HTS Back Crack Repair

Back cracks in Acoustic guitars can be tricky to repair as you cannot apply a single clamp over the area.

This Martin guitar has sustained a small impact into the back, this has in turn split the back open, adjacent too the book matched original join, this walk through is on how I reglue the area and why I use the glues I use.

Time to repair, approx 3 hrs over 3days

With an internal light source we can see a large split.

After 2 days in the humidity controlled enviroment, the back has closed up really nicely

A typical throat clamp cannot access the back of the guitar

Titebond is awersome mstuff but no good for this job, titebond has a thing called creep factor, that is when a load is great enough the glue will stretch.

Example I can stretch a fraction this piece of dried titebond glue

Internally we are going to re-inforce the join with a traditional back cleat

With some masking tape and magnets, I can lay out a pattern showing the internal braces, by placing the magnet up to the brace inside.

Internal braces marked out and cleat trimmed to fit gaps.

Remove strings / pins and saddle for safe keeping.

Back view of this guitar.

Rehydrate the guitar, make sure the humidity is good/

One of the tools to do this job is a mini scissor jack, the end of the jack has a magnet fitted.