Bubbles and Blisters

[Flatpick]

How could/would you attack a problem like this? This joint appears to be solid. In all in the finish.

Flatpick

[Flatpick]

Another pic...

[Flatpick]

Also this....

[Ken]

It looks like an adhesion problem with the lacquer. For whatever reason, it is not sticking to the wood. Could be some aspect of surface preparation, incompatibility with the stain, or the sealer itself. Over the years I've had adhesion problems a couple times and in my very limited experience I know of no way to fix it short of stripping and refinishing the whole instrument. If it was just one small spot maybe there's a way, but from the look of your mandolin, and in my experience it is never just one small spot. I am now using shellac as a sealer, which adheres very well to try to avoid this problem. I'm looking forward to seeing what other responses you get, especially if somebody does have a fix for this.
Ken.

[jim simpson]

Flatpick,
Just curious as to the make of your mandolin?

[Michael Lewis]

As Ken said, there may well be something preventing the finish from gripping, but the finish is too thick which causes problems. It could be touched up in just the spots that are effected. The loose finish along side the neck could possibly be from an impact, but it needs closer inspection as it is indicative of some movement between parts at that joint.

[Flatpick]

The Mandolin is a 91 Gibson F5L. It had been played alot in southern hot climates at Festivals. Alot of outdoor use. It is a great sounding Mandolin it just has finish problems that I believe are due to heat and humidity. I'm not looking to make it perfect, just more presentable and not so distasteful looking.

Flatpick

[Big Joe]

The way it looks it could easily be a moisture problems. It could well have been something wet or damp was left in contact with the instrument long enough to cause the problem. While there could be several causes, this seems to be the most likely from what the pictures show. The only real way to tell is to see the instrument. Whether it can be repaired or needs to be refinished depends upon how perfect you want it and how far the damage is that does not show in the picture. Thank you.

[Darryl Wolfe]

"I'm not looking to make it perfect, just more presentable and not so distasteful looking."

I think this would be relatively easy to accomplish..just flake it off, blend a bit a respray. If it happens more later so what

[Flatpick]

All great suggestions. Thanks for the replys. If a refinish is in order I had thought about sending to Gibson and have the Laquer stripped off and Varnish applied.
What do you think Big Joe? Is this process quite expensive? How would it affect the Tone quality?

Flatpick

[Charlie Derrington]

Five will get you ten that it's a lot more complicated than it looks. Send it to us and we'll check it out. My guess is that it is a neck-joint failure that shows up as finish popping off around the joint.

The headstock is probably a finish only problem. Send it to us and we'll take care of both problems.

Charlie

[Flatpick]

Thanks Charlie:
What address would I send it to and what Department?

Flatpick

[Luthier Vandross]

Send it to me, and I won't make it black, with a dime sized oval of greenish yellow.

http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

M

[Gail Hester]

While I don’t have much experience with lacquer finishes on stringed instruments I do have experience lacquer finishing on lots of drum sets. I generally agree with everyone as to possible causes and in addition I have seen direct sunlight cause bubbles due to gassing. I have not seen humidity as a factor and living in the Pacific Northwest our drums occasional get wet hauling to and from gigs but then we don’t have high humidity and they don’t stay wet for very long. Its also been my experience that if there is going to be an adhesion problem due to contaminants or an incompatibility with the underlying finish it usually shows up as a result some stress to the finish otherwise it just doesn’t stick in the first place. I saw this problem at first when I screwed on the drum lug hardware to a newly lacquered finish and wham, bubble separation. I think Michael is right-on as to the most common cause of separation being lacquer that is too thick and movement or impact. Since this is reported as being a great sounding mandolin it’s probably not too thick everywhere but just built up in the heal area where it’s difficult to sand.

Going out on a thin limb as to my hair brain theory as to what’s going on with this mandolin. I may be reading too much into it but from just the photos it appears that this mandolin has been refretted at some point. Getting back to the impact, movement, thick lacquer causes, it appears that all of the problem areas are also places that would absorb the most impact/shock from hammering in frets during a fret job if proper precautions were not taken. Hmm…

It certainly can be touched up as suggested but if it sounds great now, varnish would be even better IMHO.

[Scotti Adams]

..while studying the pic of the neck joint more closely I detect that the binding has seperated or cracked on both sides of the heel...this idicates neck movement more than likely....Im goin with Charlie D on this one..

[Michael Lewis]

As the side bends up to the heel where the big blister is, it looks as though the side wood had been broken out and glued back in(about 4 times bigger than the blister). Gail may be correct about the stress damage during a refret job, but I think it has had more "stress" than rough treatment during a refret.