How best to remove finish?

[Hanzalot]

Hi

I have this old Harmony terz guitar where the finish is really bad--it seems to have been refinished once and then left in the sun to dry. So I was thinking about removing the finish to just have it as bare wood since the bad finish really bugs me.

How do I do it best, sander or heat gun or something else? As you can see in the photos in the link below it looks like there is a pretty thick layer of paint in some places...

https://imgur.com/a/rRYDbPE

Thanks for your help!
Hans

[runamuck]

Probably lacquer thinner will work - or paint stripper if it's not lacquer. Don't use a heat gun on an acoustic guitar as there's a chance you'll crack the solid wood as it dries out too quickly.

[mirwa]

First, make sure the wood is thick enough to survive a finish removal, measure various locations, most methods will involve some form of sanding of the wood itself, the only method that does not is plastic media blasting

I have knocked back easily 50 plus resprays over the years due to the wood being IMO to thin.

Steve

[Hanzalot]

Originally Posted by mirwa

First, make sure the wood is thick enough to survive a finish removal, measure various locations, most methods will involve some form of sanding of the wood itself, the only method that does not is plastic media blasting

I have knocked back easily 50 plus resprays over the years due to the wood being IMO to thin.

Steve

Thanks Steve - how thick should it be?

And @runamuck - thanks, paint stripper sounds like a great idea. Does this look like the right stuff? https://www.google.com/search?q=lak+...EW&pie=plaji-i

Hans

[JonWint]

I prefer to remove by dissolution without removing wood. This guitar had a coat of red-tint lacquer over the original lacquer.

I removed it with lacquer thinner and paper towels. Took 2 to 3 hours. My amateur hours are free. Sanded with 400 grit for less than 5 minutes. Insignificant wood disturbance.

[IMG][/IMG]

[maxtheaxe]

Originally Posted by JonWint

I prefer to remove by dissolution without removing wood. This guitar had a coat of red-tint lacquer over the original lacquer.

I removed it with lacquer thinner and paper towels. Took 2 to 3 hours. My amateur hours are free. Sanded with 400 grit for less than 5 minutes. Insignificant wood disturbance.

[IMG][/IMG]

That looks great...the very thing I've been looking for, but want to verify...the lacquer thinner will soften & wipe away finish that has hardened? Is there any necessity to somehow neutralize any thinner/residue left in the wood before refinishing, or does the follow-up sanding accomplish this? Once stripped, I plan to put on a sealer coat of shellac prior to spraying with nitro-c.

I've been planning something like this on a late 70's MIJ Martin copy (Aria PW-70/Matsumotu). Your method seems to be the best option I've seen, short of putting ungodly hours worth of sanding into it and risking taking it too far.

[runamuck]

Originally Posted by maxtheaxe

That looks great...the very thing I've been looking for, but want to verify...the lacquer thinner will soften & wipe away finish that has hardened? Is there any necessity to somehow neutralize any thinner/residue left in the wood before refinishing, or does the follow-up sanding accomplish this? Once stripped, I plan to put on a sealer coat of shellac prior to spraying with nitro-c.

I've been planning something like this on a late 70's MIJ Martin copy (Aria PW-70/Matsumotu). Your method seems to be the best option I've seen, short of putting ungodly hours worth of sanding into it and risking taking it too far.

If it's lacquer, lacquer thinner will soften and remove it. I'd recommend using thinner along with steel wool. Steel wool will catch the old finish better than paper towels. You need to work quickly because lac. thinner evaporates fast. Because of that and the fumes, I'd suggest a paint stripper instead. You can get paint strippers at the hardware store and my experience is that the more expansive ones work better. If you do use a stripper, neutralize the wood with lacquer thinner or, better yet naptha when you're done

[JonWint]

It's a 1927 Martin. Lacquer dissolves. This was at least twice as thick as factory. Found that laying on a towel and saturating with thinner softened easier than excessive rubbing from dry.

There is no residue. Thinner flashes off. I also removed most of the filler in the process.

Final finish is French-polished platina shellac with no filler. Second pic is off-the-pad finish; no compound/abrasive polishing. I realize that the finish is inauthentic. Next owner is welcome to change it if they desire.

[IMG][/IMG]

[IMG][/IMG]

[Hanzalot]

Originally Posted by JonWint

It's a 1927 Martin. Lacquer dissolves. This was at least twice as thick as factory. Found that laying on a towel and saturating with thinner softened easier than excessive rubbing from dry.

There is no residue. Thinner flashes off. I also removed most of the filler in the process.

Final finish is French-polished platina shellac with no filler. Second pic is off-the-pad finish; no compound/abrasive polishing. I realize that the finish is inauthentic. Next owner is welcome to change it if they desire.

[IMG][/IMG]

[IMG][/IMG]

That looks amazing! Do you have a link to the specific paint thinner and finish you used?

Thanks
Hans

[JonWint]

Originally Posted by Hanzalot

That looks amazing! Do you have a link to the specific paint thinner and finish you used?

Thanks
Hans

Whatever generic lacquer thinner your local hardware store sells.

Shellac is from flakes. Platina is the color. I buy from:

https://www.shellacshack.com/

You should look for a more local supplier.