Repairing an ugly side gouge/hole?

[SincereCorgi]

Hi, I'm wary of even posting this since I know that people (very, very skilled people) might have strong opinions about there being a correct way of doing this, which mine probably wasn't. In other words, try not to be too mean.

Anyway, this relatively inexpensive classical guitar ($200) came into work that had taken a bad collision. The whole bridge had popped off and there was a dime-size gouge in the side which had lost some material but not enough to be a hole. So, I cleaned off and reglued the bridge, then used wood glue on my fingers from the inside to work the gouge back to flat and stabilize it, then mixed glue with colored sawdust and used that to fill the remaining indentation on the outside. The color match isn't perfect, but it's less ugly than a raw divot of splintery wood.

What would you have done differently, assuming you're trying to do this within the budget implied by a relatively inexpensive instrument?

[MikeEdgerton]

I always ask myself WWFFD? (What would Frank Ford Do?) I thought he had an article on this where he actually cut out a piece of the side and replaced it with a similar piece of wood. That doesn't really fit into the do it cheap method so I'd probably be doing what you're doing if I wasn't just using something like Bondo. Even Frank recommends that in certain circumstances.

[darylcrisp]

i would have considered enlargement of the gouge to a complete hole(with a neat shape or design) and tell the customer it is a custom sound port. It more than likely would have given the player a perceived increase in sound of the instrument.

d

[belbein]

strong opinions about ... dime-size gouge in the side which had lost some material but not enough to be a hole.

Little story. I was working on an acoustic bass guitar for my son. I had the top and sides assembled and was just about the put the back on. But--it was late and I was tired and I knew better than to do anything in that situation--I looked at the top braces and thought: gee, I can carve those down just a little more before I go to bed tonight and then put the back on tomorrow.

So I got me a rotary tool on the end of my drill and went at the braces. All of a sudden there was this tremendous BANG. I thought that something in the shop had exploded. I looked around and didn't see anything. But I saw this really weird effect of a spotlight of light on the inside of the top of the guitar. That's weird, because the work light was overhead, and the only place it could be coming from was ...

Oh sxxx. It had to be coming through the side. I looked at the side and there was this hole, about a 25c piece size. Not a clean hole, either. What had happened was that the rotary tool thingie had traumatically disintegrated and flew off the head of the shaft, through my thin piece of wood that made up the side. I immediately realized that it would have been unlikely that it would have only bulleted in one direction ... and sure enough, 180 degrees from that first hole was a second.

So my choices were to throw the whole damn guitar away (no way); put together a kind of crappy plug (ick); or figure something else out. What I did was to clean the hole until it was relativley even. Then I fit a piece of the same wood into that hole, teased out the remaining threads of wood to blend into the patch, did a sawdust filler, and backed it on the inside with a wooden bandage that was bent to almost the same shape as the side. Looked absolutely ... OK.

Not too different than what you did. Of course I'm not a luthier and not a professional and I just kind of make it up as I go, but there it is.

[Mark Gunter]

Burn-in. Quick, simple, very effective, and cheap (if you do this stuff all the time and have it at hand).



https://www.youtube.com/watch?v=x-d9btPTImI

I use Mohawk products rather than Behlen, and a butane knife rather than the electric as shown in the video. I believe the Behlen products are available at Stewmac.

[belbein]

Thanks, Mark. Great stuff.

[SincereCorgi]

Thanks everybody, Mark especially. That burn-in stuff is really interesting, I just don't know if I'd use it enough to justify getting it.

[Mark Gunter]

I understand. It’s a finisher’s thing, I’ve been doing it for about 30 years on furniture as well as guitars. It’s an ancient method, and used to be done with shop-made shellac sticks and knives heated over Bunson burners. I learned with the electric ovens shown in that really old video, then went with the electric knife, and finally with butane knives when they came out. It’s a useful skill, and the supplies last a long time, so quick, inexpensive repairs.