The Fine Points of Spraying Dye Stain

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Pros supply mixing and application tips. April 14, 2005

Question
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.

Forum Responses
(Finishing Forum)
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.



From contributor B:

We use dye stains almost exclusively. If you are spraying on bare wood, it’s all about the dye and the technique. The dye can be concentrated for your need or thinned down for your needs. Similarly, dye can be fogged on to sit on top of the wood or soaked on to penetrate into the wood. We never use toners- it just doesn’t make sense to do that as I am spraying from drum quantities. I’m a bit spoiled though - my wood selection is good, and things are sanded nice, which goes a long way to make an even color.
You have much more finesse when you spray from a cup gun compared to a pressure pot. Example: squeeze the trigger a little bit, and a little bit comes out. Squeeze it a lot and a lot comes out. Pressure pots keep the dye under pressure, so as soon as you pull the trigger, a little bit or not, it comes flying out.


From contributor C:
I use a cheap gravity gun with a small tip. It works fine and price is right.


From contributor D:
The number one thing you must do is make full samples of your finishing schedule. This means from start all the way to the last coat you will apply to your job. Dye stains vary so much in type, potency and the way they actually color the wood that I think it's only fair to point out you will have to shop around for ones that you feel comfortable using. There are dyes that are spray-no-wipe formulations formulated specifically for this application method. Keep in mind that spraying anything - coatings, toners and stains - to obtain uniformity takes a long time to get the hang of. The reason for this is because turbulence caused by the pressurized air atomizing your material disrupts fan patterns, which in effect leads to a mottled look to these coatings. Like I said, adding this and dropping pressure there plus not having some cabinets fully assembled all add up to a great looking job or not.

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!



From contributor B:
I would recommend a Devilbis JGA siphon feed gun.


From contributor E:
While I don't have the years of experience of many here, this is what I do. I don't like mixing the dye in with the final finish since I've found it tends to reduce the optical clarity of the finish. Most of what I use in the way of dyes are NGR types so I can't comment on others.

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.



From contributor F:
I was in your position just a few months ago. I was a little apprehensive about a new technique, but I had to find a better way to get the look I wanted. I used just plain wiping stains (SW) but got tired of ragging everything down and the heavy dark endgrains and edge grain. I formulated a spray stain per SW specs and found the technique fast and fairly uniform. I have since worked in a toner application which seems to help even the color and darken as well when I need that effect. I started with a JGA gun, but since have switched to a VTX with a 2-1/2 quart pot. This setup has been night and day compared to the JGA.


From contributor H:
I have good results using the technique pretty much as contributor A said. I like to seal wood first. That keeps the dye from being absorbed into any of the wood’s fibers and avoids hot spots of color. Sand and then mix your dye into a solution of 50% finish and 50% thinner. This gives you enough finish to encapsulate the particles of dye and act as a binder. The finish is reduced enough so that you can make multiple passes to build your color, which gives you good control of the color without the risk of adding too much film thickness, which could lead to cracking down the road. Shoot it at 25-30 psi and turn down the material flow at the gun. You don't want to flood the surface. Spray light wet coats. Let each coat flash a few seconds before applying the next coat to avoid floating and blowing around the dye. For light colors, I aim for making 3 to 4 passes which give me personally good control in a reasonable amount of time, so add dye in an amount to get to a rate that fits your requirements - complex pieces should use less dye and more passes again for better color control. Avoid adding too much dye as that reduces your control and every dye and finish has a load limit so contact your manufacturer for their specific recommendations - some dyes are less concentrated than others.

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.



From the original questioner:
I think I will stick to my Devilbis cup gun since I don't own a 2 or 2-1/2 qt. pot, and the 2 gallon pressure pot may push too much material. I understand about the air disturbance in inside corners. I am lucky that these cabinets are frameless and there are only 2 finished ends on 2 wall cabinets. All the rest have separate panels which can be sprayed flat like the doors. I will spray a natural finish on the inside of the cabinets.

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.