Fine Points of Glazed Finish Applications

A long discussion of glaze formulation and application techniques. July 29, 2007

This relates to using lacquer as a topcoat. Usually when I read about glazing, it seems that sealing is a necessary step before proceeding with a second or third glaze coat. Is this accurate? In particular, if using a gel stain as the glaze, why can't I just put one stain (glaze) right over the other (stain) as long as it's dry? I've also heard that if you have some sort of sealer between the glazes, that it will give more depth in the finish. This sort of sounds like a wives' tale to me. I mean, doesn't everything basically melt together anyway?

Forum Responses
(Finishing Forum)
From contributor R:
The reason for sealing in a glaze is so that if you plan on applying a secondary glaze coat, the secondary coat won't melt the first coat, thereby creating a large goopy mess. It seems to me that gelled stains wouldn't make that good of a glaze considering their consistency. Maybe with the addition of some thinners they would be more manageable, however. A good, clean brush is important to applying a glaze coat.

From contributor M:
Yes, it's accurate. That's why we get paid so much for these types of finish schedules. It's more complex, labor intensive, and looks different than just slapping on some stain. They get what they pay for.

From contributor C:
As you can see in the photo, there are many glaze steps I used to accomplish this faux finish. Every glaze step was sealed in and each glaze added depth and character and dimension to the overall look. Normal high end glazes are custom made by the individual, with a starting formula of 20% colorant, 70% mineral spirits, and if longer open time is required, 10% boiled linseed oil. Of course these amounts can be adjusted when the need arises. Many times when doing glazing, there is a need to create a dark finish, and with oil stains this is more true than with dyes. Glazing helps uniform out blotchy or uneven panels and is more appropriate than toners and gives a look that cannot be achieved in any other way. Anyway, as the photo shows, sealing in every coat can achieve some beautiful results.

Click here for higher quality, full size image

From the original questioner:
Maybe I'm missing something here, but the only glaze (Gemini brand) that I have tried dried very quickly and was not as workable as the gel stains (Old Masters) that I use. The gel stains won't melt anything once they are dry. Not sure about the Gemini glaze, though. Maybe normal glazes don't actually ever dry. I don't know. They also say that there is little or no binder in glazes, which I find weird, because the Gemini glaze takes a lot more work to remove (with MS) than the gel stains. And it seems there is always a very slight tint left behind.

As far as using gel stains as a glaze, both Bob Flexner and Jeff Jewitt use them as glazes. So that's good enough for me. After all, glazing is staining a sealed surface. Just a new word to label the new product to generate new money.

Contributor C, yes, I know glazes add depth and character. However, is the extra step of separating the multiple coats with sealer necessary? Of course I am assuming that glazes dry like gel stains dry (a day or two). Now, maybe sealing between coats is a simple way to actually speed up the dry times? But your sample board doesn't show much other than it gradually gets darker. Have you tried the same experiment without sealing between coats and seeing if you can see a difference? In the end, it all melts together anyway. As far as mixing your own glaze of 20/80% color/MS, that would seem a little thin to be a glaze. I also find it very hard to work with anything that has been thinned that much with MS, as the MS becomes sloppy and streaky. Maybe you are referring to a toner, though?

From contributor C:
I'm sorry you can't see the detail better in the photo. Wiping the glaze off in certain areas produces the streaks and light accents around the burls. In other words, it would look just as dead as the first color step in the photo step board. Anyway, yes, sealing in each coat of glaze is critical since the amount of binder is minimal. If you did not, the mineral spirits would just re-dissolve the color and defeat the objective of double or triple color application.

Long before Jeff and Bob were even finishing, the standard glaze I told you of had been used for decades. My grandfather used it, my father, and now I. In the 43 years I have been in this business, it has never failed me and has produced some of the most exotic high end looks that you will find. This type of glaze is a floating glaze, meaning that it can be sprayed over shortly after application (after the mineral spirits have evaporated). The clear coat then lifts the glaze to a small degree into itself. This in turn shifts the color to some degree, hence the need to put it on in a thinner condition to sneak up on the exact color you desire to achieve. Can it be made thicker by adding more pigment? Yes, but too much pigment is not a good thing. That's the problem with today's finishing techniques - everybody wants the quick fix. I am in the dark, to a degree, on the gel stains or their makeup or chemistry, since I don't use them.

From contributor R:
I don't know of any glaze that takes a day or two to dry. Of course, I'm not using any store bought items. The glazes I mix up are dry in an hour and I can begin the spraying steps shortly thereafter. You're on the right road by reading some books, but generally speaking, it's really the knowledge that's gained from the experience that decides what glazes work best for you.

From contributor J:
I have worked with two types of glazes. Wet glazing with mineral spirits or even 130 solvent for a smeary, wiping and brushing look, and dry glazing, which dries very fast into a powdery film which is brushed off quickly and very clean.

Each has its ups and downs. Wet glazes are slow drying because it gives the finisher many options on what he is trying to achieve. A dry glaze is pretty much used only in fast production lines and comes off easy but is very messy. It's almost like baby powder, but some people like it.

From the original questioner:
Contributor C, looking at your picture, I would tend to call that more toning than glazing. Well, actually, it's toning and glazing at the same time, I think. This is sort of the way that I have been using stains, i.e. glazing over sealed wood in a toner type of fashion. I still can't figure out how you make it work with just MS and color and so diluted. But I guess with the generations of know-how and touch, it's easy.

I like the concept of a floating glaze wherein the colorant has no preference to its solvent so you can shoot it almost immediately. I'm going to try some toning (spray) with a naphtha-colorant blend and see how that goes, as a lacquer toner is just too permanent at this juncture. I think it will be hard to see the color, though, as the naphtha dries so fast.

Contributor R, I say a day or two just to be on the safe side. I am using stain to glaze, though. So, it takes awhile to dry. As I said, I don't care much for the Gemini glaze that I tried. And I get kind of tired trying every product under the sun.

From contributor C:
Of course you can tone with mineral spirits or naphtha or any aliphatic solvent that won't soften your clear coat and end up with a tone that's fairly uniform. In fact, when I am looking to toast edges or darken certain areas of a finish, I often use a similar method, either with a touchup gun or an air brush, and if for some reason I go too dark, I can always wipe it back off (before) it is sealed and redo the process again. I even make up more concentrated mixtures and use them with a smaller gun to shoot in to edges and profiles which I let dry for several minutes or more and then use a dampened rag with mineral spirits to wipe the excess off, leaving behind a very uniform sunken profile area that is perfectly uniform and high end.

There is nothing you can't do with this glaze that I know of. Glazing is a process that allows you to produce a very uniform application of color upon the surface with a good brush that looks extremely good and does not develop areas of light and dark on, let us say, a raised panel door, like trying to tone color onto a panel. When you use a gun to apply color even with low pressure, the air from the gun tends to not allow the color to get in to profile places (next to raised moldings), and those areas stay light in color and there is usually a defined area of lightness that has to be dealt with one way or another. Now air brushes and the like can minimize this a lot, but even then it never looks as good as a finely accomplished hand glazed finish does. Glaze allows you to spray, rag, brush, or sponge the color glaze onto the surface however you please, and then brush that color out back and forth in both directions, wipe the excess off in between to release excess color onto the rag, and then pick up more excess color until you achieve the amount of coloration you desire on the piece it's applied to. The brushing first starts out with fairly heavy pressure and lessens the closer you get to reaching the desired color. All the time you are cleaning the excess color off the brush on a rag and picking more up when you start brushing the surface again. This is not some two or three minute spray-on process we're talking about. For example, I can spray tone a flat kitchen cab door pretty uniform with a standard air spray gun making two or three passes in 4 or 5 minutes at the most. To glaze that same door with a brush would take me at least 20 minutes or more if I was looking for near perfection. When I am through glazing the surface on first class work, there are no visible brush marks from a foot away and most people assume it was done by spray techniques, but it's not. Go to a high end shop and watch any good glazer go through the process. That's the only way you will really understand.

From the original questioner:
Thanks. Do you use pigmented colorants, UTCs, Japan colors, or some sort of oil based dyes? Is there such a thing?

Twenty minutes for a door? LOL. I've just finished up my last of 25 doors' first glaze coat. They took about 40 minutes to an hour per side. (Well, the backs were pretty quick.)
I tried my naphtha/toner idea today. It seemed pretty blotchy using the universal colorants. I'm wondering if Japans are any finer. I'd like to stay away from the varnish binder maybe, though. The toner idea is basically to darken things up a bit without accenting the grain.

From contributor S:
Perhaps I'm missing the question which I believe you originally asked, which was why do you have to seal after each color of glaze? Answer: to prevent the next color of glaze from reactivating and smearing the first color of glaze. These are not catalyzed systems solvents will resolvate the glaze and you're back to square one without the protective seal coat.

MLC makes a very nice glaze base to which you add 844 colorants. This is a fast working glaze that's tons faster than the gel stain. This is the way to go.

From contributor C:
You can use any colorant that will mix with any aliphatic hydrocarbons. Mineral spirits, vmp naphtha, or even kerosene, just a little to keep your glaze open so that you can brush the glaze out more. General Dispersion Pigments (GDP) from Huls work very well. Try to stay away from the 844's - this type does not work with mineral spirit types. Personally I use Delta's colors in oil, ground in linseed oil. And in a pinch I will use Mohawk's universal colors. You need to find one of these or similar product and get familiar with how it works. You need to go to a high end shop and watch how the glazing is accomplished so you can then practice on your own until you have the technique down pat before you will ever accomplish the work in a reasonable amount of time and be profitable in doing so!

Second point: The system I am talking about is not recommended for use with thermoset systems (cat. varnish, lacquer, etc.). My system needs to be a thermoplastic finish that can be built beyond 4 or 5 mils nitro, acrylic, shellac, etc. If you're using cat finishes, you would be better off using a glaze base like Mohawk or ML Campbell because they are made without any oily substances that would interfere with intercoat adhesion. You can use the 844 type of colorant with these and get fairly good results without having to be concerned about peeling or flaking of the finish. Whichever way you decide or need to go please find someone to show you how to properly glaze with them.

From the original questioner:
I am a little confused. Are you saying that it would be safer to use an MLC or Mohawk base than to just use universal color and min spirits? Or is the linseed oil part of your formula the weak link?

I am using a pre-cat lacquer (Magnamax). And I learned midstream that Magnamax does not burn into prior coats like regular lacquer does. This has created a few dilemmas wherein if I want a few glaze coats, then I need a few thin lacquer coats to keep the build down. They say that Magnamax is self sealing. But I'm a little unclear what that means.

Thanks for suggesting that I visit a high end shop and watch. I have done this in the past. My main problem at the moment is not so much the application or touch, but the chemistry.

From contributor C:
Yes, what you call the weak point would be the drying oil part of the glaze. When you use this glaze, if left for an extended time, it will create a film of oil that could wrinkle or lift if sprayed over. If you just used mineral spirits and colorant, this would not be the case unless the colorant was a color in oil to begin with. If using my glaze, you need to spray over it as soon as possible after you have glazed to the proper color. Within a few hours, when you do the solvents in the NC or acrylic will lift the color to a small degree into the finish and allow for the coating to adhere to the coat underneath without having to worry about flaking or peeling later on.

Also what happens is a color shift usually to the lighter side, which is good, for if it shifted darker, that would be a problem. And another thin coat of glaze is usually applied to make up for that color shift once it has been sealed in. Here is how it goes. Base coat color or stain and seal, glaze piece to what you believe is the correct color, seal glaze in, check the color with sample and if light, which it usually is, reapply another coat of glaze to bring it to the final color. The second coat of glaze can be thinned more or even applied by rag and wiped off with clean rag at times if the color is really close.

If you want the high end results, though, you will have to stick with thermoplastic resins that can be built up without worry of surpassing recommended mil thickness. I have worked in the top shops in Florida and all the high end work is done this way for kitchens, bathrooms, entertainment centers, etc. without any re-dos in the last thirty years. That's why they pay people like me the money they do - there are few of us left that can glaze a piece so good that you can't even see the brush strokes.

As to your confusion – yes, in a cat system oil will interfere with the adhesion. And the other reason is you cannot do a first class glaze over a sanded surface; it has to be glass smooth. And most if not all cat systems require at least scuffing in between for good adhesion once they are out of their window. I don't trust any thermoset products when it comes to first class work and if you pinned a chemist down on the subject of which type of system was the safest to use as to recoating, ease of repair, or touch up and recoat, they would tell you to stick with the thermoplastic coatings if it would not affect their job.

From the original questioner:
Here's my schedule so far on a kitchen cab refinish of oak cabs I'm doing:
- Strip, sand
- Spray tinted Bins shellac based primer, sand
- Pore filler
- Sand
- Second light coat of Bins
- Sand
- Wipe on old masters gel stain, wipe off. Very thin coat. I didn't thin it. I wiped most of it off.
- Let dry
- Sprayed a 50/50 coat of ML Campbell Magnamax pre cat lacquer as a sealer (misted first). Lots and lots of dry time for every step. The pre-cat is about halfway through its 120 day cycle.
- Toned with a mix of the Magnamax (1 cup), ML Campbell thinner (2 cups), Old Masters gel stain (10 tablespoons).

I am at the point now of having realized that the Magnamax doesn't bond to previous coats. So, what I have is the first coat of Mag which probably/maybe/hopefully bonded with the shellac base and locked in the stain also. Then a very thin coat of Mag with the toner. I don't think I am anywhere near 4-5 mils. But I am concerned about the stacked up thin layers that don't melt together.

I have applied blue painter's tape and pulled it off and I didn't have anything come off. I tried to strip one of the doors with lacquer thinner and it barely touched it. My point being that the finish is on there. Or is it?

I still would like to tone some more using glaze, color and MS or stain and then glaze using glaze, color and MS or stain (2 more coats at least), but I just don't know how to proceed. I'm concerned about the finish failing somewhere down the road.

I'm also concerned about the thickness of the film as I lock in these coats. (I'm getting a wet mil gauge tomorrow). And/or whether Magnamax is even made for this kind of creative stuff? I just picture all these slivers of coating just laying on top of each other.

I don't know what thermoplastic resins are.

From contributor P:
As a two decade plus practitioner of the old faux arts, and with a strong house painting background - as opposed to a wood shop training - my glaze of choice has and will continue to be that of the oil or alkyd variety. As a marbler and grainer as well as a wall and cabinet glazer, near the very top of my criteria is open time. Of course as any experienced lad knows, there are a goodly number of ways to impart sufficient open time to most any oil or alkyd glaze. That established, it is still key to have at least a somewhat reliable drying time - say overnight.

That said… no! I never seal between glaze coats! Why would I? I have never experienced any problems adding glaze coats over one another, provided each previous coat is dry. Now if you are adding something hot into the mix, that would be another story. But if you're dealing with varnishes, turpentine, etc., then you need not seal for safety's sake -just as long as your previous glaze coat was given adequate drying time.