Monday, January 12, 2004

Mandolin #2: Finishing

Finishing was one of the main places I wanted to improve on my second mandolin attempt. On #1, I was not happy with the transition between colors in the burst (barely any). Using the alcohol dyes (in addition my little sealer mistep) just kinda saturated the wood and made everything brown. On #2, I really wanted a distinct burst with light orangy colors in the center and completely opaque brown/black around the edges. A few posts on the Mandolin Cafe builder's forum lead me to trying to spray pigmented lacquer to create the burst.

The Foundation of the Burst

As on #1, the first thing done was to apply an all over coat of lemon yellow using an alcohol dye. I then sprayed a coat of sealer. BTW, on #1 I used the Stew Mac spray lacquer in a can. Because I wanted to be able to add pigment to the lacquer on #2, I used the "Behlen Nitrocellulose Stringed Instrument Lacquer" from Stew Mac and disposable (sorry, Earth) Preval spray canisters.

Masking for colored lacquer Front with stain Back with stain

After the sealer coat, I started spraying the burst. The challenge on this process was not trying to get things too dark too early. I started with a more reddish brown and tried to just lay a thin coat around the outside of the back and belly and on the neck and headstock. I then moved darker and darker and farther and farther towards the rim.

First dark coats scroll First dark coats Front with dark rim Back with dark rim

Well, this is where my $3.95 spray system kinda failed me and I found that it was difficult to be precise with the spray. Also, if I wasn't careful, larger spray "dots" would sputter out onto to the mandolin. I did find however that lacquer thinner does its job and was able to wipe away areas of the darker lacquer. I developed a method of what I was calling "trench polish" in which I used a cloth with thinner to try to blend from the dark areas into the burst. I wouldn't really recommend this method but in general I was able to get the colors if not the exact transition I wanted.


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