For the past weeks I have been telling you that if you know the recipe to your wiping stain then that knowledge gives you the ability to modify the pigment load in your stain or to create a shader. Why would you want to do this? Perhaps you are experiencing problems achieving the intensity of color you are looking for. But be careful here. Taking the easy route and “fogging on” a wipe stain to increase that intensity will lead to serious adhesion/delamination issues.
This week and next I am going to talk more in detail about proper methods to use. “Fogging on” a wipe stain is NOT on this list. My aim is to give you some tips about the correct way to proceed in intensifying the color you want beyond your wipe stain. Even when you go well beyond the recommended pigment load in a wiping stain that sometimes is still not enough. Sometimes you just have to add more color to achieve what you want.
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When you contemplate going in the direction of shaders, toners, and spray stains, you need to think hard about the spray equipment you have and use. If you are going to “fog on” a shader or toner, you are going to need equipment that will allow that to happen. A good quality HVLP, conventional, or compliant spray gun is essential. An assortment of different sized needle/nozzle sets are handy to have. I doubt very much that an airless pump or an air-assisted airless pump will be of any use to you. Though, one of my colleagues suggests that AAA is the way to go.
We are now talking about a different form of color application. Spray-only stains, dyes, toners, and shaders are all low in viscosity. In order to apply them evenly, you need to be able to control the fluid as it leaves the spray tip. You need to have control over the atomization air pressure as well. Once the air and the fluid leave the tip, the volume and pressure of that air create turbulence that affects where the color goes and how it looks once it hits the surface. Too much air and a lot of that fluid will never make it to the wood. Too much pressure creates excess turbulence that, in turn creates halos in any and all inside corners. Remember, you cannot “force” the color into inside corners.
Your skill as a “gunslinger” comes to the fore in this type of work. Your understanding of the need for a larger or smaller diameter needle/nozzle set, the adjustment of the fluid control, the fan pattern, and the atomization air pressure are only the beginning. Your mastery of your own hand-eye coordination and how that affects the distance between the spray tip and the wood’s surface in conjunction with the speed with which you move across that surface are critical. And least I forget, the amount of overlap from one pass to the next is also important.
Other than that, it’s a walk in the park. NOT!!!
All that I can do in the course of an article is point out the issues to you. It’s up to you to practice diligently to improve your skills with a spray gun. It takes time. It takes experience. Don’t gamble a project on an “I think I can” that may end up an “I wish I hadn’t.” There is nothing more expensive than regret.
If your background includes automotive fender repair and the blending and shading of color to repair a ding in a car’s exterior, then you probably get the approach that I am suggesting.
I find that car painters, as a group, catch on to gun technique as it applies to wood working shaders and spray stains faster than most. That’s because their gun technique has to be flawless to get a whole car… or just a fender repainted without stripes and other obvious issues. It’s that mastery of gun technique that give them a leg up on us guys who have only applied a clear to wood.
My most often repeated “Bernie-ism” is speed and distance are your friends when applying color with a spray gun. Right after that, my next bit of advice is that you want to sneak up on the intensity of color that you want without blowing past the intensity of color that you need.
What do I mean by that? Well, when you pick up a gun and go to work for the first time, it won’t take long for you to figure out that I’m right. I will suggest that your initial results will be to get too intense a color and that rather quickly.
• Turn down the atomization air pressure.
• Turn down the amount of fluid coming from the nozzle.
• Experiment with several needle/nozzle sets (go smaller) to find the one that gives the most even pattern within the parameters of lower atomization pressure and reduced fluid delivery.
• Don’t be afraid to dilute the pigment load in your coating. That will make it easier for you to be “sneaky.”
• The higher you are off of the surface you are coloring, the more gently the spray will land on the surface and
• The more diffused the intensity will be.
• The faster that you move the gun over the surface, the less color you will impart on that surface.
• The more gentle the spray, the less haloing in inside corners.
• AAA units are known for their gentle spray. That’s why my colleague suggests them for coloring.
• Put some mineral spirits in your gun and practice on some corrugated cardboard or some brown paper to test your setup and your skills.
A footnote to the AAA statement above. Another colleague was bound and determined to prove that AAA was the best method to apply automotive clears to cars. He did a LOT of sanding off clearcoats before he proved that it could, indeed, work. You better have some skills to bring to the party if you’re out to prove that AAA is the way to apply color!
We are going to end here and take up the next phase of this next week. I hope that you have found this useful.
Until next time…spray on!
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