I’m having problems spraying Sher-Wood CAB lacquer on 3/4″ cherry plywood.
I’m using an HVLP system–1.4 mm tip. I’m spraying the recommended sanding sealer under the lacquer. I’ve even attempted to reduce at varying percentages. I’ve attempted to spray in a heated shop, a cool shop, morning, night, etc. Still no luck.
My main problems is “orange peel”–ranging from really, really bad to just barely perceptible. I’ve tried ever mixture with air pressure and fluid adjustment I can think of.
Kind of at my wits end right now.
Replies
Rob,
A few questions:
What is the temp range you are trying to spray in? What exactly are you using for thinner? What brand of gun are you using? Are you thinning the sealer? What sealer are you using? T67F3?
The 1.4 mm tip is about right for this product. Sounds like you may need a little more thinner or a different (slower) thinner, but I would like to know how much you are thinning the product. I always measure a full quart of material and then measure the amount of thinner I am using so I know where to start from.
Lee
Temp range has been anywhere from 65 to 80 degrees. Thinner is basic medium drying lacquer thinner. Gun is basic HVLP gravity fed--nothing all that expensive. Vaper brand name--$100 I think it was.
Did not thin sealer. Yes, I did use T67F3.
As for the quality of gun. I have never had a problem with this gun--even though it is not top of the line. I do not finish enough to invest in a Kremlin, etc. Also, an interesting tidbit here. I have gotten good results on the solid cherry itself, and I have gotten good results on the 1/4" cherry ply. This is why I am my wits end.
Thinning has been an adventure from no thinner, 10%, 30%, all the way up to 50%. I stopped there because I was just spraying money into the air then.
Rob,
Sounds like Rich has you going strong. Good luck!
Lee
What is the manufacturer's recommended tip size for this product for HVLP? Looking at the Product Data Sheet I don't see a recommendation for HVLP. For "Airless" and "Air Assisted Airless" they recommend much smaller tip sizes than what you are using.
Yea, I did read the data sheet. But when I started getting good results on the solid cherry and other types of wood I was experimenting with, I kept going.
Now I'm sitting with nicely lacquered doors and a cabinet that just won't cooperate. I can't afford to go purchase a whole system for this cabinet.
Robi,It is strange that you've had no problems on solid wood and on 1/4" ply, only on 3/4" ply.I have used Sherwood CAB Acrylic lacquer and its companion high-solids sanding sealer for years and I think it's great. I don't use any other brand of lacquer. I've used all manner of spray equipment from a very cheap Home Depot standard high pressure gun with suction feed to gravity feed Grizzly guns - both HVLP and LVLP. After a few adjustments to my own "technique" with different guns, the stuff just works.I have a standard high-pressure compressor - Craftsman 1.5 HP, 125 PSI (with variable pressure valve), 3 Gallon. I was walking through my Sears store one day and they were clearing them out at $99. Deal. At first I had doubts about its ability to drive an HVLP gun, but there's never been a problem.So you see, I don't have fancy gear. (I believe spray cans do the job if that's what one wants to use!) I use 1.3 and 1.4 mm tips (the ones that came with the guns). I have never diluted the lacquer or the sealer. And the only problem I've ever had was blooming when I sprayed on a very humid morning. That all tells me that parameters can be adjusted as necessary to prevailing conditions to spray the standard mixture pretty much without any need for modification.So I don't believe that equipment makes a difference, it's technique and adequate adjustment of the available controls on the gun and compressor.Orange peel comes from improper viscosity or pressure, gun too close to the work, high ambient shop temperature, improper feed flow, improper pressure to the gun or a combination of these factors. In my case it has ALWAYS been a matter of getting too close so that the air stream physically disturbs the wet film. (A VERY tiny orange peel texture is a normal result of lacquer application. Look at even the finest cars. The last application is always left un-rubbed, and although the finish looks like sheer perfection, if you look close you can see it. And those boys use the very best equipment and have exquisite control of the viscosity and temperature of their very expensive acrylic lacquers.)Since you've had good results on part of the work, it's obvious that your equipment and material CAN do the job. Maybe with the cabinets themselves, however they're positioned for spraying, you're not in the proper or comfortable "spraying stance" with the light in the shop positioned "just so" that you can constantly see the surface right where the film is being laid down and wetting the wood.Rich
Thanks Rich,
I just came in from the shop--and experimenting some more. I did receive better results this time from doing exactly what you said. I began by starting where I left off and then changing one thing at a time.
One of the things I changed was line pressure. The regulator on my gun was set at 8-9 lbs. but the regulator on my compressor was set at 90 lbs. So I cranked the compressor down to 40 lb. and things began to change. The gun held the 8-9 lb. setting better and all I did was adjust the mixture a little bit.
The first coat went on good and the "orange peel" did smooth out. So, it was my own fault of not resetting the compressor after using the nail guns. Maybe it was when I was yelling at the dogs for wrestling in the shop. :)
Thanks again.
Good luck!Rich
Rob:
Rich is a great source and has been of great help to me, both directly and indirectly.
I almost exclusively use the Sher-Wood lacquer. I spray outside under a tent in all sorts of temperature and humidity levels. I live on the Gulf coast.
Under these conditions, I found the best results with a 10% to 15% dilution with lacquer thinner and 3% addition of Butyl Cellusolve. This was recommended to me by the S-W technical support. I have not had a problem since using this mix. I use a LVLP gun by Iwata.
I don't know whether this would work for you.
Hastings
This forum post is now archived. Commenting has been disabled