- Spraying Dye Stains Smoothly

Achieving an even, streak-free finish. June 4, 2004

Question
(Finishing Forum)
I started using concentrated dyes to make a spray stain. I use the stain to finish cabinets and doors. I am very pleased with the look of the dye stains compared to what I had been using.

My only problem is that I can't seem to get the stain sprayed even enough. A lot of my doors have darker shading going up and down, I guess from overlapping with my spray gun. It seems impossible to get it even without overlapping at least a bit.

Does anyone have suggestions for spraying stain to achieve an even finish? I am using an Astro gun with a 1.3mm tip. I turn my fluid output way down, and my pressure pretty low.

Forum Responses
From contributor R:
Have you reduced the dyes? Many dye stains benefit from reduction with the appropriate reducer. You will need to make more passes with the gun, but you will have much better control. Every manufacturer has a different system and thus a different reducer, but in general, spray the dye at 25-30 psi and turn down the material on the gun so the dye comes out and dries almost instantly on the wood. The speed that you move and the distance of the gun from the wood will also be of influence. In general, you don't want the dye to puddle on the surface and be blown apart by the atomizing air.



From contributor O:
I am by no means an expert, but from what I have read on this topic, and what I have experienced myself, I try to lay down a very light coat, getting the color I want in 4-6 passes with the dye. This allows me to go over several times and get even coverage, avoiding the stripes that you speak of.


From the original questioner:

My most recent color is a mix of 3 tablespoons of brown concentrate and 1 tsp of yellow, to 16 oz. of lacquer thinner.

Are you suggesting that if I mix the same colors in maybe 32 oz. of thinner I will get the same color after more passes, but a more even color?



From contributor S:
You're on the right track now. It's very hard to give someone an exact formula because each color and its strength will differ from manufacturer to manufacturer.

If you're seeing color in your first pass, it's too strong, so thin it out. I would rather see a tint of color in the third pass. This will eliminate the striping. Test the stain's color strength on some old newspaper or cardboard.



From contributor J:
Yes, you can get to the final color you desire by several sprays with less pigments, as close as possible to spraying it at once, but I think it would be much more beautiful to do it by several coats, because it will have more deepness and be closer to a factory finish.


From contributor R:
Not being familiar with this system, I suggest you adjust your technique/material/air first and only then, if you still can't control the dye, add more reducer. There is a point where the reducer can start to get in your way by keeping the surface wet longer and making you wait longer between passes so that you don't blow the dye apart.


From contributor P:
Try "fogging" the dye on more than spraying wet passes like you would with a topcoat. Use a wide fan with lower fluid flow and overlap each pass enough to wet the wood evenly (don't worry if the spray pattern is center weighted; just adjust to overlap to compensate). Spray the dye just wet so that it doesn't pool or puddle but does wet out the wood fibers well.

Keep the air pressure as low as you can and still get good atomization. The lower air pressure will help get the dye into the corners as you spray.

Your mixture sounds pretty weak; you should be able to avoid stripes by adjusting your spray technique (fogging).



From contributor M:
I hope that you don't mind me jumping in here on your post, but I too am getting better at spraying dyes.

I am still having problems getting the dye to "fog" into corners/right angles. I am using a Binks 2001 with pressure pot. I have turned down both the air and fluid. Are you still using a wide pattern when you hit these areas?



From contributor R:
Try turning your pot pressure way down, just enough to get the stain out. Adjust fan to a circular spray pattern and again cut back material flow so that only a small amount of stain comes out and dries very quickly on the wood. You might (most likely) find that a tank setup is too much for this application. Try using a siphon or gravity feed cup gun. For problematic areas a little touch-up gun or air brush might be needed.

When you spray inside corners, don't try to spray at a 45 degree angle into the corner. Shoot parallel to the face of each intersecting plane. So, for example, you will shoot the side up to the corner and then the top up to the corner. The instance where a top, bottom and back all intersect is very tough. Leave the back off to get best results.



From contributor S:
Contributor M, if you thin out the dye so it takes a few passes to see color, and you keep the gun moving and allow the stain to dry before going over it, then it should work.


From contributor J:
These are two samples I did today at work. The one on the left is done by spraying a tinted (I think that what it is called) base coat. I added a concentrated stain that can be thinned in water or solvent, and I sprayed three base coats and over all a topcoat.
In the second piece I wiped the same stain, Green Walnut, that was thinned in water and then base coated and then top coated.

Notice the difference in the deepness and smoothness of the color. To get the same color it depends on sampling and how good you can get.




From contributor M:
Contributor R, I think in the past you have recommended a HVLP gun to prevent a vortex. I will have to try the new angle, but let me make sure that I understand. Let's use a drawer box for an example. I should spray perpendicular to the bottom, with the tip of the fan hitting the corner (or overlapping slightly?). Then I spray perpendicular to the side. Are we still using a starved circular pattern? I have used a gravity HVLP with lower pressures since I read your last post, but maybe I still had too much fluid.

Contributor S, I know that you have had a great deal of experience with conventional guns. Are you saying that when I spray dye I should use a thinned version for the corners, or use the same solution for everything? When I have used the same solution for both, I still get low coverage in the 90's.



From contributor S:
I have been using HVLP guns for over ten years. I use this same method for both types of spray guns.


From contributor F:
I spray a lot of right angles and inside corners with the lamps I make. I turn the fan to a circle and close the needle to about 1/16th open (barely open). I turn the atomizing air down so it is just able to atomize the stain (in my case, toner). My pattern is just about 1/4" to 3/8" in diameter. (For cabs and drawers, 1/2" to 1" would probably be more appropriate.) I aim the gun into the corners and spray them with one or two light coats. Then I come back and spray the entire lamp with color without regard to the inside corners/right angles and everything comes out even. I use a remote 2qt pot but don't adjust the pressure to the fluid. That stays at 5-7psi.


From the original questioner:
I want to cover one more aspect to spraying stains on cabinet doors. I don't know if my spray technique could also have a factor in me getting vertical lines.

I have a little lazy susan that I set my door on. I shoot the edges first, then I shoot from the left top corner of the door to the bottom and continue across the door. I then spin the door 180 degrees and hit it again.

I noticed in a video that someone here recommended to me that they sprayed the door vertically and then hit it horizontally. Is this the recommended procedure?



From contributor M:
Yes - North/South passes, then East/West. Or, E/W, then N/S. Compass is optional ;) I have found that doing this 4 to 6 times gives me the consistency that I am looking for. Just make sure your dye is thinned appropriately for this many passes.


From contributor P:
The 90 degree rotation is called "box coating." I use it sometimes when applying topcoats but not when spraying colors (dyes, stains, or toners).

When spraying colors, I like to spray with the grain (the panel on a door; I don't spray the rails/stiles separately except for the edges). If there is any slight striping, spraying across grain shows it a lot more than with the grain.

You're getting stripes because you're not wetting the wood evenly with the dye. Do some test spraying on scrap ply or even cardboard. Watch how wide the wet area is as you spray a couple passes. The fluid will be a little heavier in the middle of the spray pattern and stay wetter longer than the edges. That's the portion of the spray pattern that you have to meet when you spray the next pass.

For example, if you have the fan width set at 8" and spray a pass, you'll see a stripe in the middle of the pass 4" - 6" wide that gets wetter than the edges. When you spray the second pass, overlap the pattern enough to meet the previous wet stripe with the new wet stripe.

It takes a little practice, but you will work out the technique. Fan width, fluid flow, atomization air pressure, and hand speed all contribute to even wetting or spraying stripes.



From contributor S:

You also need to hold the gun at a steady distance from the work. Moving the gun in and out will not give you a uniform color.


From contributor W:
I can confirm P's and S's observations.

I just wanted to add that with dye stains I mix my colors so that I can develop the full color with just one pass, wetting the wood enough so that it will flow together evenly, but soaks in or flashes off within 5 to 10 seconds. Too dry a spray looks bad and can give you stripes because it doesn't flow together, and too wet a coat makes you have to wipe it to prevent drips and bleed back, and gives an appearance that I don't usually want.

Multiple passes of dye stains often soak the wood with solvents that later bleed back out of the pores and ruin the appearance, so if I goof up and have to make multiple passes, I allow plenty of drying time between coats.

This is the exact opposite of how I handle toners, which go down in very thin layers of highly diluted material.

Even with pigmented stains, I try to apply them so that wiping is needed only to bring up the grain. This is the best way I know to avoid blotching.

Any extra time these techniques require per pass is more than compensated for by the time not used in extra passes, or in wiping.



From contributor S:
The trouble I find with pigmented stains is that no matter how you apply them, unless they are wiped dry, you don't know when you will end up with patches of dried pigments. There will be certain areas in the woods that will not suck in the stain, and the pigments will lay on top after the solvents have evaporated.

That is why many finishers say pigments block out the woods like a paint, because pigments lay on the surface of the woods. I personally like all kinds of pigmented mediums, and I know it's the finishers who create the painted look and not the pigmented colorants.



From contributor H:
I'm with contributor P's and W's approach and contributor S is on target about the importance of good gun control.

No matter how much or how little you thin, it is very difficult not to get some degree of striping when using a sprayed ngr type dye application as the only coloring step.

To cure this, I nearly always follow a sprayed dye application with a wiping stain. This always evens out any inconsistencies of the sprayed dye and also defines the figure of the grain. Sealing the dye and then glazing achieves the same improvement, if not better. Sprayed solvent dye by itself is a rather cold look.

I also spray my wiping stains and I do want to thank contributor W for the tip about not spraying them so heavy. I was trained to always flood them on and I guess I never really questioned to do otherwise. So I took the suggestion and I'm finding it really does help control blotching on some woods if I don't spray the stain so heavily, not to mention I'm saving time, stain, and wipes.

Just had to deal with some new alder cabinets and the technique worked great. Alder blotches like crazy when you flood the stain on.



From contributor R:
In the video, I sprayed the door, rotating 90 degrees, because that is the only way to get into all of the nooks and crannies of a raised panel door. On flat stock I also tend to spray with the grain, but with items that have detail, you have to do what you have to do to get the stain where you need it. When you look at the completed door, you don't see any stripes. Flat panels or raised panel doors you can apply dye without stripes. It's all in your technique.


The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:
I spray dye stains quite regularly on veneers used on cabinetry for aviation purposes. Too many passes leave a buildup of stain. Allow to dry to about 95%, then even out with a lint-free rag or a stippling brush. This gives more even color and also allows different grain features to be highlighted.



Comment from contributor B:
When we talk about technique to someone that has none it can leave them scratching. Try tilting the gun tip up about 30 degrees and stand off the surface a bit when fogging. You will have far more control with that reduced air/product/and dilution you have created. Also, keep your hand moving - do not stop over the work surface. I also use a turn table I made from a barber’s chair base. It goes up and down as needed and spins to do those inside and outside edges without color build up.