I have a 1970s Epiphone flat top guitar that has been my main performance instrument for a couple of years - it has a great sweet sound and a great neck. A few months ago the action started changing and I realized that he neck angle was low. It has a bolt on neck, so I was able to shim the neck, and it played great for a while, until I tried medium gauge strings, and it started getting hard to play. I reshimmed the neck to give it a 0.4 degree neck angle and it was great - this time for a week. Then it got even worse, and I noticed that the top of the sound hole was warped down. I removed the strings and hung it overnight and it is back to norm and the neck angle looks perfect.
On the inside I can see that the top brace on the treble side is separating from the top of the guitar. I am concerned that the neck block may be loose.
How can I check the neck block? What is the best way to to re-glue the block and brace without removing the top? Should I remove the entire brace before re-gluing? Or can I try injecting glue into the space? After I repair would it be best to move back to light strings? Or can I still use medium?
In the second picture there is tiny bit of bulge over where the brace has separated from the top.
Sounds like an Epiphone ft-130. (can't open your huge photos on dial connection)
Laminated top. I have 2 of them, found them both sitting on the curb for the trash. One has a horrible replaced top and the other has the worst case of what you seem to have, with the neck cavity block being loose from everything except the back of the body. Factory glue sqeeze-out around that block is minimal, whitish in color and quite crusty.
I eventually want to fix mine up and have been wondering the best way to go about it. Perhaps peel away binding at the back the body and getting a fine razor saw to seperate the block from the back. I mean, I'm leaning toward the idea that it would be best to get all that crappy factory glue off the wood surfaces before re-gluing with a better glue.