magazine had an evaluation of 10 HVLP systems.

Ain't that almost always the case? There's almost always a way, albeit sometimes pretty tricky, to make something do what you want it to do - if you want to spend the time finding the way.

snip

Couple of comments
There are water based finishes developed specifically for spraying - right out of the can and some even specify that it's not for brushing on. Some of these finishes even specify that it SHOULD NOT BE THINNED - at all.
I wouldn't want to try spraying a 3, 4 or 5 pound cut of shellac but it's almost expected that you'll thin the "right out of the can" shellac. Not so with poly or lacquer, catalyzed or not.
I guess it's the Expectations vs Reality thing. I don't want to HAVE TO thin any clear finish I want to spray. I don't want to play with viscosity cups or sticks, thin a sample batch, shoot a test, adjust the thinning ratio, shoot a test, tweek the mix and shoot a test - THEN spray my piece.
I HAVE TO adjust the air/finish mix and that takes some test spraying. I don't want to HAVE TO futz with the finish/thinner/ retarder/flow out stuff mix as well.

Ah- but what about the bearings/vs bushings /duty cycle thing? And two filters, one coarser one for the mnotor cooling air and a finer one for the air going to the gun - that's important - to both the quality of the finish as well as the lifespan of the turbines. If they ain't easy to change, one may put off changing them - until LONG after they should be changed.

Given all the clear finishes - and paints - folks want to push through a gun, finding a way to "test drive" the final 2 or 3 choices using the range of finishes you think you might want to use would take some real persuassive talking to store owners or factory reps.
Let's face it, there is no Swiss Army Pocket Knife when it comes to spraying finishes. If you want to shoot thick stuff - get an airless. If you want to shoot clear finishes, any of the HVLP systems in the $700-$800 range will probably meet all your needs. In that price range it comes down to things like "siphon vs pressurized cups/pots vs gravity feed" and "bottom of the handle vs back of the gun vs both" air line connection points and ease of clean up. Depending on what kind of stuff you'll be spraying a finish on, one may be better for you than another.
charlie b
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