Help me understand shellac

[Louis Brandt]

Hello,
Would someone help me understand the use of shellac in a wood staining process? Many people have mentioned using shellac in their staining process, and being a newbie when it comes to staining, I just don’t understand how shellac works. I’ve never used it. I’ve watched Norm enough to have noticed that one of his staining techniques has the following steps: oil stain, then seal with wax free shellac, then grain filler paste, then stain again with gel stain and finally, applications of poly.
My question is, what does the shellac do? I had always assumed that shellac was a substance similar to polyurethane and therefore wouldn’t accept a stain on top of it. But based on Norm’s technique and what I’ve heard from others, this apparently isn’t true.
Can someone give me a brief explanation of how shellac works? Can you apply it, let it dry, then just put gel stain on top? Do you have to sand the shellac before putting on the gel?
And why does everyone talk about shellac flakes? Doesn't shellac come in liquid form in cans? Please forgive my ignorance, but as you can see, I know nothing about shellac.
Louis

[Cecil Arnold]

Welcome Louis. Rather than giving you a long thesis on shellac, I would recommend you find a good book on finishing, but briefly shellac is a great finish that takes some time to learn. The different distillations of shellac from button to super blond all can add character, highlight the natural color of the wood, and "pop" the grain, depending on what you are looking for. Finally, shellac is about the best sealer/barrier coating there is IMHO.

[Rob Millard]

If thinned enough shellac will allow a stain, be it oil or water based to penetrate. The reason for using shellac in this manner is to control blotching. Of course the shellac will not allow the stain to darken the wood as much as if the stain were applied to raw wood.
The way Norm uses it, the shellac acts as a barrier coat. The shellac in this instance is applied more thickly, and a scuff sanding help provide a tooth for the gel stain.
Of the two methods I prefer the “Norm” way; it provides great control, and in the case of the period reproductions I make, it can mimic an aged finish.
Rob Millard

[Howard Acheson]

>> one of his staining techniques has the following steps: oil stain, then seal with wax free shellac, then grain filler paste, then stain again with gel stain and finally, applications of poly.

OK, let's go over this step by step. First, in addition to being an excellent finish in its own right, shellac has a number of other uses. One of these uses is as a sealer or barrier coat between stain and finish or dissimilar finishes.

In the above, the shellac after the oil stain, seals in the stain so it is not affected by the solvents and thinners in the grain filler. At this point, many would apply another coat of shellac to seal the filler. A gel stain does not need to penetrate the wood to color the wood. Gel stain is really more like a paint than a stain. It sits on top of the shellac and the shellac again provides a barrier to the solvents in the gel stain. At this point a clear coat like varnish or poly varnish can be applied.

What the above means is that you would not need to apply the shellac if you didn't have dissimilar materials that could be dissolved by the solvents in the following finishing material. If you were just applying an oil stain followed by a varnish or poly varnish, shellac is not necessary as a barrier coat. However, if you use a waterbased dye stain and plan to use a waterborne clear finish, the waterborne clear finish would dissolve the waterbased dye and muddy the finish. In this case, a "spit" (1# cut) coat of shellac will prevent this dissolving.

A point to keep in mind is that dewaxed shellac must be used if you plan to overcoat with an oil based poly varnish or any waterborne finish.

[Louis Brandt]

Howie,

Thanks for the reply and the explanation about using shellac. I'm not bound and determined to use shellac, but what I'm trying to accomplish is to get a really dark color onto this solid oak that I'm using for my fireplace surround. I suppose that when I say "get a dark color onto the oak", what I really mean is that I want to get a uniform dark color onto it. The testing that I've done with an oil stain so far just darkens the pores of the oak, but leaves the other areas lighter, so that I wind up with something of a series of lines or streaks. I do want the finished product to look like it's been stained, but I don't want large variations in the finish.

I have ordered some transtint dye, and when it comes in, I plan to do some testing with it. If the test looks ok, my plan is to use the dye diluted with water to dye the oak, then use an oil stain on top of that, followed by a wipe-on poly.

If what I have in mind needs modification, I would appreciate your input, because I am not ultra confident in my plan at this point. Any ideas will be greatly appreciated.

Louis

[Mike Cutler]

Louis.

Test out some Bartley's Gel Stain on some scrap material that is the same as the fireplace surround.
I don't really like the Bartley's, because it tends to do what you are trying to do. It's a little bit too uniform for my taste.
Test it with and without a grain sealer. It may be what you are looking for.

[Louis Brandt]

Mike,
Thanks for the info. I've never heard of Bartley's stain, and I don't think that I can find it locally, but I've just found a website that sells it.

Let me ask you this: Have you ever used Minwax's gel stain? I've just finished trying Minwax's gel stain on a test piece, and it still didn't do it for me. Do you think that Bartley's gel stain is very different from Minwax's gel stain? I certainly don't mind giving it a try, and I'm in no hurry to complete this job, since I'd rather take longer and get it done right.

Louis

[Carl Eyman]

I'd like to put in a plug for a water based product, Fuhr's #155. It is water thin and soaks into end grain quickly and completely, but tends to stay on the surface of long grain. So if you are dyeing a cabriole leg, for instance, you can put it on the leg before the dye, sand it off (very easily) and then apply the dye. The #155 will prevent the dye from making the knee of the leg too dark, but because you've removed the #155 from the long grain not interfere with the coloring there. I used it on the 10 dining chairs at Jeff Jewitt's sugestion and was very pleased. Homestead Finishing sells it. The fact it comes off the long grain easier than shellac does makes the difference.

[Howard Acheson]

Louis, you have been round and round with this issue on the WoodNet. There is no new info that you can expect here.

To summarize. If you want a dark color on oak, first use a waterbased dye then use a darkl gel stain. That's the same answer I and other have given you already. It's not going to change.

Just go ahead and test it on some scrap and get on with it.

[Louis Brandt]

Hello,
I sincerely apologize for my continued posting on this issue.
Louis

[Mike Cutler]

Mike,
Thanks for the info. I've never heard of Bartley's stain, and I don't think that I can find it locally, but I've just found a website that sells it.

Let me ask you this: Have you ever used Minwax's gel stain? I've just finished trying Minwax's gel stain on a test piece, and it still didn't do it for me. Do you think that Bartley's gel stain is very different from Minwax's gel stain? I certainly don't mind giving it a try, and I'm in no hurry to complete this job, since I'd rather take longer and get it done right.

Louis

I've never used the Minwax Gel Stains, so I can't really comment.

Finishing is one of those "acquired" skills. Some folks just seem to develop a knack for it. I'm a trial and error guy myself.
I have a few books on finishing to help me more accurately predict the outcome, but I am by no means an expert.

Get a couple of different books on finishing. I like Flexner's book on finishing myself. It focuses less on specific technique, than on simply how finishes are made, why they react chemically the way they do. How one will react to another.

Grab a bunch of different types of finishing products and start to experiment. I treated it like an investment. I could spend a couple hundred bucks on the newest whiz bang jig, or I could spend a couple hundred on a cabinet full of finishing stuff, so I could learn to "finish" the stuff I made with the last "newest whiz bang jig".

[Jerry Olexa]

I'm no expert on oak finishing but in my limited experience, it is a Difficult wood to finish for that look u want. The nature of the wood, its open pores, etc add to the challenge. I'd go w the above advice (gel etc)on some scraps. Its prob the best you can do. G'Luck