Spraying nitrocellulose lacquer with earlex sprayer

Several years ago, Chuck Moore pointed out an Earlex sprayer on sale that he had used for a while before upgrading to a more upscale system. I went ahead and bought one. While I've used the Earlex for paint on a number of occasions, I'm getting ready to spray a couple ukes with behlen's stringed instrument lacquer with it for the first time. Instructions say to wait an hour between coats, and I was wondering if people typically clean the sprayer between each coat, and if so, what is used to clean the sprayer. I have mineral spirits and some lacquer thinner, and probably a couple other solvents laying around. Also, is it a good idea to thin the lacquer before spraying with the earlex?

With nitro lacquer you do not have to clean the gun very often. Mainly just the air tip, as the small holes become obstructed. Keep them very clean, as even a small bit will disrupt the fan. Keep mineral spirits away from lacquer, acetone or lacquer thinner is the right stuff. Use the same solvent that you thin the lacquer with . I like acetone. Yes, you will almost certainly benefit from thinning the lacquer, even up to 1 part lacquer, 1 part acetone. I have not used the Behlen's stuff, so I do not know exactly. Thinning ratio is not really critical, but when you get it right, it definitely helps. Shellac makes a great under coater for lacquer, a couple of light coats, sanding each. A can of Bullseye brand shellac will work for a single uke, but practice a bit to get a feel for how the can sprays. If you mix your own shellac and use the same spray equipment, be sure to flush several times with acetone, before spraying lacquer, or you will get fisheyes. And, since you mention that you have sprayed latex with it, I would flush it really well with acetone, maybe fill the cup, spray, let it sit, spray, maybe let it sit overnight, or more, spraying... If you spray the acetone used to flush the spray gun against a clean surface, like a piece of cardboard, you can get an idea of any contamination in the gun/ cup. Strain everything before spraying, always. It is not a great idea to use the same equipment for lacquer, as for latex. Actually, the lacquer gun should be dedicated just for that purpose only. A spec of latex in your lacquer finish will ruin your day. If it happens, let it dry and sand it out. Sometimes you can pick it out when it happens, but you can make a lot of work for yourself real fast. Cleanliness really is crucial. Good luck.

I'm unfamiliar with the earlex rig, but lacquer is lacquer. Spray a sample board first, adding lacquer thinner until the fan lays out nicely. A 50/50 cut is probably typical, but heating the lacquer in a water bath permits a thicker mix. I just go with the 50/50 and adjust the fluid flow and the fan at the gun, diluting the lacquer more if I'm having a bad day. I spray a good coat, wait for the surface to flash off, then spray another coat, typically trying for four double coats in a day. After spraying, blow the lacquer back through the gun by covering the nozzle tightly with a rag. A quick dose of straight lacquer thinner won't hurt, but if I'm sure I'll be back in an hour I usually leave the gun alone. Clean it thoroughly at the end of the day, or as soon as you are done spraying for the day. I take off the nozzle, drop it into the thinners in the gun cup, and put the cup back on the gun over night. A fine spray gun is a delightful thing to use, but I've switched to cheap door jam guns for all my spraying, about $40 the last time I bought one at Lowe's. They get tossed rather than rebuilt. I grew up around all kinds of industrial spray guns, and I probably treat mine rougher than I should.

LMI has an article on its website with details about thinning ratios, how long to wait between coats, and when to sand between coats. I've used the Earlex to spray nitro, and while you can get a nice finish from it, you will spend a lot of time sanding out the orange peel. It didn't take long for me to switch to a compressor and spray gun.

Chris_H said:

With nitro lacquer you do not have to clean the gun very often. Mainly just the air tip, as the small holes become obstructed. Keep them very clean, as even a small bit will disrupt the fan. Keep mineral spirits away from lacquer, acetone or lacquer thinner is the right stuff. Use the same solvent that you thin the lacquer with . I like acetone. Yes, you will almost certainly benefit from thinning the lacquer, even up to 1 part lacquer, 1 part acetone. I have not used the Behlen's stuff, so I do not know exactly. Thinning ratio is not really critical, but when you get it right, it definitely helps. Shellac makes a great under coater for lacquer, a couple of light coats, sanding each. A can of Bullseye brand shellac will work for a single uke, but practice a bit to get a feel for how the can sprays. If you mix your own shellac and use the same spray equipment, be sure to flush several times with acetone, before spraying lacquer, or you will get fisheyes. And, since you mention that you have sprayed latex with it, I would flush it really well with acetone, maybe fill the cup, spray, let it sit, spray, maybe let it sit overnight, or more, spraying... If you spray the acetone used to flush the spray gun against a clean surface, like a piece of cardboard, you can get an idea of any contamination in the gun/ cup. Strain everything before spraying, always. It is not a great idea to use the same equipment for lacquer, as for latex. A spec of latex in your lacquer finish will ruin your day. If it happens, let it dry and sand it out. Sometimes you can pick it out when it happens, but you can make a lot of work for yourself real fast. Cleanliness really is crucial. Good luck.

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Good tips, Chris. I keep a large sheet of cardboard in the spray room, and it always gets a test shot before each session to make sure everything is jake. With cheap guns you can have a separate one for each material you expect to use. Behlen's lacquer is wonderful stuff. On a really hot day I find that I can cut it with some retarder but otherwise right out of the can. Everything you've said is the straight skinny.

Yes, I have dedicated guns for most things I spray. Every gun has a different 'flavor' different handling characteristics. There is a difference between guns.

What size spray tips do you guys use in your guns?? 0.08mm, 1mm??

All great info above. One thing I did with the Earlex was go to the smallest tip they have. For me that worked best.
In the summer it's hot enough even with the retarder I can't come right back to back and do a second coat. The lacquer is gassing off already and you will get bubbles showing on the second coat so for me, I have to wait maybe an hour and can come back then. You'll have to experiment with the lacquer/thinner/retarder ratios and you can get a really nice, smooth and glassy finish. I've gone to the Cardinal lacquer and I'm using the Earlex 5500. The couple of things I don't like about that system is that the air is always flowing through the nozzle and you can't control the size of the pattern but otherwise I think it does a nice job for a budget setup. I'll most likely upgrade to one of the Fuji setups in the future.

Beau, I'm using the 0.08mm. I have three sizes and that works best for me. I've never tried the Earlex with anything but lacquer.
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This is the Fuji I've been drooling over Fuji 2904-T70 Mini-Mite 4 - T70 HVLP Spray System

The lacquer gun I use with Cardinal (not that lacquer brands matter much when choosing tip size, just that I have a few different lacquer guns, for different lacquers) is an Accuspray HVLP Model 10, I believe (not turbine) with a #61 tip, which is 1.5mm, and a #807 air tip. It is set up on a pressure cup. It is my favorite gun ever for spraying lacquer, extremely friendly gun that just sprays glass all the time. I would not want a smaller fluid tip for lacquer. Not enough fluid flow means more passes to cover an area, which can translate to more texture in the finish. Say, for spraying the side of an uke, Most often I can fully wet it in 3 passes, one pass angled in towards the edges, to ensure good coverage on the corners, and one up the middle, not in that order. Most often I give it 2 more passes to leave the wet lacquer 'hanging' very fully wet, just prior to sagging (no sags!). Really it is not counting passes though, but following the wet film, watching the lacquer flow into glass as the fan passes over the surface. That is key to learning to get a good finish. If it is taking 5 passes to barely wet a side, that is not enough fluid flow, IMO. Of course gun settings, and spray technique have a big role in this. This is why I would not choose a touch up gun, or small tipped gun for spraying lacquer on most things, especially ukes. It will work, but not like a faster gun.

The problem with the Earlux sprayer is that it lacks the power to atomize finely enough to leave a nice smooth coat without orange peel. So you end up spraying more on and sanding more off, never quite sure how much lacquer is on the instrument when you're done. You increase you chances of success with the Earlux by reducing your mix up to 50% and adding up to 5% retarder as well.
I never cared for Behlens, especially after switching from McFaddens. It never seemed to dry as hard as it should and it is more sensitive to blushing than other lacquers I've used. I found my tone improved after switching to a harder lacquer. There are better choices IMO.
With my Fuji Q4 I use a 60/40 mix of lacquer/thinner with 4% retarder added @ 75 degrees F. I spray three coats on in a day within an hour of each other. Wet sand the next day and repeat with three more coats. The finish is very smooth and flat with very little leveling necessary. Let cure for 2-3 weeks before final finishing.
It may be bad practice but I never clean the gun between sessions and rarely will I clean it if I'm spraying the next day. Every year I take the apart and clean everything in lacquer thinner. I always wipe the gun down at the end of the day and blow back the tip as John suggested.
I buy brown kraft paper (Home depot) in 3' wide rolls. I hang it on my spray room wall like a window shade. It's the backdrop that I spray onto and squirt my tests shots on.

Chris_H said:

The lacquer gun I use with Cardinal (not that lacquer brands matter much when choosing tip size, just that I have a few different lacquer guns, for different lacquers) is an Accuspray HVLP Model 10, I believe (not turbine) with a #61 tip, which is 1.5mm, and a #807 air tip. It is set up on a pressure cup. It is my favorite gun ever for spraying lacquer, extremely friendly gun that just sprays glass all the time. I would not want a smaller fluid tip for lacquer. Not enough fluid flow means more passes to cover an area, which can translate to more texture in the finish. Say, for spraying the side of an uke, Most often I can fully wet it in 3 passes, one pass angled in towards the edges, and one up the middle. Most often I give it 2 more passes to leave the wet lacquer 'hanging' very fully wet, just prior to sagging (no sags!). If it is taking 5 passes to barely wet a side, that is not enough fluid flow, IMO. Of course gun settings, and spray technique have a big role in this. This is why I would not choose a touch up gun, or small tipped gun for spraying lacquer on most things, especially ukes. It will work, but not like a faster gun.

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I agree re the door jamb guns. I used to buy the $29 models on line or at the big improvement stores. Not only do they require constant refilling if you're spraying multiple ukes but you can't get a wide enough fan to wet the surfaces with a couple of passes.
BTW, of the many advantages I've found with HVLP systems is the ability to spray in tight spaces (such as the inside surfaces of a slotted head stock) with good, even coverage. I only use my compressed air system when shading with colored lacquer because it atomizes more finely. The HVLP also leaves less vapor in the air because of the larger particle size.

I also have a nice Graco turbine. It sprays almost everything depending on the fluid tip/nozzle. I do not care for it for lacquer, as I find the turbine hose to be kinda clunky. It does spray lacquer very well, but I like my Accuspray HVLP that runs on compressed air better. My spray booth works well, so the very slight additional overspray is not noticed. Any decent gun that is suited for lacquer should be able to be dialed back to spray in extremely tight spaces. And if it really needs to be tight, maneuverable, it goes on a pressure pot.

And on cleaning the gun, I open the cup only to fill it. I clean the cap before I use it, mostly, as my habit is to look at the finish for a second, set the gun down and walk off. I check the cap and the outside of the fluid nozzle for buildup before every spray session, and in the middle of, if it is a long session, like when production spraying. I am not afraid to leave the cup gun, or pot for weeks after a spray session. The gun gets a thorough cleaning when it starts to suffer. Sometimes I will put the air cap in a cup of thinner, but that leaves the delicate fluid tip unprotected, should it get bumped, which will ruin it. In theory I should probably clean the gun more often, but this is what works for me.

If I were spraying 4 ukes at a time, I would use a 2 qt pressure pot hooked up to whatever gun I liked( wouldn't work with gravity flow cup guns). Fill it maybe once, maybe twice and all 4 instruments are sprayed. With just the fluid hose instead of whatever type of cup, the gun is more fun to spray with, more ergonomic, especially with a turbine hose. Pressure pots are awesome. If the gun/ lacquer/ technique is all dialed in, there is effectively zero difference in film quality. Pressure pots are excellent tools. Also, they are super friendly with regards to cleanup, as there are less refills, less chance to contaminate or make a mess, and after finishing spraying, it can be left for weeks with no ill effect. Just plug in the air ( a pancake will run a pressure pot), turn the air off at the gun, flush the lines, turn the air back on, test the fan, and go. With anything but gloss lacquers, the flattening agents will settle in the lines, so that needs to be flushed before spraying again.

Chris_H said:

The lacquer gun I use with Cardinal (not that lacquer brands matter much when choosing tip size, just that I have a few different lacquer guns, for different lacquers) is an Accuspray HVLP Model 10, I believe (not turbine) with a #61 tip, which is 1.5mm, and a #807 air tip. It is set up on a pressure cup. It is my favorite gun ever for spraying lacquer, extremely friendly gun that just sprays glass all the time. I would not want a smaller fluid tip for lacquer. Not enough fluid flow means more passes to cover an area, which can translate to more texture in the finish. Say, for spraying the side of an uke, Most often I can fully wet it in 3 passes, one pass angled in towards the edges, to ensure good coverage on the corners, and one up the middle, not in that order. Most often I give it 2 more passes to leave the wet lacquer 'hanging' very fully wet, just prior to sagging (no sags!). Really it is not counting passes though, but following the wet film, watching the lacquer flow into glass as the fan passes over the surface. That is key to learning to get a good finish. If it is taking 5 passes to barely wet a side, that is not enough fluid flow, IMO. Of course gun settings, and spray technique have a big role in this. This is why I would not choose a touch up gun, or small tipped gun for spraying lacquer on most things, especially ukes. It will work, but not like a faster gun.

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I'll give the larger tip another try now that I've got my technique and mix down a little better but I'm sure the ratios may have to be adjusted for the larger tip. The thing is that without having the adjustable spray pattern you're just kinda stuck with what you have and before, the larger tip put way too much down at one time. You really had to kinda move fast and be careful

Can you not adjust the fluid tip down to control that? Also, part of the learning curve with lacquer, or spraying anything, is not pulling the trigger on a stationary gun. Getting intrinsic feel for this takes a little while. If you pull the trigger when stopped, over a workpiece, you will have a lump of lacquer, or should have anyway. I would guess that the fluid knob is going to be more important than the thinning ratio with a larger tip. It should work better for you. If it is really too big though, that is a different story.

Beau Hannam Ukuleles said:

What size spray tips do you guys use in your guns?? 0.08mm, 1mm??

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No idea. Its pretty easy to adapt spraying technique to the gun. For the last 4 or 5 guns I've just used with whatever it came with. As long as the gun's adjustments work well I'm pretty happy.

Chris_H said:

Can you not adjust the fluid tip down to control that? Also, part of the learning curve with lacquer, or spraying anything, is not pulling the trigger on a stationary gun. Getting intrinsic feel for this takes a little while. If you pull the trigger when stopped, over a workpiece, you will have a lump of lacquer, or should have anyway. I would guess that the fluid knob is going to be more important than the thinning ratio with a larger tip. It should work better for you. If it is really too big though, that is a different story.

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No adjustments, no fluid knob. The only adjustment is the horizontal or vertical spray pattern. The only way you can really change anything is with the tip and how fast you move across the work. That's why I'm looking at the Fuji and this thread has pretty much sold me. I just finished a dulcimer with shellac and I think the lacquer is WAY easier and faster. Just now I'm working on a french polish baritone that I wish was lacquer

Moore Bettah Ukuleles said:

I never cared for Behlens, especially after switching from McFaddens. It never seemed to dry as hard as it should and it is more sensitive to blushing than other lacquers I've used. I found my tone improved after switching to a harder lacquer. There are better choices IMO.

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I used to use Fabulon lacquer floor finish. It built up fast, dried hard, sprayed nicely. It took me years to discover that it tended to cold check badly over time. Never had a problem with Behlen's lacquer, other than paying for it. I actually like Parks lacquer. Ace Hardware used to order it for me for $28 a gallon. Its been awhile since I bought any.

A lot of furniture and floor lacquers like Maclac will weather check, especially if it's too thick. Keeping the finish to 3 or 4 mils you should be able to avoid most cold checking.
I'm sure it eventually cured hard but it always seemed to me that Behlens always sanded out kind of soft, even after letting it hang for 3 or 4 weeks.

Chuck, as I recall, you used to favor McFadden: what are you using these days?