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Discussion Starter #1
I remember seeing it in passing once but can't remember what it was... Stripped down a Yamaha once and under the paint that layer needed to be sanded off, chemicals wouldn't touch it, heat gun either.

Stripping down a Cort today, and wow that was a super thick layer, took literally hours with 60-grit onban orbital sander to get one side done.

Sadly, i was going to just sand a bit and repaint, but grain looked good through the layer but oncevthere was kinda blah....

What is that stuff? Polyurethane?

Trying to figure out what it is and how its on so thick so i can redo the front.

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Yes it’s polyurethane. A heat gun, scrappers and a lot of patience is probably the only way to remove it.
 

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Discussion Starter #3
I had that Yamaha with the same stuff on it... heat gun did nothing. Though this guitar a few spots are chipping off so maybe more luck.

When can you get poly that goes on 'that' thick? I have water based Minwax poly... would take 20 coats to get maybe half what's on the guitar.
 

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That's why poly shines so well. Multiple coats, light sanding in between. I watched a video the other day of a luthier putting on a poly finish and it took about a week to get the number of coats he required for the finish. You can only get about 2 coats a day with a 5 hour wait time. You can also mix oil based poly with Boiled linseed oil and or mineral spirits. (equal parts) First couple of coats 50/50 poly/mineral spirit so it goes on like water then after a few coats go to 50/50 poly/BLO.
 

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Discussion Starter #5
I've only finished the 1 guitar so far, but for that I used car paint mixed at NAPA/Ideal Supply and a 2K Clear from Max Spray. Ended up using the full can because only 48h to use it once the chemicals mixed. Sanded that guitar with 600, 800, 1000, 2000, 3000 and 5000, polishing paste med, fine and then the finishing cream.

That was one glossy guitar when it was done! :D

That said... I think you're talking about the wrong poly coat. I'm talking the one under the paint. I doubt they layered and sanded between layers for a week only to do a final spray with black enamel. Being as thick as it was, part of me wonders if it wasn't dipped in something. But, seriously, bewteen the wood and the black paint, that layer was more than 1/16" thick, borderline 1/8"... which also has me worried because if I decide to strip it instead, how would that effect the overall shape of the body. May not look as good.
 

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That first layer is probably mixed with mineral spirits so it gets soaked into the wood. Makes the poly super thin and then the minerals spirits evaporate. Unless it is actually a thick coat of some kind of wood filler
 
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