Steps for gloss finish

Discussion in 'Luthier's Corner' started by zapchris, Jun 30, 2005.

  1. I'm at the finishing stage of building my first bass and need advise on finishes. The body is 1/4" quilted maple, on 1/8" walnut, on 1-3/8" alder. I have decided to use alcohol-based aniline dye in two stages (dark coat, sand, light coat) to get depth in the finish. I tried a practice piece with the dye and 6 coats of shellac, followed by 300, 400, and 600 grit sandpaper, pumice, and finally rottenstone. The finish was beautiful - it looked about two inches deep. Unfortunately, two problems arose. First, the finish was soft enough to be marked by slight fingernail pressure - I admit to using very liberal coats of shellac, and maybe not allowing enough drying time. Second, after leaving the sample in my car on a hot summer day, the shellac over the walnut started to form small bubbles.

    My questions are:

    -Would thinner coats of shellac, and longer drying times remedy either of the aforementioned problems?

    -If not, would you recommend oils (Although, I have read that the slurry produced could bleed between the walnut and maple) or lacquer (water-based would be prefered, as I have heard it is a bit more forgiving, and I do not have spray equipment)?

    -What steps should I follow? Do I need sanding sealer and at what point do I apply it? Grain filler for the walnut? Is water-based lacquer compatible with alcohol dyes?

    Thanks in advance for any insight on my dilemma.

  2. Shellac, when cured completely, is supposed to be very hard. I don't think your shellac was cured deep down in the walnut. I think the heat caused some outgassing of the remaining solvent and that's what softened the shellac.

    Actually, thicker shellac can be used for pore filling. You pour some out and let it thicken then spread it like honey with a card or something. It won't take long for it to harden but I always like to wait longer. These types of finishes can't be rushed.

    I know that polyurethane can go over shellac but I don't know if anything else can.
  3. teej


    Aug 19, 2004
    Sheffield, AL 35660
    I just finished up that jazz project I've been working on.... I love this bass, but I'm a little disappointed at the finish. It didn't come out as smooth or glossy as I was hoping. Is there anyway to smooth the finish while building a deep gloss?

    (oh yeah... will poly go on acryllic lacquer without any problems?)