Repairing gouges in top plate on exterior of instrument

[sabaugher]

Hey guys!

 

I have an old trade instrument that I'm cutting my repair teeth on (don't worry, it was long gone as a functional instrument when it got to me). One of the things I'd like to do is to repair a couple of deep gouges on the exterior o the top plate. In some places, the gouge is about 1 mm deep and covers a surface area about the same size as a quarter. I was thinking that I could sand the area down and patch it, like one would do to make a soundpost patch on the interior of the top plate. But, before I did that, I wanted to ask if there is any existing, accepted method for an exterior gouge repair? Or does anyone have some war stories they'd be willing to share? 

 

Thanks in advance, guys!  

 

-Sarah

[Jeff White]

Sarah, this is tougher than it might seem to be done well.  Being only a 1mm deep (A bow holder "grindout" I suspect), I think your only choice is to clean it well, seal it with shellac, then fill it with something like a shellace,sandarac,copal mixture. (or you could just use deft).  Harder than it looks because it us difficult to get it to match the top arching curve.  Difficult also because you are then having to reproduce the grain lines over that area and touch up.  Not an easy touch up, to say the least.  You might just consider just color matching the area with touch up varnish and having that just not be so obvious(this is not a fix, just less of a distraction).   jeff

[David Burgess]

What's your experience level? Do you already know how to make plaster molds?

[Johnmasters]

Hey guys!

 

I have an old trade instrument that I'm cutting my repair teeth on (don't worry, it was long gone as a functional instrument when it got to me). One of the things I'd like to do is to repair a couple of deep gouges on the exterior o the top plate. In some places, the gouge is about 1 mm deep and covers a surface area about the same size as a quarter. I was thinking that I could sand the area down and patch it, like one would do to make a soundpost patch on the interior of the top plate. But, before I did that, I wanted to ask if there is any existing, accepted method for an exterior gouge repair? Or does anyone have some war stories they'd be willing to share? 

 

Thanks in advance, guys!  

 

-Sarah

I think many people would agree that repairs and retouching as you have asked about are more difficult than making a new violin.  I know that I made a passable violin at 16,  played it for some time.  The cosmetic aspect of repairs,  on the other hand,  is very difficult.   Notice how many posts discuss a better varnish or ground.  These are all about appearance first,  and one hopes for tone also of course. 

 

You are starting at the wrong end of the skills range.

[Brad Dorsey]

...I wanted to ask if there is any existing, accepted method for an exterior gouge repair?...

 

I don't know how accepted it is, but there is very challenging procedure that I think David is alluding to.  It involves removing and casting the top, correcting the cast, thinning the inside of the top in the area of the gouge to an even thickness, pressing the thinned area of the top into the cast, fitting a patch on the inside of the top, regluing the top to the ribs and touching up the varnish.

 

The problem with patching from the outside is the impossibility of matching the patch wood to the top wood.  The method outlined above leaves only original wood visible from the outside and the patch on the inside. 

[sabaugher]

Hey guys,

 

Thanks for your advice, especially Brad Dorsey. I'd love to hear more from David Burgess! To answer your question, my skills are untried at wood working beyond bridge making, but I am a quick and attentive learner. And that is what this violin is for... to learn on. So, sock it to me! What method would you propose?

 

I should probably also mention that I've already taken the top off this instrument and stripped the varnish off the whole thing. I'm also experimenting with some edge doubling where the the edging is really beaten up. When I said I was cutting my teeth on this instrument, I was serious  

 

And, John Masters, what skills would you recommend I work on first? I am already practiced in fitting, shaping, and tone matching a bridge to the top plate, installing the sound post, and taking care of the other aspects of violin/ viola set up. I thought that this clunker instrument would be a good opportunity for me to delve into some more serious issues of wood working and repair, focusing more on creating structural stability in the instrument. I plan to re-varnish the violin myself in the coming weeks, and I of course want to achieve a pleasing cosmetic finish, but this is a secondary goal and one that I won't be terribly worried about missing on my first go-round with serious body repairs. Taking into consideration my mindset as stated, I'd still love to hear any advice you have for me. 

[UG Fiddlesmith]

Go for it Sarah; when you have completed whatever you tried to do you will have learned something and made a step into the fascinating field of instrument restoration.  The trade fiddle is a good one to start on, nothing to lose and everything to gain.  Just because the repair might not look perfect or invisible doesn't mean it won't play well or sound good.  Use plenty of patience and keep on asking questions and keep on reading.  Another North Carolina fiddler, fixer and maker.

[sabaugher]

Thanks, UG Fiddlesmith

[Violadamore]

Sarah, the first skill I would advise perfecting is sharpening all of your carving tools to as microscopically perfect an edge as possible.  Everything else depends on this, IMHO. Techniques (and there are several used by different posters) for this may be found on MN.

[Jeff White]

Sarah, the first skill I would advise perfecting is sharpening all of your carving tools to as microscopically perfect an edge as possible.  Everything else depends on this, IMHO. Techniques (and there are several used by different posters) for this may be found on MN.

Agreed, you will accomplish little until you get this right.  Hans Nebel has a great beginner introduction week of violin repair  work in the Berkshires every summer, amoungst other courses too.   jeff

[Johnmasters]

 

And, John Masters, what skills would you recommend I work on first? I am already practiced in fitting, shaping, and tone matching a bridge to the top plate, installing the sound post, and taking care of the other aspects of violin/ viola set up. I thought that this clunker instrument would be a good opportunity for me to delve into some more serious issues of wood working and repair, focusing more on creating structural stability in the instrument. I plan to re-varnish the violin myself in the coming weeks, and I of course want to achieve a pleasing cosmetic finish, but this is a secondary goal and one that I won't be terribly worried about missing on my first go-round with serious body repairs. Taking into consideration my mindset as stated, I'd still love to hear any advice you have for me. 

If you are going to revarnish,  would you strip first?  In that case,  I would strip a place without scratches and see what color the wood is.   It is likely to be pretty white.. most violins have some kind of a sealer,  and Zip-Strip leaves them very light.  You don't want to risk over-darkening the marks.

 

Then perhaps color the destroyed patches with a light glue seal and some dilute water color.  Water color and French polish seem to have been popular at one time.  Color varnish does not seem to work well,  the color is too dilute.  Others will disagree,  I am sure.

 

 

Old German violins seem to have a glue size or similar,  and this is not touched by the chemical sealer.  After stripping,  I have always gone over with 0000 steel wool and lacquer thinner.  Then it is like a clean white violin,  with a little tanning.  I have never used a lye-based stripper.  Or a water-soluable one.

 

 

Skills?  I was just saying that retouch was difficult.  It does not derive from other skills,  but it is just difficult.  Being a good art painter might help.