I have read many threads about applying dye stains and I see that it's best to have plenty of atomization and low air pressure. I have a maple kitchen to finish with a light honey color and ordered a dye stain to match a sample provided by the architect. I hope to accomplish this color without blotching by spraying the dye stain and then finishing with pre-cat lacquer.
My question is, should I use a cup gun or the Binks pressure pot? I would think the cup gun would do the job better but I want to ask the experts as I have never used dye stain before and this is an expensive job.
From contributor A:
I am not one of the experts. But I will answer from experience. First, you will get better results if you mix the dye stain into your finish so that you are toning more than you are dye staining. You still get some soaking into the wood but it is more controlled, thanks to the precat as a binder.
This is what is done at a cabinet shop where I do some spraying. You need to lightly scuff between coats but that is no big deal. Just remember that when you are scuffing you are also removing color, however small, to some degree. If you do not go more than 2 oz per quart of mixed finish then you will have a blend that should be able to get the job done without striping as you spray.
Your gravity gun will probably yield more consistent results than a cup gun. And the cup gun will probably be better than the remote pot unless your remote pot is outfitted with the expensive fittings. I have a pressure regulator from Binks which is maybe $90. It dials in from 0 - 15 psi. It is only one this accurate which you want to use for your pressure pot if you are toning. That is your best bet on even pressure settings which remain true unless you do some knob turning on the regulator yourself. The less expensive regulators are less accurate. I have a pressure gauge which is 0 - 30 psi for that regulator.
When toning like this, your material is nearly water-thin. Use the appropriate needle/nozzle and air cap to accommodate your thin finish. Several passes which overlap two thirds ought to get you there with no striping. And you need good rack lighting - lighting at an extreme angle so that you can see the material you are laying down.
If you are spraying in such a way that your material pools then you are spraying too heavy. You want a fan that will flash in less than 7 seconds. Do not dust on the toner and do not spray heavy as it will mottle. In between those extremes is a good way to go.
To answer your question - the light honey color should not be very difficult but I would suggest that you break up this color to match your sample. Spray with a pressurized 2-1/2 quart cup gun set-up (cup gun you'll be filling all the time and pressure pot will use too much material getting it through the lines). Spray a reduced dye stain onto your wood - seal, sand, tack then topcoat. Using a solvent based dye in same color match tone 1-2 passes with this material - 50% solvent, 20-30% dye (test for % needed) and fill with topcoat to reduce bounce back from turbulence. The success of an even color all depends on your skill at dialing your equipment in, surface prep, formulations and most importantly your steady even spray technique and procedures applying it to the work. For light colors similar to the wood color you might be successful with one application on the raw wood. Samples!
I use the spray/wipe method. Spraying with one hand and wiping with the other. This helps me get an even coat. However you've got to be quick. I've done this also with a helper following behind me doing the wiping.
I will often pre-condition the wood with a 1/2 to 1 lb cut of shellac to help with blotchiness. Let it dry. Seal with 1 lb shellac - this helps prevent bleed back of the dye into the finish. Then start with the clears.
After your last pass flashes you can topcoat. If you allow too much time after your last pass, wait, as pointed out. Scuff carefully with a Scotchbrite pad and then recoat - be aware that you are scuffing a color coat. Be careful on vertical surfaces as a run will cause the color to sink to the bottom of the run and be a pain to fix. I really don't recommend toners for dark colors as you have to use too much dye and too many passes. You risk adhesion and cracking issues. Personally I prefer a siphon or gravity feed gun rather than a pressure feed system for shooting toners, but if you use a tank, a fine tip and an agitator will help with consistency.
There are other techniques and styles of getting similar results. You have the tools - you decide which work best for your application. As always, SAMPLES.
The dye that is being custom mixed is ILVU or something like that, and they will already have it thinned with acetone and ready to spray. I am not confident enough in my abilities to try the toning route - maybe if I need to touch up a door here or there afterwards, but not enough to do the whole job - maybe another job that is smaller. I will be making samples.