What you don't want to happen

[Kevin in California]

I am recovering, but this is one of those ugly moments in finishing your guitar
I have made 15 guitars, 12 of those sprayed with nitro and this is the first time this has happened to me.
I always wet sand the finish prior to buffing. So on my recent build I am doing this. I am always careful on the peghead with those tuner holes present, to not get a bunch of water running down those holes. So again, I was careful. All looked awesome after sanding. The neck has sat a week since I did this wet sanding. Nice and flat up to 2000 grit. On to the buffing wheels. Using the IP Menzerna compound. After just a little bit of buffing, slight pressure, hardly any heat build up, I saw the dreaded lifting and spliting of the finish on the back side at 3 of the tuner holes.........EGAD!!!! I've never had it happen before. Panic at first. Then I calmed down, and addressed the problem. I sanded back down flat with 320 grit. I PROBABLY should have waited a day or two, but I started respraying the back side, 4 good coats. I will lightly DRY sand tonight and see how it looks. I think I will not wet sand this area again, and on future guitar builds. Not worth the risk. I always figure a little lacquer gets down in there and I would not have issues.....but not this time.
So anyone else have this happen.....I'm sure it has. How did you handle it.
I am also going to hand polish this area on this guitar and not put it on the buffer again so heat is not going to swell up inside again.....sure hope I've done it right.

[John Parchem]

I do not spray nitro but I had not even known this would be a problem. So, water in the tuning holes absorb under the finish and cause it to lift? It sounds like you have fixed. Depending how far the finish lifted on the back of the peghead, I might have wicked CA in given that the tuning machines cover quite a bit of the peghead back. I use Shellac a lot so I often wet sand with odorless mineral spirts. It works as a pretty good lubricant.

[Herman]

Yes Kevin, I too had this with an early guitar of mine. Nowadays I be sure to sand the headstock with, as little water as possible.
When I have cracks like that, I drop a bit of thinner in the gap and put a drop of laquer on top of that.
That fills the gap and adheres the finish again to the wood.
But let it rest for a few weeks. If you start too early, it will show.

Another time I made pictures of a finished hd28 outside, nice weather, but about freezing.
Without thinking, I took it back into the living room.
Next day the top finish was full of cracks around the bridge. Grrrr.
"Every mistake is a challenge". Ya, sure.
Herman