Whether to Seal Before Spraying Dyes

Do dye sprays require pre-sealing the wood? Depends on the intended look. April 30, 2006

What are pros and cons on spraying NGRs or dyes on raw wood versus spraying on sealed wood? If sealed, should the wood be with a wash coat or full sealer coat and scuff sanded? Does anyone have any comments?

Forum Responses
(Finishing Forum)
From contributor A:
There is an advantage to spraying the dye on the raw wood, as you have color in the wood. This technique requires some practice. Spraying over a barrier of a wash coat, glue sizing, clear base, or even boiled linseed oil the wood will still be raw, and subjected to scratches and nicks showing through the finish.

From contributor B:
If you are new to spraying dye it is always best to cut them when spraying raw wood. Also, the dye must be sprayed as a toner if you are going over a sealed piece. The dye has no binder. One thing a lot of people do when starting out with dyes is mix them: 1/3, 1/3, 1/3. Use one part dye, one part sealer or top coat, and one part reducer, usually Acetone, lacquer thinner or Methanol. This is a safe way to go over raw wood. You can go heavier with the dye if needed. Then you can go right over that with a wiping stain to get good depth in your finish.

I usually dye the raw wood first either straight or cut depending on the color I'm going for. If it's a softer wood I will seal and then go with a wiping stain. If it a harder wood, I will put the wiping stain right on top of the dye then seal and topcoat.

From the original questioner:
I was trying to get other experiences or better procedures as to whether to seal first with either a wash coat, full sealer coat or no coat (raw wood), before dye stain application.

From contributor A:
This is not rocket science, it just takes some practice. I suggest that you first thin out the dye, and then hold the gun at a distance away from the sample, some paper, or cardboard. Pass the gun, and slow bring the gun closer until the mist hits surface, you donít want to flood the dye, just keep moving the gun and allow the dye to dry before you pass over it again. As the color was reduced, it will be up to you to slowly build the color. It takes a uniform amount of passes to achieve the targeted color.

Remember, you will only see the true color of the dye after you have applied your clear coats. Don't try to get the color right away - you need to keep moving the gun making uniform passes. There is a learning curve to this technique - you need to learn to do it yourself, it will take some practice.

From the original questioner:
I'm not asking how to spray dyes but what to spray dyes on top of. What is the better one to do - spray on top of sealed surface or spray on top of raw wood? I know about dyes and concentrations and best guns to use and also a special technique, but wanted to get some opinions, ideas, experiences, etc. as to what others may have run into. As was pointed out the density of wood does have a lot in making decision which way to go. Are there any other factors which would be major in coming to decision of sealed or raw?

From contributor A:
You need to decide for yourself on what to do when you run into different species or porosity of the woods. With each piece that you work on, you may find the wood may not be exactly the same. Itís for you to blend in these pieces of wood. This may take another color stain, a glaze, or a shading stain to make the final adjustments. Every finisher has to do this same thing sometimes, if he wants all of his pieces to look the same. As I mentioned earlier, the sealer will prevent blotching because the stain will lay on the sealer and not the wood. If you know how to control the dye, I personally feel that the dye looks better directly on the wood than it does on the sealer, but thatís another question. I'm sure, you will find your way - we all do in the end.

From the original questioner:
To contributor A: I appreciate your remarks to the posting, but I'm really not lost. I was just asking for opinions. You stated yours. It's ok to spray dye on sealed wood, but it's also ok to spray on raw wood (which you like best). Like you said, it's not rocket science, is it?

From contributor C:
Spraying dye stain on raw wood or after a sealer coat is totally a matter of the "look" you are trying to achieve and personal preference. Generally, dye over a sealer will give you a more uniform color with slightly subdued grain characteristics. This is due to the color being on top of the wood giving it a "tinted glass" kind of look. Dye on raw wood tends to greatly enhance the "wood's character" because the wood fibers are being colored by the dye. So, depending on the species of wood, it is up to you to decide which process will give you the result you are looking for.

From contributor A:
Take two sample panels, and do a test, leave one raw and seal the other. Then spray a stain over both panels. And then apply clear coats. I'm sure you will see the difference - they both have a place in finishing, and they both have pros and cons. You may prefer one technique on certain wood or finishes, and like the other for other finishes and woods. I suggest you add both of these techniques to your finishing arsenal.