Getting Even Coverage when Spraying Dye

Advice on how to prevent a dye coat from getting a mottled appearance. June 4, 2012

I'm trying to spray a base coat of dye on some maple and can't seem to get it on evenly. My fluid is set way down and I'm trying to fog it on, but it seems to go on mottled. I'm using a Devilbiss Transtech with a 1.2mm cap/needle and 20 psi. In the picture I went over it about 10 times. Any suggestions?

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Forum Responses
(Finishing Forum)
From contributor A:
Mottling is often caused by using too much air pressure and/or moving too fast. Are you thinning your dye or are you spraying it on full strength? It helps to reduce it and slowly build up to your colour.

To blend in the mottled areas, you might want to try using a very diluted mixture and just lightly misting over the lighter areas until it blends. Dial the fan back to about 1 or 2 inches. If that doesn't work, I hope you like sanding...

From contributor P:
I use waterbased dye, and have better luck flooding it on wet and wiping it off. I get color control via dilution versus trying to build it up.

From contributor R:

I would suggest using an aniline dye also, but instead of using water, use acetone, alcohol or naphtha, as they don't raise grain as much and dry much more rapidly. Acetone goes off immediately and use dilute solutions of dye and build color. Also I use a touchup gun with a tighter tip, as it is essentially solvent you are spraying.

From contributor M:
I spray Mohawk alcohol based dyes, and I spray full strength. I prefer to use more air and less fluid and spray slower and just mist it on. When I've tried more fluid and less air, I always seem to get dark spots.

From the original questioner:
Thanks. I'll have to give those methods a try. Moving slower makes a lot of sense.

From contributor D:
Yes, don't fog it on. Thin out the dye so it wets the wood more. I have seen a lot of dye sprayed just like in your picture. You have to practice on scrap first.

From contributor F:
Your cap/needle is too large. Use a .75 cap and needle an dial down your air flow at the gun. I also agree with using alcohol instead of water with acetone or lacquer thinner.

From the original questioner:
I don't have a smaller tip, but I will get one and give it a go. Thankfully, I needed to go way darker so I was able to mildly improve the dye uniformity, then even it out with stain and toners.

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From contributor D:
That looks nice now! Good job.