Grain Filling with Shellac

[Harvey Pascoe]

Since this forum has relatively few topics I decided to start a new thread as a continuation of a previous.

I think it was Scott Holmes who suggested to try grain filling with shellac. Sounded improbable to me, but last night I did some experimentation. After thickening up my jar of shellac by adding more flake - at this point I have no idea what the ratio is - but I'd guess around 1:3 or 4. Then put 3 coats on India rosewood, a moderately fine grained wood, sanding between coats. At least from what I can see under magnification, it seems to be working well, but only time will tell after applying the first coat of varnish.

Several things occurred to me about grain filling and one is that capillary effect plays a major role. Capillary effect, along with osmosis, is the mechanism that makes the tree grow. Capillaries conduct fluid along its length via a method known as aqueous tension. However, when the cell is exposed by cutting the wood, the effect is altered so that capillaries, particularly short ones, can also eject the fluid we attempt to fill them with. This becomes very apparent when we apply varnish or acrylic to very porous wood like mahogany or walnut. The finish is ejected from the exposed cell and mounds up along the upper edges of the cell, so that if you don't sand between coats, the finish just keeps mounding up and the cell doesn't get filled. Think of this like a ditch digger who throws the dirt up along the margins of his ditch.

Therefore, when we finally end up filling the cells with finish, what we are really doing is not filling, but bridging the upper opening of the cells until they are closed, unless we find a way to prevent the cells from ejecting the fluid.We see what happens when we attempt to force a filler into the open cell as it often pops back up out of the cell because the filler is trying to compress the air in the cell. Note that all of this is highly dependent on cell size and viscosity of the finish or grain filler. Now cometh shellac.

The viscosity of shellac due to alcohol is extremely low and because of that it appears to me that the cell does not eject the shellac by capillary effect and therefore the cell appears to fill up with solids somewhat faster. Further, there is no bridging effect and the filling is COMPLETE and will greatly reduce the tendency for the finish to shrink over time , sink into the unfilled cell, and result in finish checking.

I think this explains why I've had so little success with water base fillers ( and others report the same). I'm not suggesting that thickened shellac will work well on grain porous woods like oak or ash but it may well be worth a try on the likes of walnut. Next up I will try cocobolo which is highly variable as to cell size, often being quite large and deep.

Does any of this make sense to you?

[Phil Thien]

Does any of this make sense to you?

Yep. I'd be interested in hearing whether this would work for oak. Would it be possible, when you're trying it on the cocobolo, to also try a small piece of oak?

[Harvey Pascoe]

Yep. I'd be interested in hearing whether this would work for oak. Would it be possible, when you're trying it on the cocobolo, to also try a small piece of oak?


I don't have any oak but I can try it with some ash.

[John TenEyck]

Most woods that are open pored will accept filler. Perhaps you haven't used an appropriate filler or technique if you haven't had success in the past. Mahogany, walnut, oak, etc. all fill pretty easily. Fine pored woods are a different story and I can see how shellac could work better with them. Surface tension, more than viscosity, might also play a role in whether or not one material wants to fill the pore or coalesce around the rim.

[Prashun Patel]

You're probably more of a scientist than I, but I've been able to fill grain with shellac, several kinds of varnish, and even oil/varnish/woodslurry.

I always assumed the reason shellac does not 'bleed back' is bkz it dries so darn quickly. Oil varnishes tend to bleed out of most woods because they remain wet long enough for the cells to spit. But shellac is like Medusa.

I did not think grain fill was a function of capilary action in the cells, but just a function of the craters in the surface of porous woods. You can really fill those craters with anything that's fine enough to fit inside them, even drywall compound or glue will 'work'.

Shellac will even work to completely fill the grain on highly porous woods like oak and ash. It just may take a while.

[Howard Acheson]

Here is an excellent article on the same subject by a very well respected woodworker/restorer.

http://www.hardwoodlumberandmore.com/Articles/ArticleViewPage/tabid/75/ArticleId/17/Grain-Filling-with-Shellac.aspx

[Harvey Pascoe]

Most woods that are open pored will accept filler. Perhaps you haven't used an appropriate filler or technique if you haven't had success in the past. Mahogany, walnut, oak, etc. all fill pretty easily. Fine pored woods are a different story and I can see how shellac could work better with them. Surface tension, more than viscosity, might also play a role in whether or not one material wants to fill the pore or coalesce around the rim.

Sure, pigmented filler stains work just fine but we were talking about gain filling with transparent fillers. I've sanded varnish and oil into the wood. Yuck, I didn't like the result.

[John TenEyck]

Sure, pigmented filler stains work just fine but we were talking about gain filling with transparent fillers. I've sanded varnish and oil into the wood. Yuck, I didn't like the result.


In addition to pigmented fillers, you can buy transparent paste fillers - I think they are silica based. In any case, they do exist, and are an alternative to the shellac method.

[Harvey Pascoe]

I finished up the India rose wood grain filling today, 4 apps of 1:3 shellac/alcohol and then gave it a shot of varnish. Near perfect. I also tried some quarter sawn ash, also 4 apps of same. Not completely filled but looks pretty good with one shot of varnish. Really needs two more shellac to do the job. Yeah, Phil, it works fine.

Filling and sanding is fast and easy, none of that malarkey of using a squeege across the grain and making a big mess. Plus, if you want to use it for color change, you can do that too. Going darker, not lighter. I did this on unassembled parts for a box which was nice in that it prevented the usual problem of unseen glue spotting.

How long did the filling take? Did it in stages while doing other things but I'd say not more than twenty minutes total, excluding mixing and clean up.

[Scott Holmes]

The author of this article is the guy I call when I run into trouble. Steve is a friend and a FINISHING GURU.

[Harvey Pascoe]

Just a side note here, going 1:3 on the shellac ratio poses a much longer delay in drying unless you have excellent drying conditions like putting the work out in hot sun, so I kicked it back to 1:4 and that brought dry time down to about 15 minutes. In the shop w/o sunlight, it was more like an hour, which defeats the purpose of speed.

[Howard Acheson]

Just a side note here, going 1:3 on the shellac ratio poses a much longer delay in drying unless you have excellent drying conditions like putting the work out in hot sun, so I kicked it back to 1:4 and that brought dry time down to about 15 minutes. In the shop w/o sunlight, it was more like an hour, which defeats the purpose of speed.

Putting it out in the sun probably had little to do with the speed of "drying". Shellac dries as the alcohol evaporates. Temperature or sunlight has little to do with it. But, putting it out doors probably exposed it to some sort of breeze. Air movement will accelerate the evaporation process. But, so would placing a fan to create air movement over the panel.

[Harvey Pascoe]

Yeah, there was a good breeze but I also have ceiling fans in the shop and that didn't seem to help much. All I can say is that the sun appeared to speed it up, but there is also the risk of it getting too hot and blistering, that happens occasionally when I'm not paying attention. The solvent then gassifies too fast and does not escape thru the outer film of dried finish of any kind.

[Prashun Patel]

Sunlight has nothing to do with evaporation. Sun heat does. So putting it outside in the hot sun will certainly speed the evaporation. However, it will (and I say this from modest experience) heat the surface most, which will cause premature drying of the top layer, which can impede the underlying finish from drying efficiently. This may cause subsequent coats to remain soft or the overall surface to remain soft.

Even shellac may appear to be dry, but should really be given good time to dry thru and thru. When I'm applying shellac, I only do several coats within the hour if they are very thin cuts. But if yr schedule works for you, power to you!

[Anne Schmidt]

Thanks all . . . timely subject as I am NOW trying to fill oak with water-based paste filler(famowood) and not liking these dark spots or the length of time it took to pigment it to the color I wanted, esp. given how it changes colors both after it drys and after it's coated!!! (shellac method makes color matching unnecessary.

So, I may try this shellac method(I love shellac).

Note on surface tension: alcohol does seem to relax surface tension; I have noticed that when just a couple of drops of alcohol are added to a water-clogged ear, the whole shebang---water plus alcohol drops right out. Thanks for bringing this concept into the wood finsihing world.


Surface tension, more than viscosity, might also play a role in whether or not one material wants to fill the pore or coalesce around the rim

Anne Schmidt

[Harvey Pascoe]

However, it will (and I say this from modest experience) heat the surface most, which will cause premature drying of the top layer, which can impede the underlying finish from drying efficiently. This may cause subsequent coats to remain soft or the overall surface to remain soft.

Even shellac may appear to be dry, but should really be given good time to dry thru and thru. When I'm applying shellac, I only do several coats within the hour if they are very thin cuts. But if yr schedule works for you, power to you!

Yes I have heard many people say this and it is certainly true for any finish that relies on evaporation like shellac. But for chemical cures like varnish, it is less true. Obviously any fast build finish is going to result in a longer cure and may result in surface finish checking. I've made that mistake with varnish. As I mentioned, I did have trouble with shellac drying at 1:3 but by extending to 1:4 it went ok. You quickly get the message by how well it sands - if your paper clogs up, its not dry! Applying more than one coat of shellac without sanding between makes it even worse.

[Stewie Simpson]

Yes I have heard many people say this and it is certainly true for any finish that relies on evaporation like shellac. But for chemical cures like varnish, it is less true. Obviously any fast build finish is going to result in a longer cure and may result in surface finish checking. I've made that mistake with varnish. As I mentioned, I did have trouble with shellac drying at 1:3 but by extending to 1:4 it went ok. You quickly get the message by how well it sands - if your paper clogs up, its not dry! Applying more than one coat of shellac without sanding between makes it even worse.

I agree with Harvey. 1 coat between sandings is a much better practice. Treat the shellac as a grain filler and wet sand back to surface wood with 220 and 400.

[Harvey Pascoe]

Sheesh, this is amazing. At first I though I was the only one who stayed home for the holiday but then I noted that we got 749 people online to this forum and almost no posts! Just readers I guess. Nobody have any dumb questions?

[Jack Clark]

Nobody have any dumb questions?

Okay, I'll bite. :o

Stewie, what are you using for a lubricant when you wet sand shellac?

[Kent A Bathurst]

. Nobody have any dumb questions?

Not me, but I'm always happy to take the other side - ask an insightful question, and I'll give you a dumb answer.

[Prashun Patel]

"But for chemical cures like varnish, it is less true"

Some varnishes rely on oxygen to cure. Once a skin forms, it blocks the oxygen.

"[shellac]: You quickly get the message by how well it sands - if your paper clogs up, its not dry!"

Not trying to be difficult, but even if it sands ok, applying too many coats too quickly and then heating the surface can cause a shellacked surface to blister. It's happened to me.

[Stewie Simpson]

Okay, I'll bite. :o

Stewie, what are you using for a lubricant when you wet sand shellac?
Hi Jack. I find water is a good enough lubricant to use. I keep a bowl of it handy to keep strips of wet & dry paper soaking ready to use as required. Hope it helps.

Stewie.

[Harvey Pascoe]

In addition to pigmented fillers, you can buy transparent paste fillers - I think they are silica based. In any case, they do exist, and are an alternative to the shellac method.

I've been looking for that but haven't found anything but water based. Do you know of any brand names?

[Harvey Pascoe]

Not trying to be difficult, but even if it sands ok, applying too many coats too quickly and then heating the surface can cause a shellacked surface to blister. It's happened to me.

Sure will and I think I mentioned that earlier. Got to be careful about that. However, I got away with that today when I forgot and left the shellacked filled piece I just shot with varnish out in the sun for hours.

[Peter Clark]

Something I have had good results with is leaving the sanding dust (finish only) in the pours and using a thinner finish to remelt the sanding dust on subsequent coats. Seems to fill the pours faster....

[Harvey Pascoe]

Something I have had good results with is leaving the sanding dust (finish only) in the pours and using a thinner finish to remelt the sanding dust on subsequent coats. Seems to fill the pours faster....

I've done that and it seems to me it leaves it with sort of a muddy appearance and reduces the prismatic effect (chatoyance) of fine woods. Now that I've finished the India rosewood box grain filled with shellac, I'm not happy with it. Not nearly as nice as a built up varnish finish. The crispness of the wood grain is lost. Maybe that is because my shellac is too dark so I'll try it again later with ultra blonde.

Here is what truly fine varnish finish can look like. This is on teak a very grain porous wood with no fillers used, strictly a built up finish using Interlux High Build. You can imagine how many coats that was! That was one of the most perfect finishes I've ever seen, and on a vertical surface no less. I took that photo and it is every bit as good as it looks.

[Scott Holmes]

Harvey,

If your shellac looks muddy then you left sanding dust in the pores. I have found that the best way to fill with shellac (I use super blonde) is to apply 2 or 3 heavy coats a few hours apart. Then I let it dry for a day or two. Scrap or sand it back to the bare wood leaving the shellac in the pores only.

FYI - wet sanding between coats can leave sanding slurry in the pores that will NOT alwaysdisappear when the next coat of finish is applied. Wet sanding is for rubbing out finishes not for between coat flattening.

[Prashun Patel]

I've been doing some experimenting with wetsanding varnish in between coats. I've been using this technique lately, and a recent article in FWW by Michael Pekovitch(sp?) uses a wetstanding technique after the sealing coat is complete.

I've found that wetsanding finish with 400 or 600 grit sandpaper leaves no noticeable muddiness on walnut or cherry. Wetsanding at higher grits CAN leave swirls and streaks. I wouldn't call this muddiness, but it does appear that fine slurry is trapped and not easily removed. I'm guessing. You can mitigate this by buffing vigorously. All this applies to oil varnish and wiping varnish finishes.

[Harvey Pascoe]

Thanks for that, but no way would I wet sand. For one thing, I'm using thin wood that is a veneer laminate and it would warp. Could be that I didn't get all the dust out and I definitely din't get down to bare wood.I thought the shellac might give the wood a warmer glow; it didn't. My super blonde should arrive today and I'll run some tests with it and see how that goes.

I'm not saying the results were bad, its just that when I put the shellac-filled piece next to one that wasn't, there is a very noticeable difference apparent when both are seen in direct sunlight. In artificial light, it hardly shows. In theory, there should be no difference if the tone of the shellac is the same or less than that of the varnish.

[Scott Holmes]

I have a sample piece that I show in my finishing classes; the shellac filled side blows the filler side away as far as clarity is involved. Are you using de-waxed shellac? You should be using dewaxed as a filler.

[Harvey Pascoe]

I was using dewaxed orange shellac, or so they say, but I've no way of knowing if true. I just got my super blonde and now see why I had a problem: the blonde is very clear whereas the orange is opaque and muddy looking, even when freshly mixed. On a test piece the blonde produced no color change other than the normal wetting effect.

[Harvey Pascoe]

As a follow up to this thread, I just finished a box top of maple burl and African blackwood with four coats of super blonde and was surprised to see it turn out lighter than expected, lighter than if I had just layed down the varnish first. The nice thing was that with the shellac, the burl didn't absorb varnish like a sponge and I should be able to reduce the finish from 5-6 coats to three, so there is a big time savings here.

[Scott Holmes]

If your orange shellac was not optically clean then the wax has not been removed.

Shellac is an excellent sealer. Don't get carried away with the shellac; you can apply it thick to fill the grain, because you are sanding/scraping most of it away after it dries.

For a seal coat just 1 or 2 light coats; too thick and you will have problems down the road when the shellac wants to alligator (crack).

[Harvey Pascoe]

If your orange shellac was not optically clean then the wax has not been removed.

Shellac is an excellent sealer. Don't get carried away with the shellac; you can apply it thick to fill the grain, because you are sanding/scraping most of it away after it dries.

For a seal coat just 1 or 2 light coats; too thick and you will have problems down the road when the shellac wants to alligator (crack).

Oh, really? That's good advice because that is exactly what I was doing, using around 4 coats under varnish! When I see real old antiques and they have that alligatored finish, is that shellac? Just for grins I finished the insides of a box with rubbed out shellac. Very nice finish but is that going to be a problem later?

No, Scott the orange shellac was not optically clear after mixing. Very cloudy in fact. Thanks much.

[Scott Holmes]

Oh, really? That's good advice because that is exactly what I was doing, using around 4 coats under varnish! When I see real old antiques and they have that alligatored finish, is that shellac? Just for grins I finished the insides of a box with rubbed out shellac. Very nice finish but is that going to be a problem later?

No, Scott the orange shellac was not optically clear after mixing. Very cloudy in fact. Thanks much.

Harvey,

Old shellac that has an alligator look... First, a very thorough cleaning, then brush with denatured alcohol to get the shellac to reflow and level out. It will take several brushings. Padding is another option. There is no need for more shellac there is already too much.

Bonus: You are not removing the original finish...

[Harvey Pascoe]

Hmm, this raises an interesting question. Alligatoring or checking so far as I know is caused by what I know as "post cure", which is to say that the finish continues to cure over years and shrinks. very old varnish will do that even with only interior exposure. Could this be due to exposure to various environmental contaminates, or is the finish continuing to give off volatiles or what? I have a hard time with the thought that shellac continues to cure, so what would cause the checking?

Or could it be that the method of applying the finish of these production goods was designed for speed and not durability by laying on too many coats, too fast?

[Scott Holmes]

My opinion is that the shellac is too thick and will alligator over time. Shellac does not cure. It dries. Re-introduce the solvent (DN alcohol) it re-dissolves.

The prefect shellac finish: the thinnest possible film finish that is flawless.

[Howard Acheson]

>>>> Alligatoring or checking so far as I know is caused by what I know as "post cure", which is to say that the finish continues to cure over years and shrinks

One of the biggest reasons for shellac alligatoring is longtime seasonal expansion/contraction of the wood substrate. Shellac is a very inflexible material. When applied too thickly, it will alligator in a couple of years. The thicker the coat, the more likely it will alligator. When applied thinly, it can alligator with enough time.

[Peter Clark]

My opinion is that the shellac is too thick and will alligator over time. Shellac does not cure. It dries. Re-introduce the solvent (DN alcohol) it re-dissolves.

The prefect shellac finish: the thinnest possible film finish that is flawless.

Lacquer is very similar- To thick, It will crack because it doesn't move with the wood underneath the finish.

[Joel Wesseling]

The finish is ejected from the exposed cell and mounds up along the upper edges of the cellHarvey and others, I need your help please.

I've been trying to figure out grain filling for some time now and it's been a challenge

Veneered Mahogany speaker cabinets: cant seem to fill the grain after about 10 coats of Target grain filler an another ten coats of super blonde shellac dissolved it Iso

Is the filler being ejected? Maybe

I'm using 1lb cut of shellac.. Maybe should be thicker?

Sanding after 3 or 4 coats

Just ordered 2 part epoxy filler that I will try on next cabinets. Noticed some Luthiers do it this way

Thanks, Joel

[Scott Holmes]

Joel,

10 coats of filler... How are you applying it?

When I fill with shellac I use a 2-3# cut and give it a coat or two then sand it back to bare wood leaving the shellac in the pores only.

1# cut is reallly thin it may be pulling the other coats out.

[Prashun Patel]

Also, how are you applying the grain filler? Are you letting it set up properly before buffing? For the shellac, since yr going to sand back, you can use a thick cut - 2-3# and you don't have to be so neat about it (except for the final coat).

[Harvey Pascoe]

Echo - ten coats? I recently did a test with quarter sawn ash and got complete fill with 6 coats mixed 1:4 by weight and I'm sure they were not completely dry between coats because I did this fast.

FYI, Epoxy is hideously toxic and you can develop a terrible allergy to the stuff, breaking out in terrible rashes that itch for weeks so bad it keeps you awake at night. After using the stuff for years, today I can't even get near epoxy. The dust will also wreck your sinuses. Sanding the stuff makes it that much worse when the fine dust goes all over you.

[Scott Holmes]

Harvey,

What system are you using for your shellac measurements?

I've see shellac measured in pounds of dry flakes per gallon or alcohol for many years. e.g. 1# cut, 2# cut, etc..

Ratios 1::4 or the like don't fit in that scope...

[Joel Wesseling]

I was wondering about the toxicity of epoxy filler. Really love shellac and want to figure it all out.. $50 for this epoxy too

I'm Padding it on in lines. builds up on surface with no problem

so I should weight the alcahol and shellac (ie)100grams of shellac to 400grams of alcaho. I'll see if this compares to a 3# cut.
I'll try this because I love shellac

I'll also hit you up later to about getting nice final coats by hand without spraying

Joel

[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.