Spray Equipment

[tvgordon]

I read in Fine Woodworking that compressor driven hvlp guns deliver a better finish than the turbine models.
Do you guys with agree with that?  I would have to purchase a compressor, mine is too small, so what is the minimum size I should buy?  I would like to have a portable one rather that a stationary one, any favorites?
I was looking at the 30 gallon models from Sears, Porter Cable, etc..  I plan on spraying water based finishes.
Tom.

 

[Lou Miller]

Not exactly my area of expertise, but I gave up on using the compressor driven guns. I just couldn't seem to find a filter that would remove the moisture from the air lines. Generally speaking though, I do agree that that the compressor driven guns give a slightly nicer finish. I have a 60 gallon compressor, but it gets used for many things other than finishing. Best way to decide on a compressor is to buy the tool that will use the most air, and then match the compressor to that. Spray guns are all over the map in terms of how much CFM the need.

Anyway, I'm using a Fuji Q4 for my spraying now and I'm pretty happy with it. There's certainly more of a learning curve I think, but once you get the bugs worked out, it works really well.

 

[bolson]

If you can't afford the Fuji Q4, Fuji sells an identical model as the Q4 called the MiniMite 4.  The only difference between the Q4 and the MiniMite 4 is that the Q4 has a "quieting" feature (hence the "Q").  The turbine and gun are identical other than this other than the blue color of the MiniMite

I've used compressor driven guns and turbine guns and I really don't like compressor guns.  Moisture and with some compressors oil is always a problem.  Even more so, I can take my MiniMite out into the yard to spray or spray in place.  You can't do that with a compressor driven gun.

The MiniMite series is also very compact and fits into my trunk.  I've done a few on site finish repairs for some friends and I just brought the set up with me to do it since I don't have a truck (I am a hobbyist).

But I would advocate laying out your needs and then finding a system to meet your needs.

 

[eweber]

I also own the FUJI Q4 and I am very happy with it.
Portability and simplicity were the main factors that made me choose a turbine driven system against conversion gun.

Portability was important for me because I don't have a spray booth so I wanted to be able to spray outside when possible.

As for simplicity I started to get overwhelmed by all the different factors and conflicting reports regarding conversion gun. Which compressor to buy which gun what filter to use etc. With a turbine system everything is plug and play.

I had the opprotunity to try a FUJI unit before buying it and I was able to get some very decent results right away which made up my mind.

 

[ccmviking]

I use a 60 gallon compressor and an HVLP gravity feed gun.  This is the gun I use this gun  (http://www.spraygunworld.com/products/CAT/CAT%20Jaguar%20SLP.htm)  with the 3M PPS System.  The gun spray's better than any one I'd used previously (binks 2001, binks 7, Devilbiss)  and clean up is a breeze.  You can pay 2-3 times more and get a SATA (which are THE BEST) but it won't be that much better if you're on a budget.  I got my gun with different needle air cap combo's for spraying stains and clears.  My finishing is better than about any that I see out in the wild.  Anyone with a gun should get the PPS system, and don't every get a gun where you can't fit it on there.

Chris...

 

[Greg_R]

I'm not a finishing guru but I can say that I really like my IR Garagemate compressor.  It is "portable" because it has a handle and wheels but I wouldn't want to cart it around to job sites every day.  It also comes with a lot of extras (that other compressors make you buy).  Definitely look for:

- rated for continuous duty
- oil lubed
- enough air flow for your gun (and any other tool that you might use).

 

[Jerry Work]

Hi Tom,

I wrote a manual available at www.targetcoatings.com that addresses these questions.  For the manual I assembled a focus group of folks from beginner to professional who hand not used water based finishes before and had them spray with a number of different compressor conversion and turbine guns.  At the end of the day I asked them to rank their preference and published that along with my own experience and preference.  The bottom line is that turbines are far less sensitive to viscosity changes in the sprayed material.  Conversion guns are very sensitive to viscosity.  For users who have a lot of experience with getting the viscosity bang on, and who have quality dryers in the lines, the compressor conversion guns produce a finer fan pattern and will lay down a smoother coat.  Think professional car painters here.  For folks who are less skilled in viscosity control or who do not have quality line dryers there is no question that the turbine guns will work better for them in most cases and in all cases can lay out a finish as fine as all but the very best of the compressor conversion guns.  Just be sure you buy a 4 stage turbine.  Contrary to the experience of the author of the FWW article, I find there is a world of difference between three and four stage turbines for everything beyond really low viscosity materials like water, dye, and non-build oil based finishes.  As the viscosity goes up to the range of build oils or water based materials the four stage is far better.  I have both a four stage turbine system and gravity feed and pressure cup conversion systems in my finish room.  Day in day out I use the turbine gun 80% of the time.  When doing a full fill finish (the finish fills all the pours of the wood so you see a perfectly flat surface, usually highly polished) I do the final top coat with the conversion gun and the material thinned out to a very low viscosity state.  One hint is to always remove the little plastic filter in the bottom of the gravity feed cup found in most conversion guns in order to spray viscous materials.  Those things are made for low viscosity auto paints, not wood finishes.  While it is possible for some to achieve descent results with cheap conversion guns (aka Harbor Freight and the like), high quality guns in the $400 to $800 range are far better.  Turbine brand makes far less difference than the difference between three and four stage turbines.  On the compressor size question, bes sure not to exceed the duty cycle of your chosen compressor or you will simply burn it up.  Most "oil less" compressors have a duty cycle of 50% or less and they put out far less air than you might imagine.  Also far less than most conversion guns like.  Hope this and reading the manual will help.

Jerry

I read in Fine Woodworking that compressor driven hvlp guns deliver a better finish than the turbine models.
Do you guys with agree with that?  I would have to purchase a compressor, mine is too small, so what is the minimum size I should buy?  I would like to have a portable one rather that a stationary one, any favorites?
I was looking at the 30 gallon models from Sears, Porter Cable, etc..  I plan on spraying water based finishes.
Tom.

 

[tvgordon]

Thanks for your input guys!  I like the idea of an all-in-one turbine system, but I also know I would use a larger compressor for other things than finishing.
From what you have said I will start looking a turbine systems.
Jerry, I will also look over the manual at target coatings website.  If it is as good as your Festool manuals, I'm sure I'll learn a lot.  Do you use Target's finishes in your shop?
Tom.

 

[Jerry Work]

Hi Tom,

Yes, I use them exclusively as I find them better from my experience than any other water based finishes I have tried over the years.  Since my studio and finish room are in the same building with our living quarters and gallery, my wife and customers really appreciate not smelling the volatile organics from oil based finishes.

Jerry

Thanks for your input guys!  I like the idea of an all-in-one turbine system, but I also know I would use a larger compressor for other things than finishing.
From what you have said I will start looking a turbine systems.
Jerry, I will also look over the manual at target coatings website.  If it is as good as your Festool manuals, I'm sure I'll learn a lot.  Do you use Target's finishes in your shop?
Tom.

 

[Dave Ronyak]

I purchased a Fuji 4-stage turbine unit last week from Phelps (Wisconsin) and put it to use this past weekend spraying Target Coatings (Oxford) brand WB shellac and lacquer on a pair of cabinets I made for my garage/shop.  Seehttp://www.phelpsrefinishing.com/SE4.html.  I purchased a package including a 3-mini-cup set, extra flexible leader hose, and wire mesh paint cut filter screens.  (These screens have much more filter area and internal volume than the ones typically supplied by the spray gun manufacturer.)  I did a lot of shopping around and reading before making this purchase, and was leaning toward the Accurspray unit that has the built in wheeled cart, but it would have cost >2X as much.  I think this is a very good price for a quality unit, and contrary to some magazine reviews which evaluated the XT gun, the XT-2 gun supplied with the ~$550 SE4 package easily adjusts between a traditional fan pattern and a smaller cone pattern.  I did not thin any of the coatings.  I strained them using a fine strainer and found nothing in the strainer at any time.  This 4-stage unit is reasonably quiet - I did not find a need to use any ear plugs since the turbine should be located away from the spray gun, and Fuji supplies a long hose (garden hose threads).  At this low price, I figured if the Fuji gun did not function as well as I expected, for the price I paid, I could buy another gun from Accuspray or Turbinaire, etc. and still be money ahead.  According to Jeff Jewitt from whom I puchased my WB coating supplies, Fuji makes a good gun.  Jeff (Homestead) is a dealer for Accuspray equipment.

I had no issues using the HVLP equipment or the WB coatings, even though this was my first experience with either.  I do have some experience with conventional HP compressor based spray equipment, spraying nitrocellulose lacquers for furniture and various automotive coatings, but if I can do it, anyone can.

The only clean up needed was to blow the dried powdery residue from the window screen after I was done.  It came off easily and completely.  My "spray booth" was made of pieces of old corrugated paper boxes taped together to block off a section of my garage, with an ordinary 20" box fan set in the window with a high quality furnace filter taped to the front of the fan.  As Jerry has said, most of the overspray is dry before it settles.

Dave R.

 

[tvgordon]

Thanks for the link Dave.  That looks like a really good price on the Fuji system.  It will probably be sold out before I get an extra $550.  It is a nice savings over the Q4 I had been looking at.  I also like that they offer packages with the most popular accessories included with the system.
Tom.

 

[GreenGA]

I was thinking about getting a cheap,

 

[Dave Ronyak]

The Fuji system I wrote about and purchased is a true HVLP system.  The included spray gun is not designed for use with a regular compressor.  If you want to use your Emglo or another compressor, and HVLP or near HVLP (aka HTE), you need to consider a conversion gun.  A conversion gun takes input air at a much higher pressure than is produced by even a 4-stage turbine unit and converts it to lower pressure (and thus much higher volume within the gun.  Jerry Work's excellent article linked to the Target (Oxford) Coatings website explains the key differences in turbine and HVLP and HTE guns.  He includes both HVLP turbine systems and conversion guns operated off ordinary piston and diaphragm types of air compressors.  You can find a lot of information on the internet about conversion guns if that is the route you want to go.  Eastwood and others offer conversion gun kits at various price points, and several manufacturers make HVLP conversion.  Here is a link to a site that offers conversion guns. http://www.spraygunworld.com/products/Astro/Astro Pneumatic - QULWood2.htm  If you look around this site, you'll see they also offer guns designed for relatively small output portable compressors.

Dave R.
Dave R. 

 

[Tim Sproul]

  Conversion guns are very sensitive to viscosity. 

Jerry,

You are certainly much more the experienced expert and I am the novice wanna-be....but is this really true?  I don't find my conversion guns to be very sensitive to viscosity.  I don't have any experience with turbines...but I had been led to believe that turbine guns were more sensitive to viscosity because you got as much air into the gun as the turbine could give.  Conversion guns have the option of going non-HVLP by increasing the pressure and hence can compensate for more viscous material by increasing the amount of air.  Here is what I thought was true:

turbine - change viscosity of finish to match the gun.
conversion - change pressure to match the finish.

Obviously, things like the orifice size and such make a difference but the above is considering if you had the same finish and the same n/n.

 

[Jerry Work]

Hi Tim,

As you can imagine there are a number of variables so my generalities are based on my own experiences and what I have observed watching/teaching others. 

The first major variable is whether the gun has a pressurized pot or is a gravity feed gun.  Pressure pot guns seem less sensitive to viscosity in terms of getting the material into the atomization zone than gravity feed guns but that alone does not necessarily lead to good atomization/good flow out with any given material.  Most all turbine guns are pressure pot guns where the amount of cup pressure is designed in and not usually adjustable.  Most pressure pot conversion guns require the user to set the amount of pressurization air.  Most turbine guns are designed to produce no more than 10psi at the air cup (the def. of HVLP).  Conversion guns are all over the place.  The good ones designed for industrial use are designed to stay within the 10psi at the air cap level although some for use outside of CA (usually called something like high transfer efficiency) go beyond 10psi.  Many of the cheap conversion guns are no where near 10psi and can easily be adjusted to go way beyond that.

With most solvent based materials your observation "turbine - change viscosity of finish to match the gun.
conversion - change pressure to match the finish." is usually correct as adding pressure either to the pot or to the air stream has relatively less effect on the subsequent flow out.  With water based materials adding pressure to the pot or air stream can have a significant effect on flow out as more pressure can cause the materials to begin to dry too quickly, before they have time to flow out and level.  The result will be orange peel.  The other danger is getting too much material on the work piece (too heavy a coat) which similarly impedes good flow out and leveling.  Too much material can also lead to surface cracking as the top of the coat dries before the center and bottom of the coat.  As the inner portions of the coat begin to dry they can stress the still fragile top surface causing it to craze or crack.

So, getting the air at the cup, the pressure in the pot, the viscosity of the material and the flow rate of the material all set properly and using the correct workpiece-to-gun distance as well as gun movement speed are important for a quality finish.  In the hands of an experienced pro these adjustments seem second nature and they will get it right whether conversion or turbine gun is in their hands.  In the hands of the less experienced it can seem like a daunting task.  I find that the descending pressure settings and limits present in most pressure cup turbine guns make them far easier for a less experienced person to "master".  And, they tolerate differences in viscosity more easily than most conversion guns, especially the gravity feed types.  That leaves most of the learning curve focused on workpiece-to-gun distance and gun movement speed.  Both are fairly easy to master quickly.  Hope this helps.

Jerry

  Conversion guns are very sensitive to viscosity. 

Jerry,

You are certainly much more the experienced expert and I am the novice wanna-be....but is this really true?  I don't find my conversion guns to be very sensitive to viscosity.  I don't have any experience with turbines...but I had been led to believe that turbine guns were more sensitive to viscosity because you got as much air into the gun as the turbine could give.  Conversion guns have the option of going non-HVLP by increasing the pressure and hence can compensate for more viscous material by increasing the amount of air.  Here is what I thought was true:

turbine - change viscosity of finish to match the gun.
conversion - change pressure to match the finish.

Obviously, things like the orifice size and such make a difference but the above is considering if you had the same finish and the same n/n.

 

[Corwin]

Hey Dave, Thanks for the link!  Just ordered one today.  And yes, they are going fast.

 

[Dave Ronyak]

Corwin,  I hope your experience is as good as mine has been thus far.  That dealer was very responsive to my questions, both before and after my purchase.  So was Southern Tools whom I queried about Turbineaire systems.  I have not tackled any other spraying projects since the shop cabinets.  Since Fall and cooler temperatures and rain have now returned to Ohio, I probably won't be using it, at least not with WB coatings, for a few months.  Although I have the capability to heat my garage/shop, I don't want to pay to raise the temperature to Target"s (Oxford's) recommended minium of 65 degrees F for WB coatings.  I have some solvent base NC lacquer that I may try, and know how to make it flow out decently at lower temperatures.

Please share your experience after you try your new HVLP system.  And don't forget to wash your glasses/goggle after you're done spraying!  I did until ~36 hr later, and I was using a pair of prescription glasses with polycarbonate lenses (from Lens Masters).  I succeeded in getting most of the overspray off them by soaking them for about a day in water to which I had added a few drops of liquid (Dawn brand) detergent, then gently scraping the surface of the lenses with my wet fingernails.

Dave R.

 

[Eli]

Anybody have any experience with the Apollo A1000Q?

 

[GreenGA]

Dave,

I also thank you for the reference.  I ordered mine on Friday evening and it should be at the house sometime this week.

First thing to shoot are the 12 louvered doors for the dressing room closets.  After that, well, I hope a cabinet or two will be ready.

Again, thanks.

 

[rodwolfy]

Corwin,  I hope your experience is as good as mine has been thus far.  That dealer was very responsive to my questions, both before and after my purchase.  So was Southern Tools whom I queried about Turbineaire systems.  I have not tackled any other spraying projects since the shop cabinets.  Since Fall and cooler temperatures and rain have now returned to Ohio, I probably won't be using it, at least not with WB coatings, for a few months.  Although I have the capability to heat my garage/shop, I don't want to pay to raise the temperature to Target"s (Oxford's) recommended minium of 65 degrees F for WB coatings.   I have some solvent base NC lacquer that I may try, and know how to make it flow out decently at lower temperatures.

Please share your experience after you try your new HVLP system.  And don't forget to wash your glasses/goggle after you're done spraying!  I did until ~36 hr later, and I was using a pair of prescription glasses with polycarbonate lenses (from Lens Masters).  I succeeded in getting most of the overspray off them by soaking them for about a day in water to which I had added a few drops of liquid (Dawn brand) detergent, then gently scraping the surface of the lenses with my wet fingernails.

Dave R.

Dave,

Thanks TOO! I ordered the system you got today. I went to the woodworking show in Seattle last week and had the Apollo 1025 system on order. It was going to cost $1090. I read an old Wood Magazine review and spoke with some people since. The Apollo is a good system, but not $400 better than the Fuji. The Apollo is louder too.

While at the show, I listed to one of the Wood Magazine editors while he did a couple of shows on finishing. He went to Turbine HVLP about ten years ago. He routinely sprays in the middle of winter in the midwest. He said that its like only 10 degrees out. You could too. The trick he said was to give your finish more viscosity by warming it up prior to use. He said that if it's 75 to 80 degrees just before you take it outside to spray, it will lay down perfect. Then you take it back inside to dry in the warm house (he sometimes gets complaints from the wife when its an oil based finish in the house that's drying.  )

Maybe you could give it a whirl?

Thanks again,

Rod