Brace repair through the f-hole

[rcc56]

Thank goodness for the violin supply houses. I have a '40's A-50 on the bench with loose tone bars.

After careful study, I determined that with the right palette knife, I could turn the instrument over and spread glue under the tone bars without making too much of a mess. Two "f-hole patching clamps," one with a 2" throat, the other with a 4" throat, purchased from International Violin Company, made it possible to clamp the tone bar through the f-hole. After some thought, I settled on Titebond I-- I didn't think I could get everything buttoned down fast enough for hide glue.

The f-hole patching clamps made it possible to do this job without taking the back off the instrument. Neither Stew-mac nor LMI sells a clamp that will work in this situation. They are only available from the violin supply houses.

I now have 5 palette knives with blades of various shapes and lengths. The last two I bought came from the local artist's supplier. I used both of those on this job. I guess the reason for this thread is to encourage repair people to seek sources other than just Stew-mac and LMI for tools. You might find something you need that they don't carry. The jeweler's suppliers have all kinds of files, pliers, and burs of many shapes and sizes that will work in a Dremel.

I just finished gluing the bass side tone bar. The treble side will have to wait until tomorrow because I had apply one of the clamps through the opposite f-hole to get it to stay put.

It's better not to drink too much coffee before a job like this.

[Jonathan Ward]

Thanks for the tip. I never knew International Violin carried six pages of clamps.

[rcc56]

Another similar supplier is Metropolitan Music.
I have used both of these suppliers for shellac, varnish, hide glue, etc. If you get hide glue from them, order the "grade 222", not the "grade 315."

I did have to pad the lower jaw of these clamps for part of this job.

[pops1]

I have a set of those same clamps, they are a lifesaver for certain things. I also use feeler gauges screwed to the end of broken violin bows in different lengths and different thickness for reaching in to spread glue into places hard to get at. I slot the bow and set the feeler gauge in and drill a hole in the bow where the hole is in the feeler gauge and put a small wood screw to pull it tight. Some are two inch handles, some are ten inch handles. Dowels would work, I just happened to have some broken old bows and liked the wood better.

[rcc56]

Well, I tend to resist buying tools unless I really need them, but I couldn't have pulled off this job without these clamps. The job went off without a hitch, and everything is now good and tight.

Hopefully, the mandolin will sound much better, but I'll have to delay that report until I get a set of frets in her. I may also use the same clamps to press in the last few frets-- seems to be a good way to deal with the frets that fit in the unsupported fingerboard extension.

[rcc56]

Verdict: The clamps worked well for gluing the braces. They are not any good for pressing frets-- there is too much spring in them.

The mandolin is no cannon, but it certainly sounds stronger and fuller than it did before I repaired the braces.

I ended up using a file to reduce the dimples a few thousandths on the tang on frets 16 through 20, filed the square end off of the back of the tang, and gently tapped them in with no problems.

These clamps should be long enough and small enough for tone bar repair on an F-5. The bottom jaw should be padded or cushioned to avoid making a depression in the back of the brace.