Achieving Uniform Stain With Tinted Shellac

[Leo Butler]

Having achieved some measure of success recently in matching color using shellac with TransTint dyes, I'd like to work on a reliable application method to use it in the future. I'm going to practice on a shelf I'm adding to an entertainment center (yes, quite the dinosaur bit of furniture these days) which is poplar-edged maple plywood. The entertainment center is alder so this is non-ideal, but it wasn't worth spending much money on as this will be a short-lived addition. The poplar front edge will be all that anyone sees on a regular basis but this is a good opportunity to work on process.

Brushing on the tinted shellac results in a hot mess. How fast you move the brush, overlaps, gaps... lots of sanding and touch-up work needs to be done to somewhat normalize the color and the results aren't sufficiently uniform. Suggestions have been made to spray, and I can go that route but I think this may not be a panacea for color uniformity. I have both a HVLP conversion gun and an inexpensive Earlex HVLP that I need to get accustomed to using on my projects so happy enough to give it a try.

I searched the forum and found a lot of recommendations for various situations. Spraying as the first coat seems to be the most common suggestion, but at least one involved flooding the wood surface with the tinted shellac; I'm having trouble visualizing how that would work. But I'd certainly like to have a reliable manual application method in my finishing repertoire.

Thanks,

- Leo

[Jim Becker]

If I'm using a tinted clear of any kind, shellac or waterborne, spraying is the only way I'd go to avoid the "Polyshades" plague.

[John TenEyck]

If all you have to color is the edge you can do it with nothing more than a paper towel. If you have to do the whole shelf it can be done with a brush, but it's not easy. Using Behkol shellac thinner slows down how fast the shellac sets up and gives you a little longer time to apply it, but it's still not an easy task. Spraying is by far the easiest way.

No matter which way you apply it, it's best to do it as several coats. That allows you to sneak up on the final hue, and even adjust the color if needed. Just as important, if you miss a spot with one coat you will get it with the next and over 2, 3, or 4 coats the color will look uniform. In all cases, never go back over what you have already brushed or wiped.

Flooding on shellac sounds like a recipe for disaster. Perhaps the author meant to say that shellac should be flowed on; that is, when brushing shellac it should flow out of the brush from start to end of the brush stroke. As I said, you can't go back and forth over shellac like you do with paint, so it has to freely flow out of the brush in order to cover the surface.

John

[Phil Mueller]

Another manual method I would try (although I’ve never done it with tinted shellac) is to pad it on with a French Polish method. And as John said, the first session may not be even, but subsequent sessions should even it out.

[Leo Butler]

If I'm using a tinted clear of any kind, shellac or waterborne, spraying is the only way I'd go to avoid the "Polyshades" plague.

Do you usually try to nail the desired shade in one coat, or spray multiple lighter coats?

My recent color adjustments on that maple edging were a one-shot deal, and the amount of dye added to the shellac reflected that. I could see going lighter and doing multiple applications, but the thought of doing multiple sprayings on a test board to determine if I've got the right color makes me think this is not the way to go about it.

[Leo Butler]

If all you have to color is the edge you can do it with nothing more than a paper towel. If you have to do the whole shelf it can be done with a brush, but it's not easy. Using Behkol shellac thinner slows down how fast the shellac sets up and gives you a little longer time to apply it, but it's still not an easy task. Spraying is by far the easiest way.

No matter which way you apply it, it's best to do it as several coats. That allows you to sneak up on the final hue, and even adjust the color if needed. Just as important, if you miss a spot with one coat you will get it with the next and over 2, 3, or 4 coats the color will look uniform. In all cases, never go back over what you have already brushed or wiped.

Ah, I should have read further before posting my already-entered-but-not-yet-posted follow-up to Jim. Spraying it is.

I'm pondering how dark to make the tinted shellac. Would applying it to a test board with a foam brush or paper towel when I'm intending to actually spray it imply that I should thin it down for spraying once I think I've reached the desired color match? Or do I just adjust the amount of finish I'm allowing out of the spray gun and use the "full strength" finish?

[Leo Butler]

Another manual method I would try (although I’ve never done it with tinted shellac) is to pad it on with a French Polish method. And as John said, the first session may not be even, but subsequent sessions should even it out.

Phil, I have that very same question in mind - I had read about padding on shellac and my interest is piqued so I will try it sometime, but the super quick dry time makes me think I'd end up with some of the same color consistency issues. Maybe it would even out though, as you suggest. I think I'll need to simply dedicate some scrap to an experiment.

[Frank Pratt]

I've had some success with just lightly tinting the shellac & then applying multiple very light coats so the brush stripes even out. It's acceptable, but spraying would be a lot easier.

[Edwin Santos]

Hopefully I'm not muddying the water here, but one more opinion on this....

Since you have the capability to spray, you should do so because it is the most efficient way to put down a consistent coat.

Regarding tinting the shellac, technically called toning, this is a good time to find your patience.
It is much better to tint to a weaker strength and sneak up on the final color through multiple coats. This will help the blending and consistency also. I'm talking like 4 or 5 coats, even more. This does not add as much time as you might think because shellac dries so quickly and each successive coat sort of melts into the last one thus you don't have to wait an extended time for curing like you might with other finishes.
In my case, I might spray the toned shellac, and go do something else for 15 or 30 minutes, then come back and spray the next one. I use a finer tip on my spray gun, 1mm, and aim for misting on the coat in methodical passes rather than spraying a thicker, continuous coating. To prevent striping, I usually alternate my passes 90 degrees each pass (one pass north-south, next coat going east-west). The shellac cut is very weak, like maybe 1/2 lb cut so what you're spraying is mostly solvent with some shellac and some dye. With this dilute solution, it will feel like you are not doing anything, but you will be surprised how quickly you will sneak up on the final color you desire. The secondary benefit of the dilute solution is that it will flow out much better. The alternative would be to try and do it in one or two shots which will invariably lead to problems, most likely inconsistency and overshooting your desired color.

Your last coat which will be your topcoat will not be a toned finish, but a final finish coat of whatever you choose be it shellac or another topcoat, and this will be sprayed conventionally (or if a non-alcohol based finished, you could wipe or brush).

Some very capable finishers have been known to use two different toners and spray them in separate coats thus creating a unique level of depth and even iridescence by layering on subtly different colors on different layers.

For anyone interested in padding, it can absolutely be done following the same instructions, keeping it very dilute and being very patient. Same goes for tinting a waterborne finish. I have also tinted varnish and oil based finishes with artist colors and japan color, and this is very easy to do also.
No doubt, toning well is a skill and an art but once it clicks, it will be a very good technique to have in your finishing arsenal.

regards, Edwin

[Prashun Patel]

Tinting shellac is possible, but not necessarily the best way. The issue is that to build up color, you have to also build up the shellac. Wiping or brushing it on will be messy, will move the dye and shellac around, and will result in streaks.

A better way is to flood on the first coat without any binder. That is, dye mixed in water or ethanol (compatibility varies). You can spray it or wipe it on. The first coat will go on very well. It's hard to get the second and third coats to go on deeper if wiping because you will also remove some of the initial dye with the rag, so it's better IMHO to spray these coats on. This will allow you to build up the color. Thinning in water may feel the safest, but it also raises the grain and dries slower than spraying it in ethanol.

Once the color is built you can spray on your top coat directly.

Adding color to a top coat like shellac or another sealer can then be sprayed on top if you really want to blend and fix problem areas; sometimes portions of the wood won't take the color as well as others, or they get rubbed off say on corners in between top coat sanding. In this case, spraying the color on with a binder helps it sit closer to the surface, and locks it in around problem areas like corners.

Finally you can topcoat with a proper top coat. I don't like doing the final top coats with any tint, because some of that dye sits near the surface and can be rubbed off during final polishing if you're doing that.

The other issue with tinting shellac (anything other than amber) is that it's really hard to hit a target. Using a clear sealer (Target makes a good, waterbased one) allows you to see the exact color in your mixing cup that the toner will go on as.

[John TenEyck]

Do you usually try to nail the desired shade in one coat, or spray multiple lighter coats?

My recent color adjustments on that maple edging were a one-shot deal, and the amount of dye added to the shellac reflected that. I could see going lighter and doing multiple applications, but the thought of doing multiple sprayings on a test board to determine if I've got the right color makes me think this is not the way to go about it.

No, never, I always apply multiple coats of toner to build up to the final hue desired. Even spraying it on won't give you a uniform color in one coat. As was said, the final layer of shellac will not be very thick if you use a 1/2 to 1 lb cut. And, yes, the best way to mimic what's going to happen on your actual project is to prepare your test boards the same way. So if you plan to spray the actual work, then spray the test boards. I sometimes wipe the toners on my test boards even though I'm going to spray the actual project, but I recognize that I might need more or less coats than what I wiped on.

As Prashun said, you can dye the raw wood first and then switch to toners. There are no absolute rules except to use multiple layers to build up to the hue you need.

Practice. You'll learn soon enough what works best for you.

John

[Jim Becker]

Do you usually try to nail the desired shade in one coat, or spray multiple lighter coats?

If you're trying to sneak up on a specific color, then it's light coats as the color is cumulative. This can be an advantage if you're also looking to do some highlight shading/toning, too. But light coats are necessary with shellac anyway. You want the thinnest possible finish you can get the job done with when using shellac.

If you're shooting for a general color, you don't have to be as fussy.

[Leo Butler]

I mixed a batch of 1/2 lb. dewaxed amber shellac flakes and added the TransTint then tested with a quick wipe on the scrap plywood. The color was very close so I went with it. Applied three light coats with my HVLP conversion gun and got a nice uniform color. The poplar edging didn't go quite red enough so I masked the plywood and brushed on some of another batch of shellac that had just the right extra red tone and viola, it's done. Topped with a couple of coats of lacquer from a rattle can and it looks pretty good. Not perfect but much better than just "it'll do". My wife was impressed so I'll avoid pointing out any flaws. She thinks it's perfect, ergo it is perfect.

Thanks to everyone for the tips and techniques. I'm going to try Prashun's method on the remaining piece of scrap to see how it differs, after I get another project wrapped up.