Spraying Stain Into Box Corners
Advice on spray and wiping techniques for even coverage on box interiors. August 17, 2009
Question
I'm in a pickle. A large multi section entertainment cabinet, SA mahogany plus Sapeli veneer. Using Solarlux thinned 50% - two coats, gravity HVLP gun 1.0 tip. Haven't sprayed in a long time and it's a new gun. To get experience I sprayed the easier parts first, with some unevenness, but got better. I get to the first box "unit" (three boxes with backs one without, plus face frames). I found no matter what gun adjustments or technique leaves a bare strip in all 90*intersections, even the one without its back.
Now I have a bare strip with dark border lines as a result of trying to force the stain in. I've read all the archives and tried all the spraying suggestions and am convinced I will have to wipe this on (even an airbrush behaves the same). Here is my dilemma; how do I evenly wipe on Solarlux on such a large piece with intersections/grain changes - even with max retarder no hope of keeping it wet long enough. How do I make this look like what I have already sprayed. And of course how do I fix my striped box.
Forum Responses
(Finishing Forum)
From contributor G:
I'm sure you've tried it, keep the pressure as low as possible to get into corners.
From Gene Wengert, forum technical advisor:
This probably does not apply to your situation, but perhaps to others. If a piece is finished and then is allowed to dry a bit (low RH in the room or using a finishing oven), the wood will shrink and may expose un-stained wood, giving a white line.
From contributor J:
Thin the dye out more, you will have to do more coats but makes it more forgiving and easier to touch up when you do get a streak or shadow. Of course as others have stated, keep your air pressure as low as possible. Also, and this is just my personal preference, I would use a gun with a bigger tip. I know a lot of people will recommend a small tip for dyes, but I could never find a use for anything smaller than a 1.4 myself. I always felt it's easier to turn down a gun that sprays heavy than to turn up a gun that sprays light.
From contributor R:
On the box you have already sprayed the stain on, put on a pair of good rubber gloves and wet a rag in acetone. Wipe the entire cabinet with acetone - this will even out the stain and get into your corners. Now you can spray a light coat of stain over top of the wiped areas to get your color and the corners will be fine. This is just a lightly sprayed coat like a shading. I usually wipe the insides of boxes this way and spray only on the easier outside areas. It is dark enough in the box that you can't tell. On a new box just spray your stain thinned about 25% all over and wipe with acetone. Shade on some full strength to get your color. Sounds like a lot to do but it goes really fast and there is no inside corner problems. (I usually use a water based Lockwood dye so I can just spray wet and wipe which is easier).
From the original questioner:
Thanks for the suggestions. I built sample boxes to experiment. I used contributor R's suggestion to wipe down with solvent (lacquer thinner) to even out the stripes and corners - mostly a success. I still would like to wipe on the Solarlux to complete the rest of the project, what can I add to slow it down for use on large boxes? I have some SW K-27 retarder lacquer thinner is that compatible?
From contributor O:
Why don’t you mix an oil stain to match your dye stain and wipe everything down with it right after you spray your dye stain? It will even everything out with no problems. Say you get a dye stain from Mohawk (just an example) go ahead and get the same thing in an oil based stain or mix your own color to match the dye stain. This is done all the time and beats the bees knees out of wiping everything with thinners or other types of solvents.
From contributor P:
Behlen sells a Solar-Lux retarder. I've used it, and it does help with the open time. You still have to be strategic when applying it. You can't spray a giant piece and expect it stay workable. Try working with the spray gun in one hand and your wiping rag in the other. Like contributor R, I'm a big fan of the Lockwood WB dyes. NGR’s are too unforgiving for my taste.
From contributor E:
Try exercising proper gun angles when shooting into corners. You never spray directly into the corner, instead you spray with your gun at a 90 degree angle to your surface, and spray the corner as you would spray two flat surfaces. Do not angle the gun into the corner, as it will cause wind vortices that prohibit the stain from hitting the inner corners. Your pressure should be so low that it almost causes speckles from the large droplet size, as once the sealer hits the stain, it should blend it. Pressure and proper gun angling are vital to dye stains. Don’t be scared to take about five minutes and several scrap pieces until you get the perfect pressure/atomization.
