Jump to content
Maestronet Forums

Pegbox Repair Question


Thomas Knight
 Share

Recommended Posts

14 hours ago, Brad Dorsey said:

I think there must be some good reason why the peg box should be cut first, but I am unable to articulate it.

If you cut the pegbox to fit the neck insert, you run the risk of :o cutting out too much wood.  Much safer to cut the pegbox receiving end with no compromise, then fit the neck into that.  If you frig up a neck block it sucks, but not as much as ruining a scroll from a valuable instrument.  

Link to comment
Share on other sites

  • Replies 70
  • Created
  • Last Reply

Top Posters In This Topic

4 hours ago, jacobsaunders said:

Was there a particular reason to sand the varnish off the pegbox almost to the e peg hole, also from the top of the peg box? You would have got shouted at here for that.

 Jacob, as usual you are right. I have thick skin so I welcome your scolding. I am not making excuses, but the water seemed to wash off the varnish where the cracks were and I am not sure why. I didn't use hot water, just room temp.  It seems like the scroll was possibly revarnished in the past as it does not display the same numerous 'layers' the body has and is chipped and scratched everywhere. There is a serial number or ID scratched into the bottom of the pegbox so I figured the entire scroll may need to be revarnished. I am probably wrong. 

  I used a rat tail rasp to rough cut the ducktail and went around the sides and then used emery cloth strips to eliminate the rasp marks. I went to 180 grit so far. I still have 220 and 320 to go. I scraped the top of the insert until I started to see the varnish on the top of the pegbox scrape off. It literally scrapes off with a fingernail.

2 hours ago, rudall said:

I was wondering that. 
The cracks that were the original topic of this thread aren’t exactly what I would call closed....
The graft itself looks a bit gappy as well. Why did it need to be done?

 The neck too short, the entire scroll/pegbox angled and twisted. When I clamped the cracks I was concerned about being able to close them. The gap closed considerably, but I did not want to distort or crack the wall and make it worse. The expert here said the bushings in there were done with the cracks simply filled with glue, probably many decades ago and the wood distorted so much that he thought they closed as much as possible unless I extended the G crack by cutting into the wood so it could close. He didn't think that was a good idea. The front part by the E closed almost completely. The treble side D did close, but it also was an old repair where a bushing was inserted. The expert is out of town for a few days and he may insert a sliver in the openings. He said to wait before I do bushings so he can decide. I am not looking for accolades, I am asking for true opinions so eventually someday I will hear from the best out there 'well done'.

 

2 hours ago, Wood Butcher said:

Indeed, neither seem to be well done.

This is what happens with amateur repairs, blundering through, with little quality at the end. That such work is applauded by others, who are even worse, is a sad state of affairs. :(

 How else can an amateur become an expert? Yes, we blunder, and we learn. I post these pics so I hear the truth, even if I don't like it. I honestly do take your remarks as a learning opportunity. Many years ago I was an automotive apprentice and eventually a certified R R master tech at a Rolls Royce dealership. I got a finger wagging every time they let me off the leash, but I embraced those lessons. My next graft will be cleaner, tighter, less varnish lost, etc.

 

1218655963_20210725_1518091.jpg

Link to comment
Share on other sites

4 hours ago, Wood Butcher said:

Indeed, neither seem to be well done.

This is what happens with amateur repairs, blundering through, with little quality at the end. That such work is applauded by others, who are even worse, is a sad state of affairs. :(

Right I’m sure during your apprenticeship there were no blunders and quality issues… 

The OP has indicated time and again his need for advice of his methods instead of berating and ridiculing his methods. I applaud him for his tenacity to display for us his restoration and gaining what little knowledge he’s gained here. I for one wouldn’t even have posted these repairs on what may have not been an instrument of high value but then again a small minor repair on my guitar for a small crack has gained me all sorts of ridicule! 

Link to comment
Share on other sites

44 minutes ago, PaganiniGuitar said:

Right I’m sure during your apprenticeship there were no blunders and quality issues… 

The OP has indicated time and again his need for advice of his methods instead of berating and ridiculing his methods. I applaud him for his tenacity to display for us his restoration and gaining what little knowledge he’s gained here. I for one wouldn’t even have posted these repairs on what may have not been an instrument of high value but then again a small minor repair on my guitar for a small crack has gained me all sorts of ridicule! 

It is fine by me as long as the comments are constructive and most have been.

I overtorqued a hyraulic accumulator bolt on a 75 RR Corniche and stripped the threads in the block. My old torque wrench was frozen inside. It became my lesson on helicoiling stripped out holes, with the British shop foreman saying 'We simply don't do things that way, my boy". "Check and recheck your torque numbers and plan to work this Saturday and Sunday as well as next weekend". British tough love, I say.

Link to comment
Share on other sites

36 minutes ago, Thomas Knight said:

It is fine by me as long as the comments are constructive and most have been.

I overtorqued a hyraulic accumulator bolt on a 75 RR Corniche and stripped the threads in the block. My old torque wrench was frozen inside. It became my lesson on helicoiling stripped out holes, with the British shop foreman saying 'We simply don't do things that way, my boy". "Check and recheck your torque numbers and plan to work this Saturday and Sunday as well as next weekend". British tough love, I say.

Agree on the constructive learning bits and pieces whenever it comes.

As a retired aerospace engineer I know about the things you do and don’t do or at least ask questions. As a professional engineer we can’t make mistakes when peoples lives are at stake lucky for us we pay for malpractice insurance. Playing with violin repairs and the like I think we can surely say no one will be affected but for the pride and or small monetary loss in value of an instrument. Currently I am restoring a Modesto Borreguero guitar of the 1920’s vintage that gives me pride in seeing this work done. Antonio de Torres is the Stradivarus of guitar, Modesto Borreguero would be the Maggini of violin prominence comparison.

Link to comment
Share on other sites

1 hour ago, Thomas Knight said:

Getting back to the main focus, this old and tired scroll I have has had both a short and a long graft done to it as well as lots of other work. Can anyone elaborate on why a short or long graft were used, and was it regional?

2044017347_20210725_1726181.jpg

328178718_20210725_1726351.jpg

Interesting that this repair done previuosly by I assume some luthier or repair person closely matches the repair you just made. I find your pegbox repair much better than this example.

Link to comment
Share on other sites

15 minutes ago, PaganiniGuitar said:

Agree on the constructive learning bits and pieces whenever it comes.

As a retired aerospace engineer I know about the things you do and don’t do or at least ask questions. As a professional engineer we can’t make mistakes when peoples lives are at stake lucky for us we pay for malpractice insurance. Playing with violin repairs and the like I think we can surely say no one will be affected but for the pride and or small monetary loss in value of an instrument. Currently I am restoring a Modesto Borreguero guitar of the 1920’s vintage that gives me pride in seeing this work done. Antonio de Torres is the Stradivarus of guitar, Modesto Borreguero would be the Maggini of violin prominence comparison.

  When I switched in '78 to the performance market I received an FAA certification for Aircraft Turbochargers. 'You cant park a plane on a cloud' was the phrase. Redundancy was the norm.

  I have some expensive violins in need of repair somewhere down the road. The last major repair was a sound post patch to the back of a JB Squire done by a Cremona trained luthier. $1400 in 2010. Top luthiers are worth their rates because of the incredible work they do.  I admire the years of training and practice.

Your guitars sound amazing. I have some 80's 'big hair' USA electrics in my collection.

I have never seen a scroll with 2 grafts. They are probably 100-200+ years old. I am certain they looked much better than mine when first done.

Link to comment
Share on other sites

Yes the redundancy for aircraft systems but little do passengers know or are aware when the one system fails and another takes over to continue safe flight. Reminds me of when Paganini broke his strings but continued his performance on one or two strings… the performance must go on!

Sounds like you have your hands full with instruments in need of TLC… I’m sure that graft was nice in its day and if they accomplised that I’m sure your graft will stand the test of time as well.

Link to comment
Share on other sites

On 7/24/2021 at 10:00 PM, Brad Dorsey said:

It looks like the graft fits very well to me.

But I am uncertain how you prepared the joint.  As I understand it, you used a router bit mounted in a router and guided by the aluminum jig that you made on the Bridgeport.  Questions:

Did you use the router to make cuts in both the new neck block and the peg box?

Did you use the router to cut the bottom surfaces of the graft or just the sides?

If just the sides, how did you cut the bottom surfaces?

Was the graft joint entirely machine-cut or was there some hand cutting and fitting?

Did you do anything to remove the machining marks from the machine-cut surfaces?

Did the cracks close after you removed the bushings?

I would like to see a picture of a neck blank mounted on the jig.  Also a mounted peg box, if you machined the peg box.

  Hi Brad,

  I mounted a piece of pine on the fixture so I could do a quick description for the neck blank. Pine is softer than maple so the cuts wont be quite as nice.

Pic 1--a side view of the clamps and fixture with a piece of 2 x 4 I had laying around cut to 2.5" x 1.25" x 12"

Pic 2--top view with the blank bolted in place

Pic 3--fixture with blank mounted in a vice

Pic 4--sides cut 1" deep with the taper

pic 5--.250 bit, .500" bit to be used on the router table to do the bottom of the tapered area 

Pic 6--old router table with radius bit

Pic 7--roughed insert side view

Pic 8--roughed insert top view

Pic 9--closeup of cut

This took 30 minutes total.

 

I rushed this more than I usually do because it didn't matter but I think you see how it's done.

20210726_201040.jpg.a09dd57ce4846a405bf8565a50d871f7.jpg

20210726_112123.jpg

20210726_112138.jpg

20210726_112217.jpg

20210726_112918.jpg

20210726_113807.jpg

20210726_144005.jpg

20210726_144021.jpg

20210726_144053.jpg

Link to comment
Share on other sites

14 minutes ago, violguy said:

I am curious about what a Deckel machine looks like. Would anyone be kind enough to post a picture of one?

Thanks in advance

Rather ungainly!  I’m 4 feet from mine at the moment with a phone, but it’s disassembled….  I’ll find a decent image and post it.

Link to comment
Share on other sites

18 minutes ago, David Burgess said:

Gad zooks! Is that a duplicating machine?

Hi David, yes, they were both an engraving and a profile copy machine with ratios is 1:1.5 down to 1:10. I wanted to make a few custom bridges so I drew a bridge at a 1:4 ratio on carboard (4 times larger than the bridge I want to carve) and the reduction allows for extremely accurate freehand work. The ideal way is to 3D print the model you want in an oversize buck (the term used for the part to be duplicated) and because the GK models are 3D they can do complex copies down to radius, etc.

Link to comment
Share on other sites

37 minutes ago, jacobsaunders said:

If anyone tried to take a violin of mine anywhere near one of those, I think I would run a mile

I agree with you 100% Jacob. A few years ago I would have thought why not, but after hearing all the facts why machines should not be used I have concluded that the top luthiers out there are even more accurate than the machines and there is very, very little chance of catastrophic failure if done by hand. I had a cheap new scroll I wanted to cut on my fixture and when doing one pegbox wall it went fine, but the other side broke off a huge piece even with me being slow and careful, and it was a new in the white scroll. So once again, as usual, the student is wrong and the professor right. Who would have thought?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.




×
×
  • Create New...