I'm using shellac on a workstation-desktop with a lot of surface area (~22 sq ft, in three separate sections). I'm new to shellac, but so far its working great, except that I'm getting some small ridges, pits, and tiny irregularities on each coat. Nothing huge, and I'm sanding them out easily enough.
But with that much surface area application and sanding between coats take a lot of time. I'm padding, and I've got 2 coats of very thin shellac (
Back your paper with something flat, and make just enough scratches to get rid of the worst. If you get big ridges, which 2# cut really won't produce except if you really screw up, or runs, which are possible wherever gravity is a factor, you may remove them with a fine scraper.
One nice thing about shellac is that it bonds chemically to the previous layer, which helps diminish the surfce irregularities. For final surface, why not give it a rub with 1# cut and just enough non-drying light oil (olive or grapeseed) to lube the passage of the pad. Makes a lovely gloss. Work like a French-polisher, circular motion, or figure 8 over a relatively small area at a time. Experiments, even if they go bad, are easily reversed, so have at it.
Try using a cabinet scraper between coats... I find it to be quicker and more accurate for knocking off the nibs and high spots.
Let's but it this way. If you don't get the flaws out before you apply the next coat when are you going to get them out, after they are buried under two or three more coats?
Think about it this way. You go out to your back yard and dig a hole. You then try to fill the hole by covering the whole back yard with layers of dirt until the whole yard is level. Eventually, you'll either get it even or you'll have to start scraping off layers you've added because you've reached the second floor of the house.
Just how much sanding a light sanding is depends on how good you laid on the coat.
Hi, JBB,
Last post says it all. The ultimate objective with shellac (or any high finish, I suppose) is to fill the pores - the valleys. However in doing that you're building up the hills ( the ridges, brushmarks etc) at the same time, so you need to knock down the hills between coats, while leaving the valleys full. The only other thing that I'd add to Mike's input is that shellac shrinks a *whole* lot as it dries, as anyone who has ever tried to fill in a scratch using shellac and an artist's brush will testify, so it will take a long time to build those pores up to grade. Many people avoid this hassle by using a grain-filler before shellacking/french polishing.
Cheers
Frank
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