Shellac Smooth Application Problem

Re: Shellac Smooth Application Problem

Ed Mulligan, Cape Cod

>Sanford �

I can�t sand a single wash coat of shellac. It�s too thin.

Shellac will dissolve shellac but if your imperfections are dirt, sawdust etc they need to be removed before the shellac is applied or later after you�ve built up some thickness in the glaze. Your waterbase dye might be raising the grain in which case you�ll need to knock down the fuzz somehow. I raise the grain by dampening with water, then sanding before applying dye.

If you are getting brush marks etc you could try a shellac retarder to slow down drying. This should allow the shellac to flatten before it hardens.

Also, the shellac might need to be strained to remove crud.

Ed

Re: Shellac Smooth Application Problem

Wiley Horne

>Hi Sanford,

I wipe on, so can't help with the brushing. You're laying it on with the grain, right?

It kinda sounds like the shellac may be getting overworked, as you lay it on. Could it be that it's either going on too dry (not a wet enough brush or pad), or else that you're wiping over it and dragging the finish as it's drying?

It's usually warm and dry where I am (So. Cal.), and I find the best thing here is to use real light coats--1 lb. max. And lay it on fairly thick, though not running, in a single continuous pass down the board with the grain. And _never_ overwipe what I've laid down. Instead, go back to recharge the pad and keep moving. You can always come back with a second coat.

By the way, how picky are you? I find the shellac always sets up with some nibs. I only need to sand or scrape the final coat on flat areas, but I like to keep recesses and arises and other details cleaned up as I go. Lee Valley's very hard, very thin card scrapers are perfect for denibbing flat areas, so you don't have sanding grit proliferating around. BTW, those are fantastic scrapers for a lot of purposes--a most used tool.

Wiley

Re: Shellac Smooth Application Problem

Bob Hackett(Mainely,Bob)

>Does anybody else add afew drops of BLO when the going gets tough while padding it on?

MB

Re: Shellac Smooth Application Problem

William Duffield, on the Cohansey

>Wiley speaks of a retarder. You might try Behlen's Behcol instead of DNA. It uses isobutanol, instead of methanol, as a denaturing agent for the ethanol, because it evaporates more slowly, allowing the shellac more time to smooth by surface tension before it hardens.

Re: Shellac Smooth Application Problem

Frank D. in Montreal

>I like Behlen's more than other solvents because it's more forgiving. FYI, the LV shellac thinner is Behlen's with a LV label on top (I'm not sure they can ship it by air mail though, and Behlen's is probably easier to find in the states than in Canada). You can also try glycerine, a little water (less than 10% total), or balasam fir gum as retardants. They do make life easier. In the winter I also keep the shop cool when I have to apply shellac to large surfaces. 0�C (I forget what that is in Farenheit...32�?) is the best temp for easy application IME. Thin coats wiped on, thinned solution, as others have mentioned also help. Working as quickly as possible. Detail makes it hard to apply evenly, and it's almost impossible to rub down and even out if there is too much detail or too many inside corners. For assembled pieces with a lot of detail sometimes spraying is the only option, especially for darker shellacs (I don't spray). I usually try to get 3 coats on before rubbing down, but I'm no expert, it's just what works best for me. Rubbing down with sandpaper is, I was told and have found, best done without a sanding block, with sandpaper folded in 3 and slightly curved so your finger tips can apply pressure right where the nibs or fat edges are. With practice I'm better at applying shellac than I used to be, but as others have mentioned it's rarely perfect (the larger the piece the harder it is to apply); rubbing down, for me at least, has become as important as applying the shellac. By the time I get the last, very thin coat on (the "show coat"), I've usually managed to rub down the imperfections.

Just my experience as an amateur who loves shellac.

Oh yeah,

Frank D. in Montreal

>One more thing that helps me is rubbing out with 0000 steel wool before that final thin coat. This will blend in any ridges or bumps that are left over, making the transitions between uneven surfaces of finish less abrupt so they show less.

I think Ed very likely has the answer here

Wiley Horne

>when he talks about the water-based dye raising the grain, and what to do about it.

Wiley

Re: Shellac Smooth Application Problem

Sanford Levy

>Thanks guys. I will try all of the suggestions here, especially the retarder and trying behlens solvent instad of the hardware store variety. I do not have trouble with raised grain from the dye since I raise it and buff it off before applying the dye. The problem is not little dust nibs either. Its brush strokes and marks left over from the pad. I try to avoid overworking and just brush or pad on with a touch of overlap, bu t maybe that is the problem. Oh well. I will practice more. Ah, I should add it is mainly the very thin wash coats that I have a problem with. When I have used a thick coat, say, as a final finish, I can sand out any problems and then polish it up. But any inperfections in a thin wash coat are hard to get rid of. Sanford

A solution

bill tindall

>One solution is to apply many, like 10 or so, very thin coats, 0.5lb or less. Fortunately they dry quickly so it really doesn't take very long to do if the piece is small. After a few coats sand smooth and carry on. This is the technique I learned from David Finck and it has worked for me. Spraying a heavier mix also works well. I never was successful brushing 1 # or heavier material as it resulted in all the problems you describe.