Gibson TG3: Loose Back Braces

Related Topics: | Body Cracks | Bridge Plate |


1. Another Installment of a Gibson TG3 Restoration. This repair description covers the repair of multiple back braces that came loose sometime during the 45 years since this early 1960's tenor guitar left the Gibson factory.	2. A Loose Brace is no laughing matter. Bracing is designed to help reinforce the plates (top and back) as they contend with the tension of the strings. Although loose back braces aren't as dangerous to a guitar as loose top braces, they will still cause structural problems if left unattended long enough.


3. Clamping the Outside of the Guitar is necessary to counter the force of the spreaders I'll be using inside the guitar to clamp down the braces.	4. Hot Hide Glue is my glue of choice for this job since it resists heat failure. I squirted the glue up against this brace using a pippette.


5. Working the Glue into the Open Glue Joint with a modified putty knife. I'm working quickly to ensure the glue doesn't start to gel before I clamp down the braces.	6. A Quick Clean Up with a paper towel held by the shop's forceps gets rid of the majority of the excess hide glue. The clock is ticking here since I only have about 15-20 seconds to clamp the loose braces before the hide glue looses its strong initial tack. It's okay if I can't quite make it because I can always flow some hot water into the joint to recharge the recently applied glue.


7. Clamping the Loose Brace with a small block of wood and a mini-spreader works really well. The force of this little spreader could damage the plates if I hadn't engaged the use of an outer clamp to counter- act the spreader's clamping pressure.	8. All Cleaned Up and Ready to Go, Almost... I'll go ahead and glue down the remaining loose back braces, then I'll show you how I make sure they stay put.


9. A Gap Between the Top of the Brace End and the Lining is what allowed these brace ends to come loose in the first place. When the top of the brace end fits snuggly against the notch in the lining it can not come loose. I'm not sure why the manufacturers have consistently overlooked this point throughout their histories...	10. Cleaning out the Notches in the Lining with a dental tool is necessary to get rid of any excess glue and accumulated gunk.


11. Fabricating a Mahogany Wedge. I'm tapering some mahogany shim stock with a chisel. After I've fabricated the wedge I'll dry fit it into the space between the lining and the brace end. If it doesn't quite fit I'll cut off a small amount from the tip of the wedge and dry fit it again. I'll repeat this process until I get a nice tight fit.	12. Gluing in the Wedge with hide glue. I pressed it in by hand, then seated it with the tip of a flat head screw driver. That's a pretty good fit.


13. Breaking the off the Excess Wedge. After the glue cured I simply pulled up on the protruding portion of the wedge with my index finger until the excess broke off. Since there is still a small amount protruding I'll have to break out the edged tools in order to help hide the repair.	14. Scoring the Excess Wedge with a violin maker's knife.


15. Trimming the Excess Wedge with a firmer chisel. I've worked the chisel in between the nub of excess wedge. Now I'll break it free at the score mark by using the chisel as a lever.	16. Cleaning up the Excess Hide Glue is no big deal since hide glue is water soluable. A q-tip dampened with warm water safely removes the glue with ease.


17. Here's an After Photo of the Wedge. The repair came out rather well: there is no more gap between the top of the brace end and the lining, also, the repair is noticeable only under close inspection. This means that the loose brace repair I've performed will stand the test of time.	18. The Brace After Water Clean Up.