Grain Filling with Shellac

[Scott Holmes]

shellac cuts are not measured weights of alcohol (DNA). It's pounds or oz. of shellac in a liquid volume of alcohol. Easy way to measure is 1 oz of shellac flakes in 1 cup (8fl oz) of DNa = 1# cut 2 oz flakes in a cup of DNA = 2# cut.

If you are using pre-mixed shellac (I use and recommend flakes) the seal coat is a 2# cut and the others are 3# cuts. Only the seal coat is de-waxed.

[Prashun Patel]

1 gallon of DNA weighs APPROXIMATELY 8 lbs.
So by weight, a 1# cut is approximately a 1:8 ratio of flakes to DNA.

Because vol-> wt conversions are non-intuitive for me, I usually use the above rule of thumb and it works fine.

In fact once you mix up enough of the stuff, you can almost eyeball it.

[Joel Wesseling]

I havent yet tried DNA only 99% Iso and it takes a long time to dissolve the shellac but Its supposed to be less harmful I believe

3# cut for finish coats. Is this good

Joel

[Scott Holmes]

A 3# cut is a bit heavy; the word that worries me is "coats". I use 2 or 3 coats of ~3# cut to fill the grain, 95% or more is removed. Today I filled the grain on a piece of walnut with shellac took 4 coats because I was using a 2# cut. Removed all but the shellac left in the pores.

NOTE: Shellac is not to be built up in a thick layer (as you can do with lacquer or varnish). The perfect shellac finish is the thinnest possible film that is flawless. A french polish finish looks beautiful and deep; it is actually very thin.

[Harvey Pascoe]

Scott, this pound/cut business seems very confusing as it is measuring pounds to gallons. A gallon of alcohol weighs just under 8 lbs so the ratio by WEIGHT of a 1 lb cut (one pound to one gallon) is is 1 part shellac, 8 parts alcohol by weight or 1:8. A 1:4 ratio would be the same as a 2 lb. cut. Have it got that right?

I only use very small amounts of shellac, so thinking in terms of pound cuts is kinda absurd. I use a micro scale and a ratio set in ounces to make up a small jar of shellac. If you're doing only small amounts you can use a measuring cup and do it by volume and tho its less accurate I don't think it makes a dimes worth of difference. Its the ratio we're after for repeatability. Micro scales are pretty cheap, about $30 and very useful for other tasks.

[Harvey Pascoe]

Especially with open grain wood, try to lay the shellac on with a single brush stroke. Due to the rapid drying, if you are dragging the brush back and forth, you are pulling the shellac back out of the grain. Single stroke, one direction only and don't worry about any uneveness.

[James White]

What has been your experience with more open grain woods like oak and ash? I tried filling some white oak by padding on a 2# cut. But after about 5 coats. I just figured I would never get it totally filled. Would I have done better applying with a brush? Or was it because I was using a 2# cut?

James

A 3# cut is a bit heavy; the word that worries me is "coats". I use 2 or 3 coats of ~3# cut to fill the grain, 95% or more is removed. Today I filled the grain on a piece of walnut with shellac took 4 coats because I was using a 2# cut. Removed all but the shellac left in the pores.

NOTE: Shellac is not to be built up in a thick layer (as you can do with lacquer or varnish). The perfect shellac finish is the thinnest possible film that is flawless. A french polish finish looks beautiful and deep; it is actually very thin.

[Joel Wesseling]

Today I filled the grain on a piece of walnut with shellac took 4 coats because I was using a 2# cut.

4 coates. I have to be doing something wrong. do you apply with the grain?

Joel

[Scott Holmes]

Padding does not build the shellacvery much; each wipe move the existing along with the fresh coat. Try brushing it as Harvey stated in his 6:06 AM post, today. You will not see posts from me at that time of the morning.

Open grain woods with large pores (e.g. red oak) are better filled with a clear filler not shellac. Mahogany, walnut, white, and ash are about as open grain as I will fill with shellac.

Harvey I now understand your 1:8 system thank you for explaining what you meant.

FYI: my dry oz. flakes in fluid oz. is extremely repeatable; as you said it doesn't really matter that much.

I when I add color to make a toner, I want to know exactly how many oz. of fluid to how many drops of TransTint dye. weighing the fluid seems like an extra step to me.

If the ratio system works for you and other; it seems to work well for you, then I say USE IT.

[Jack Clark]

Open grain woods with large pores (e.g. red oak) are better filled with a clear filler not shellac. Mahogany, walnut, white, and ash are about as open grain as I will fill with shellac

Scott,

I know it's buried somewhere here on "the creek," but could you quickly refresh my memory on what is your favorite method to fill red oak?

Thanks

[Harvey Pascoe]

FYI: my dry oz. flakes in fluid oz. is extremely repeatable; as you said it doesn't really matter that much.

I when I add color to make a toner, I want to know exactly how many oz. of fluid to how many drops of TransTint dye. weighing the fluid seems like an extra step to me.

If the ratio system works for you and other; it seems to work well for you, then I say USE IT.

Well, sir, you put a burr under my saddle to find out whether there is any difference between the fluid ounce and the dry avoirdupois ounce. It is only one gram! So it makes no difference how we do it.

[Scott Holmes]

I would seggest you take a look at CrystaLac Wood Grain Filler. There are others too.

[Jim Mackell]

Scott, I'm working with some old mahogney and making repairs with some new mahogney. I'm planning on staining the new work to blend in with the old. Can I stain my new work and then use shellac as a pore filler before varnishing? I've seen contradictory info in different places and I'd like your thoughts on the correct sequence.

Thanks!

[Scott Holmes]

You can fill with shellac or another filler after staining the wood...

HOWEVER, you must be very careful when sanding, as it is easy to sand through the shellac "filler" and remove the color. There are other options... is the existing mahogany filled? I suggest only filling tops of tables desks etc. Vertical surfaces don't normally need to be filled. Unless your reair would show if not filled.

[Jim Mackell]

Thank you Scott. Yes, I understand about the sanding. I'll generally use something like 40 grit just to level things out and promote adhesion.