Removing Mystery-finish

[Xaromir]

Sorry for creating so many topics, it's my first project and i have to learn a lot.

Well i've tried to get the finish on my little parlor guitar off before, but sanding that by hand is really hard,

so i wanted to ask for alternatives.

I have no idea what it is, but i suspect it to be shellac, since it probably was the finish of choice at that time.

I got some in my nose and mouth when trying to sand it since i don't have a respirator,

it has a slightly sweet smell and taste to it.

I've also tried to get the bridge off, i did that with a iron and a e-string when i've done it on the fretboard,

but i thought i try a hot blade this time,

and i noticed the finish instantly started fizzing and sort of melting - a bit like cooking.

It get's white and dull when heat and liquids are introduced to it, i noticed that when getting off my fretboard.

What is it? And how do i get rid of it?

Edited April 24, 2010 by Xaromir

[Mender]

It's very likely it is shellac. Have you tried a varnish scraper? That would be my weapon of choice. Just make sure you scrape away from you so you don't swallow or inhale the stuff that comes off.

[Xaromir]

I have not tried a scarper, since i don't have one.

Maybe razorblades would also be ok?

Well... i have to wait till next month anyway if i have to buy something new for it.

There is just one thing i'm worried about:

Will i notice if i hit the wood? If it get's dusty, then i would not be able to see it,

that stuff sticks to everything, and it's hard to get rid of the dust, even by blowing.

Yes, shellac is a disgusting thing to swallow.

What is it made of again? Excrement of what? Well, what ever.

I would get a respirator, but my hardware store only got those closed ones that make you breath in what you just breathed out.

Can't wait to get really started, every time i look at it i plan something new,

i will maybe also rebuild the bride now, i think i can call it a rebuild now, rather than a restoration. >.<

[ihocky2]

Shellac is possible, but I've never had a hard time sanding shellac. Try taking a q-tip with alcohol on it and setting it on the finish for a minute or two. If it softens up it is shellac, if not do the same thing with lacquer thinner. If it softens it is lacquer, if not it is some other type of varnish probably. Try the alcohol first because it won't affect lacquer too much, but it'll soften shellac. Lacquer thinner will soften both though.

Either way, I would go at it with a heat stripping gun and a scraper of choice. Always works quick for me, and if you are carefull with the heat it'll be pretty clean when you're done.

[WezV]

yes, shellac is a disgusting thing to swallow.

What is it made of again? Excrement of what? Well, what ever.

shellac doesnt have much of a taste - although i am sure it would if you ate enough of it.... but its used commonly in the food industry as a glaze

its made from a resin excretion of the lac beetle. eat tree sap and crap a lot of it back out as raw shellac

my guess is that you dont have shellac if you get a strong taste just from a little sanding dust, but it could be mixed with other things as luthiers often had their own secret recipes

test as ihockey suggested

[Xaromir]

Alcohol actually dissolves it, less than 1 minute on the guitar i pulled off the little piece of cloth,

it gone all sticks and after it dried some seconds later i noticed that some layers of that stuff must have gone.

It actually tastes odd, but maybe it's just some stuff the guy added as you've said,

or the age, how ever, i prefer not to breath it, by now i got a proper respirator - i love that thing.

I will get that finish off as soon as i got that damned bridge off.

Still no idea how to do that, but i guess i just make a print of it with silicone and chisel it off,

don't want to ruin my top.

[ihocky2]

Don't let silicone anywhere near the body, unless you want fisheyes and craters all over your new finish. Silicone extremely hard to remove from the wood once it gets on their and wil make refinishing a nightmare.

[Xaromir]

Don't let silicone anywhere near the body, unless you want fisheyes and craters all over your new finish. Silicone extremely hard to remove from the wood once it gets on their and wil make refinishing a nightmare.

Great piece of information actually - i received that information before, but actually never thought about it again.

Good thing i'm such a lazy [insert profanity here] or i would have done quite some damage! >.<

I actually got it off by now, and started sanding yesterday,

i continued today, and i consider the top mostly done now, and started at the back.

Picture from Yesterday:

http://i394.photobucket.com/albums/pp26/Xa...r/parlor-2s.jpg

That shape is so beautiful feminine and elegant. <3 I love it.

Question:

There are spots of finish that i did not get off so far,

since it apparently gone a bit into the wood, can i leave that or will that leave very bad discoloration?

I don't know if i picked the same color as the person before but it looks close when the shellac is in it's bag.

(I picked super blond btw)

[ihocky2]

I'll let the question on the remainng bits of finish to someone with more experience on refinishing than I, especially on acoustics.