An upholsterer associate brought in a dozen spindle-back rocking chairs to finish for one of his clients. We almost always do case goods. We've gotten the prep, color, and seal/body coats done. The issue we are having is due to our lack of experience with this type of spraying. The main problem is overspray falling onto the seat which doesn't fully melt-in, leaving a coarse finish. Our approach has been the usual vertical first, then horizontal from top down. By the time we spray all the vertical spindles, the pre-cat has already started to flash-off where we started and the overspray on the seat is fairly dry. Are we making a mistake in trying to spray the whole chair in one shot? Perhaps we should do everything except the seat, scuff the overspray off when dry and spray the seat as a separate run. Any suggestions would be most appreciated.
From contributor A:
I will preface this by saying I am not a pro at spraying chairs. I spray them upside down to start with, spraying the bottom of seat and legs, and then spray the underside of the back rest and spindles. Then I flip the chair over and finish the legs and spindles, then finish with the seat last - little or no overspray on seat. Not sure if that makes any sense or not, but it has worked for me. I will check back later for better ideas myself.
It helps to add some retarder to your finish. I notice that when I spray unreduced coatings through the Kremlin Airmix, an air-assisted airless, when I go back and spot spray an already wet surface, I get invisible melt-in. When I do the same with my pressure feed or gravity guns then I do see the fresh spray even though the two fresh finishes are still wet. This has to be from the almost no overspray from the Kremlin. Overspray is more cured than the wet coating that it lands on and the result is varying degrees of roughness, and that's what's happening to you.
Underside of chair
Underside of rungs and stretchers
Inside of legs
In my case, it's not easy. It's rigorous. And there can be runs and drips. I hate those. I also hate rough spray. There are so many operations in factories that it would be so juicy to set up a camcorder and just let it roll for maybe thirty minutes. To videotape the spraying of chairs is just one juicy pipedream. Isn't it both funny and curious that there are so many spray operators who work in these factories, so many line workers and not one of them ever write into any of these online forums. We never hear from these invisible, mythical employees. Chairs are not the most challenging spray objects, but close. Stools are the most challenging.
Place chair upside down on a turntable stand. Spray from outside in and the top down so you are putting fresh lacquer over any overspray. Outside of legs and rungs first; bottoms of arms if applicable; insides next, spraying out, so no overspray lands on finished parts; chair bottom last. Flip it upright and start with the back, spin it and, starting at the top, do the outsides of the legs again, the front of the back, the arms and the seat. I wouldnít thin the lacquer Ė you donít want runs and you do have to go over places if you see dry spray. The whole process takes about 60 seconds and you have to move very fast indeed, so it helps to practice your moves in advance.
It seems like a lot of steps until you get the hang of it but in reality youíre just turning the chair four times on the turntable. Add some retarder to your material and donít be afraid to overlap some of your passes. Years ago the company I was working for contracted with a company to stain and seal and top coat 1000 maple chairs. The owner of the company set up three of us with pressure pots and turntables and we finished the entire job in a week. I might add that we had a wall booth that made this type of project quite feasible.
The next most challenging time I had was with a lamp table that had a fixed lower finished shelf. No matter what I did, there was overspray or dryspray somewhere. The amazing thing about the large companies that manufacture retail furniture is that the casegoods are sprayed assembled. That differs from cabinet finishing where we do everything possible to spray flatline.
Comment from contributor N:
We make and finish about 800 very high quality chairs per year in our 4 person shop. Finishing can be very quick or it can easily be tedious and stretch into hours. It's the final coat (out of two) which makes or breaks it. First use an AA setup, we use Kremlin. Secondly use a lacquer which will do what you want. We use Becker-Acroma Fawcett. First coat full strength, then start on the second coat reduced 10%. After flash off feel the corners under the legs for overspray. Add thinner or retarder, try again, and check for overspray. You know you've added enough when there is no more overspray.