Replies

1. 
   Howard_Acheson | Mar 14, 2001 10:02pm | #1

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   Tests reported in issue of FWW a couple of years ago indicated that a conversion gun produces a finer atomized spray with less overspray and will handle a wider range of finishes.

   Also, the heat produced by turbine guns will sometimes cause finishes to dry before it reaches the surface.

1. 
   Nick_Anzano | Mar 14, 2001 10:12pm | #2

   *Howard,Is this still true or have the manufacturers improved their turbine-fed guns. Don't get me wrong, if the conversion guns are better, I save around $400 since I have the compressor already. I just want to make sure I get something that will allow me to spray water based finishes and latex paints.Thanks for the info.Nick

1. 
   Michael_Richwine | Mar 15, 2001 05:30am | #3

   *Nick, There has been plenty of discussion on this subject, if you care to search for it.Take it from someone with over 25 years of professional finishing experience, both custom and industrial, 10 of it with various HVLP systems. I also have owned two of those $1000+ systems of very good quality, one of them a four-stage unit. Currently own two conversion guns along with a bunch of Binks and DeVilbiss conventional guns, and need to buy 2 more conversion guns.No turbine currently on the market produces anywhere near 10 PSI at the tip. The expensive 4 stage system I had produced just over 7 PSI with the hose blocked, and the pressure at the gun fell off rapidly when air was allowed to flow. This drastically limits the viscosity of what you spray, which leads to more coats to get the same build, and a greater tendency to sag and run. You also put more VOC's in the air from the excess thinnerYou can't alter the pressure to the gun with a turbine unit like you can with a conventional gun, although a few of them allow you to adjust air flow. This means when you spray dye stains you get clouds of unnecessary overspray, and yet have a hard time atomizing thicker finishes. Changing air caps helps somewhat, but with a conversion gun you can just turn the air down.Very few turbine guns allow the range of fluid flow and fan width adjustments that a conversion gun does, although some are coming closer.Turbine units are indeed lighter than a compressor, but my portable rolls in and out of my van easily, and you can use a much longer air hose than you can with a turbine. I've used up to 100 feet with my Mach 1. You just have to raise the pressure to compensate for line losses.Some turbine units put on a good finish with materials of the right viscosity, but none has the performance range and the value for your dollar that a good conversion gun does.There are plenty of second or third generation guns on the market that give excellent performance on 6 or 7 CFM of air, and cost less than half of a turbine setup. Sharpe 998HVLP in the low $200 range, and Asturo guns in the $250 to $400 range come to mind from personal experience, and the Binks Mach I also, with the correct air cap.When is the last time you saw a turbine gun use din an industrial setting? Never, i'll bet. Conversion guns actually pre-date turbine units, but the early setups from Binks and DeVilbiss required 18 to 22 CFM of air, and so weren't practical for smaller shops. That has long since remedied, and guns like Asturo give a "Class A" finish with very low air consumption, and a nice soft spray pattern.

1. 
   Bob_Canada | Mar 15, 2001 05:52am | #4

   *Michael;YOur HVLP comments have been a real eye opener for me, thanks. Is it possible to question you about proper painting for cypress wood? I'll be finishing an outdoor project in cypress that must pe painted. To the point, I plan to coat with a good acrylic latex trim paint. I'm just wondering if cypress really should be coated with a good primer first? I seems to hold paint really well I'm wondering about the need to prime. Thanks in advance

1. 
   Nick_Anzano | Mar 15, 2001 02:34pm | #5

   *Michael,Thanks for the input. It looks like I'll be going the conversion route. Makes a lot of sense once its all spelled out.

2. 
   Michael_Richwine | Mar 15, 2001 02:34pm | #6

   *Bob,I'm not really a painter -- I co custom finishing, usually "furniture grade" finishes, or else faux finishes like the Italians and French are putting on "designer" furniture.However, from my limited experience, primers help greatly with adhesion and durability, and reduce the number of finish coats needed. I always use them with latex and oil base finishes, and even with colored lacquers -- both conventional and catalyzed. Sealers have a similar effect under clear coats -- they promote better adhesion, and help level the surface and allow a better looking finish with fewer coats.One caution though: Don't try to build with primer or sealer. They are designed to be a bonding coat between the wood and topcoat, and extra coats can reduce the durability of the finish.

3. 
   Michael_Richwine | Mar 15, 2001 02:41pm | #7

   *Nick,You're entirely welcome. I hate to see anybody waste money.The deceitful advertising of many of the turbine manufacturers P's me off, too. "True HVLP" indeed! As if they were the only ones. And the performance figures are so misleading as to be blatant lies.That said, let me repeat: Within their limits, turbines CAN do a very good job, and some people are quite satisfied with them. But for me, it's too little performace for way too much money.

4. 
   Bob_Canada | Mar 15, 2001 04:23pm | #8

   *Once again thanks. Funny you should mention faux. I'm finishing the cypress to look like copper. I can't tell you how dissapointing it is to confess that all I have is a Wagner airless sprayer. I guess that will get me kicked off the site.

5. 
   Don_Stephan | Mar 16, 2001 03:46am | #9

   *Lots of information on spray equipment available on the Forum at http://www.homesteadfinishing.com, and the support after the sale is unmatched!

6. 
   Michael_Richwine | Mar 16, 2001 03:47am | #10

   *Bob,We all have to start somewhere. It's not what you have that's most important, it's what you do with what you have. Good tools just make the job easier.What technique are you using to simulate copper?

7. 
   Bob_Canada | Mar 16, 2001 04:33am | #11

   *About the copper finish. I do it backwards. I paint the entire piece with shutter green acrylic latex trim type glossy. Then ,using a china bristle brush, I wisk the copper lightly on top. I try to emphasize or wisk slightly more copper on high spots and less in the low areas of the subject. The copper is "DecoArt Patio Paint". It goes on pretty quick and uses tons less copper paint. Some would add a wash of patina (turquois green) to simulate oxidation. I think mine looks antique without it.

8. 
   scott_murray | Mar 22, 2001 10:53am | #12

   *Check with Fuji. On their web page, they mention a new conversion gun coming out in June which will need a lot less air due to new design (some kind of venturi set up). If you can wait till then, it might be a good deal, since you won't need a huge compressor to run it.