Dealing with worm damage on a new back plate

[Will Turner]

I started a new project that is using some 70+ year old maple from Germany.

while working on it, I have run into worm damage near the join.

Not sure the best technique to fix it.  It sang when I was testing it, so I am reluctant to toss it.

Suggestions?

Wood is not tanned, just very old.

 

 

[Colleen McTigue]

To my untutored eye, it looks like the worm damage might get carved out during the process. Unless it’s much deeper than it appears…

[Will Turner]

Going to set it aside for now.   Pivoting to a one piece back with another very old piece of maple also sourced from the same estate.   I did see pencil marks highlighting a hole in the other piece of wood which likely indicated the wood worm.

the one piece is completely clean on the exterior, so should be good 

[Will Turner]

1 minute ago, Colleen McTigue said:

To my untutored eye, it looks like the worm damage might get carved out during the process. Unless it’s much deeper than it appears…

I will give it a try.  Already a shallower arch than I would prefer if I follow my templates.   
 

I will keep it for a model that has a flatter back.  

[Davide Sora]

39 minutes ago, Will Turner said:

I will give it a try.  Already a shallower arch than I would prefer if I follow my templates.   
 

I will keep it for a model that has a flatter back.  

I think it's definitely worth a try. With woodworms, you never know what's going to happen; it might disappear after a few gouge strokes. Or it might be full of holes inside. The only way to know in advance would be to take an X-ray, but that's not within everyone's reach. Even if there are any holes left, it may be worth making small patches to each one, as long as they are not in the soundpost area.

[The Violin Beautiful]

14 hours ago, Will Turner said:

I started a new project that is using some 70+ year old maple from Germany.

while working on it, I have run into worm damage near the join.

Not sure the best technique to fix it.  It sang when I was testing it, so I am reluctant to toss it.

Suggestions?

Wood is not tanned, just very old.

 

 

I’d probably lean toward trying to make it work for a future instrument as well. You could use wood from the offcuts or from rough arching to make some patches that would match well with a very fine gouge. If the damage ends up being much more extensive internally, then you may need to start over, but at least you won’t be left wondering if the piece would have worked. 

[jacobsaunders]

use a different lump of wood

[HoGo]

I wouldn't want to have that piece of wood in my workshop in case there may be a living bug inside. I'd immeditely paint it with bug killer and put it away from my stash.

[Will Turner]

Could "bake" the wood just to be sure.   What temp and duration would one recommend (not to cremate it into ash, but just ensure no living critters).   Was reading that a microwave may be a good approach as any living critters will die quickly.

[Will Turner]

Starting with another maple back.   I used a syringe to fill the voids with hot hide glue and waited for it to cure.   Removing more wood simply reveals even more worm channels.

I don’t like the results and going deeper at this point is not an option.

Oh well, like a wormy apple, you never know what the surprise will be.   It’s really too bad as I haven’t had a piece that felt like it was going to be spectacular like this one could have been.

[Will Turner]

19 hours ago, jacobsaunders said:

use a different lump of wood

Yep, I am using a one piece back now.   Might as well reward myself after that disappointment.

[Brad Dorsey]

8 hours ago, Will Turner said:

…I used a syringe to fill the voids with hot hide glue…

Plain hide glue does not make a good filler, but sometimes substances like wood dust and lycopodium saturated with hide glue are used as fillers.

[Will Turner]

Yeah, I picked up some lycopodium spores for the future.   The existing had maple dust, which is why it's so dark.

[Cathode Ray]

Same story. Started a back from walnut and found issues late in the game. Nostalgic piece of wood so I forged ahead*. Thought I could match better than this...
MinWax does make fillers that work well on spruce. Darker woods are harder to match.

*Acquaintance cut walnut 50 years ago - I've built several guitars with it and this was the last piece. Spruce came from Piagah Forest after a VSA gathering a couple years ago. Thanks again Dave!

Edited May 31 by Cathode Ray
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[alex2036]

Is my violin also damaged by worms? I recently noticed there is a horizontal crack which I dont think I ever noticed few years ago (not sure if this crack is new or was there before). (If the crack is vertical, I will say may be I dropped it or weather cause it.,but it s horizontal)

The outside is still good, no sign of any damage. If there is a live worm in it, how do I kill it? Spray bug killer?

 

[Will Turner]

10 hours ago, alex2036 said:

Is my violin also damaged by worms? I recently noticed there is a horizontal crack which I dont think I ever noticed few years ago (not sure if this crack is new or was there before). (If the crack is vertical, I will say may be I dropped it or weather cause it.,but it s horizontal)

The outside is still good, no sign of any damage. If there is a live worm in it, how do I kill it? Spray bug killer?

 

From the appearance, this was the condition before it was put together.   I would recommend leaving it alone.   No bug spray.

With the violin near the nose I would not recommend poison fumes to be inhaled during practice.

 

[alex2036]

Thank you  Will,   big relief. Ps: honestly,  spray bug killer did cross my mind.