First off, my name is Mark and I am new here. I am not a luthier, I am just a guy trying to pick up some skills and hope to be able to build guitars in the future. I wanted to start with some repairs since I am pretty familiar with setting up acoustic guitars and doing minor tasks like fret leveling, intonation, shaping new saddles and nuts. I picked up a Seagull SM12 on Ebay with a cracked bridge and the soundboard caving inward.
I know that a lot of 12 string guitars have problems with the string tension pulling the bridge area upward so I thought it was just the belly bulging up and I would be able to use a Bridge Doctor, but after receiving the guitar I noticed that the top is actually caving in more than I thought between the neck and bridge.
There is a hairline crack running from the bridge out toward the kerfing and bends up to the waist. At the waist the crack goes from a finish crack to a full open break in the top. See Image http://img809.imageshack.us/i/seagull3.jpg/
Looking down at the guitar in playing position the top dips from the fretboard to the bridge and then it slightly bulges up from the bridge to the tail. Here's an image http://img840.imageshack.us/i/seagull2.jpg/
Looking at the guitar from the tail to the headstock you can see the top is caved in at the waist. http://img827.imageshack.us/i/seagull1.jpg/
The top is also cracked at the glue joint all the way from the tail to the bottom of the soundhole. This crack moves when I push it so it's also a clean break al the way through.http://img684.imageshack.us/i/seagull4.jpg/
The bridge also has a crack forming all the way through the back 6 string holes. This looks like it could be glued and clamped.
Other than that the guitar is in pretty good condition. The neck is straight and strong, and the back and sides look great. I bought this guitar for cheap so I am not afraid to really dig into it. I am really looking for some experience. If you need any more information or pics from me please let me know.
My Seagull SM12 has the same cracks by the waist, and it was a cracked brace. It seems they have a love of cracking in half right next to where they are tucked in under the kerfing. I'd bet dollars to donuts you have similar problems. It looks almost like someone sat on it while it was in a chipboard case.
These tops are really soft wood - they crack pretty easily, and the braces seem to crack easily too. But they are fun guitars, easy on the hand, with a good tone that is hard to surpass without spending a boat lod more of money.
One thing you should know - the neck is bolted on. The bolt is hidden behind a sticker on the neck block. This is really good for you, because you can unbolt the neck after your repairs are done, and adjust the angle however you need to in order to compensate for your repairs.
After looking inside some more I did find a little bit of wiggling going on one of the X-braces (under the pickguard), so that will need to be glued. I also looked at the treble side tail end X brace and noticed that the brace doesn't even tuck into the kerfing (see image 1). I assume this is not normal.
I also took a couple more shots from the inside so you can see the crack from the inside (Images 2 & 3).
I am still not sure if gluing these few places will be able to flatten the top out. I was planning on gluing the crack on the top and adding 1 or 2 cleats under the crack near the waist.
Do you think the X-brace that does not go under the kerfing at the tail end needs to be removed and replaced?
Like I said, I am up for the challenge.
All in all it looks like whoever built it was having a bad brace day.The ends are too thin to hold up under the pressure of a 12'ver...at the kerfing.Hope this employee got better the second time .I know I did.Are you removing the top to
repair?It's easy to tell that if the brace had been extended that crack wouldn't have occured .Great investigative work! Send those shots to Seagull!
Maybe it's been badly repaired in between owners?
I thought about it last night and decided to replace the top. I really like the Bearclaw Sitka spruce top on my Taylor DN-4 so I might do that. I have never removed a top before so if you guys have any links to some good tutorials it would be much appreciated.
So far I found this one:
Thanks a lot for your advice!
If you are looking for a truly nice B.C TOP are good friend Brent Cole at Alaska Specialty woods has the best full figerd B.C I have ever bought. Good luck on your prodject .Bill.''''''''''''''''''''''''''''''