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This guitar just came back yesterday for a Baggs Lyric install. It was about as simple as it gets and I had a chance to use my newly purchased end jack reamer. Nice.

Local Maple and Redwood that a friend cut from logs 20 years ago. It has an alcohol type burst. The fellow that owns it is about as happy as one could be with it and plays it every day. If only I knew what the heck I did
to make it sound so nice.




And then, as I'm about to wind down the strings I SEE THIS !


Note the finish delamination around every tuner washer. The finish is Mohawk nitro and I think it has a coat of vinyl sealer under it.

I'm wondering if anyone else has had this happen? I have a theory myself. I've had problems in the past with small delams on some of the hard edges. Bindings, headstock. They have happened from light impact in the final finishing. I leave instruments for at least a month to cure. Usually longer but I do most of my building in the winter months. The room where I leave them to cure is usually a little cool in the winter. Below 15 C or 60 F. I'm thinking that the finishes are are more prone to delamination (and of course other damage) in the fresher form.

Anyone care to comment? Need more heat during cure time possibly?

Cheers,
Danny

Hi Danny,

I use Mohawk and generally don't use vinyl sealer. A few years back I tried vinyl sealer under the nitro and ran into this same problem, where the finish would start to delaminate around the tuner washers or endpin jack. I can't be sure the vinyl sealer is to blame as many people use it successfully, but since I had no problems finishing without the sealer I stopped using it. Now I am either spraying the nitro onto bare wood or if I'm using Zpoxy as a filler I shot a coat of shellac before spraying the nitro.

As for fixing this, trying wicking thin CA under the part that is delaminating. Run a toothpick with thin CA on it around the edge of the tuning machine hole. I have found this to work very well for this problem. Also pay close attention not to over-tighten the the nuts on the tuning machines.

I can't comment on how the curing temperature effects how a finish delaminates, although I would think you should still be ok unless your curing temperature is a lot below 15C.

Josh

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Josh House

Canadian Luthier Supply
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How are you prepping between the vinyl and the nitro? Delamanation of coatings is often caused by something in the prep work. Assuming that the sealer and nitro are both Mohawk products and are recommended together we can pretty much rule out coating incompatibility.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks Josh. Wick CA! Never thought of that. I've wicked lacquer thinner with some success. I may have to give that a try............. carefully. I'll have to calm down from my usual "go into it with both guns blazing" approach.

Thanks Todd. I know you're a proponent of vinyl sealer. I think that's why I'm using the stuff in the first place. It does give a great base coat and there doesn't seem to be issues with the bond between the 2 products. Maybe I should quit sanding beyond 80 grit.


And yes, there's a good reason to use press in bushings for sure. The last one I did had Grover open backs. I liked the bushing but didn't care for the tuner. Funny, I've used them a couple of times on slot heads and was happy but the set I put on a solid peg head had more slop than I care to feel.

Hey Brian. I don't usually sand any wood beyond 220. I think I sanded the vinyl with 220 prior to shooting nitro. The head plate is Maccasser. I wonder if it has a high oil content? I should maybe quit using an impact gun to put the nuts on. I'm kidding of course but I do use a nut driver. I will most certainly go a little more gentle in the future.