Friday, 13 March 2009

Repairing a hole in an acoustic side

I have a lot of tools. There are so many different jobs I do on guitars I need a lot of tools. Most I buy, many I have to modify and a few I make.

This little clamp I made for a specific job, it doesn't get a lot of use but when I need it it's the only thing that will do.

Its made from a small piece of Australian Blackwood that I had around the workshop and an old kluson style guitar tuner. I like using guitar parts to make tools - it feels right that old guitar bits can help fix damaged guitars. A bit like donating your organs.

This guitar is unusual - it was hand made in London by a small maker who only ever made a few instruments. It is made entirely from recycled wood. It has the most balanced, lively and sensitive sound i have ever heard from a guitar.

It was brought to the workshop by its very proud owner who is clearly deeply in love with his guitar

It needed a re-fret, a repair on a minor split in the top and a hole in the side - which is where the little clamp comes in.

The back and sides of this guitar are made of solid walnut. Solid wood has a much better resonance than ply but isn't as strong and breaks much more easily.

One small piece of wood was still hanging on to the damaged area and I found the other pieces inside the instrument. I decided to strengthen the area by putting a patch on the inside. I made this patch from koa simply because its a strong hardwood and I happened to have a suitable piece in the workshop from an old ukulele top - another example of organ donation.

I removed the piece that was still attached with tweezers and glued it to the inside of the koa patch. This piece of the side covers about 2/3 of the hole. I drilled a 1mm hole in the koa just above the piece of side and passed an old guitar string through it (recycling again). This way I can align the splintered piece of side and keep it flush to the side of the body as well as attach the patch all in one process.

Its then a case of applying the glue and fitting the patch. The string passes through the hole in the post of the tuner and I can tighten it up.

Once the glue has dried the clamp is removed and the remaining splinters are glued in place like a jigsaw. The patch gives them something solid to be glued to. Then its a case of touching up the finish and the job's done.

I was sorry to see this guitar go - I cannot remember playing a better sounding guitar. I got Bill in from next door to have a listen, he's an experienced sound engineer and really knows guitars.

He didn't want to put it down either.


Feel free to contact me about repair work (if you are in NZ). I only check emails weekly so the workshop phone is always the best 09 307 6501.

Workshop Hours

Mon……. 8-6
Tues……. 8-6
Wed…….. Closed
Thurs …..8-6
Fri ……….8-6
Sat/Sun ..Closed

Mr Glyn’s Guitars

  21a Khyber Pass Road
New Zealand
09 307 6501, 021 912678


  1. hi glyn
    great idea, very helpfull!


  2. Hi Glyn,
    This is Tim Hill from London, and that's one of the guitars that I built !
    I can't remember the number but it should be on a label inside. i certainly recognise the grain and pattern in the Walnut, you spend so long looking at the wood as you make it that you never forget !
    Many thanks for your kind comments about the guitar, and I'm glad to hear its still lovingly looked after !
    I only ever built 9 acoustics and 1 electric bass. I now design HiFi, so still connected with music

    Many thanks

  3. Hi Tim,
    great to hear from you. The guitar is still with its original owner and he's madly in love with it. There's a pig inlayed at the 12th fret position if that helps you remember.
    Its got heaps of wear - all from use and no sign of abuse. It was a joy working on such a lovely instrument - if you design hifi half as well...

  4. that is an incredibly smart little DIY tool! Do you have or could you make a blog entry that illustrates some of your other 'homebrewed' tools? I would love to get some ideas for my own workbench where I build electric guitars and guitar effect pedals.



  5. many thanks for sharing this great idea!

    I own a gorgeous 1967 Levin acoustic which my lovely teenaged Son accidentally swung into the sharp corner of a coffee table. Result: a large hole in the walnut side.

    I couldn't figure out a way of successfully repairing the hole myself so I took it to a professional guitar repairer. He couldn't convince me that he knew either (and was ludicrously expensive) so it has languished in it's case for over a year.

    Suddenly your brilliantly simple tool and technique has given me my next project!

    thanks again!