Scroll broke off!

[Don Noon]

This is a scroll I accidentally dropped on the concrete floor when I was almost done.  Just held it together by fingers after gluing, and it's still fine after 5 years. You should make sure the parts are warm, to keep the glue from gelling too quickly.  You will have to hold it together longer, but I think the tradeoff is worth it.

[David Burgess]

21 minutes ago, Don Noon said:

This is a scroll I accidentally dropped on the concrete floor when I was almost done.  Just held it together by fingers after gluing, and it's still fine after 5 years. You should make sure the parts are warm, to keep the glue from gelling too quickly.  You will have to hold it together longer, but I think the tradeoff is worth it.

Tons of surface area on that one, lots of jagged edges to help index correctly, and also very difficult to clamp. One of the restorers at Oberlin might have spent days figuring out how to clamp that adequately.

[Marijan Radaljac]

1 hour ago, David Burgess said:

On a rubbed center joint, the sliding of the two surfaces will work out most of the excess glue. Such a sliding action is impossible when gluing this scroll, without really screwing up the hills and valleys which index together on either side of the break.

Over time, the bonding properties of hot glue can deteriorate badly, if the glue bridges much of a gap or is used as a gap-filler. This is quite different from adhesives like epoxies. I would recommend clamping when possible, which should be pretty easy in this particular case, compared to breaks which involve some combination of weird and complex angles running all over the place.

I agree that it is not quite the same, error chance is low at center joint providing good flat areas. But advantage of "hold joint" is that it is much easyer to realy feel good contact between the areas when ajusting it by hands-fingers that when using jig. And it will be very quick. If glue is on a hot side, not to thick and wood warmed up,  you will squize almost all glue out at the time point when areas align perfectly at resonable hand preassure. 

That is just my limited expirience though so I am really not in position to argue about this subject with you. As I said, well made and applied jig, most probably better and safer option. I had just two similar cracks as OP and one across A peg hole. The last one I solved using jig .

[Ken_N]

I cut the mortise in, close to size, and to depth past the pre drilled holes before I do anything else. I don't use a mallet.  Everything is still solid, and can be used as leverage.  I learned that from Melvin.  Tried it, and it works.  

I would just glue it.  Hold it with your fingers for a while, and tomorrow it will be fine.

Really.

Ken

[Emilg]

At the risk of being banned from the Pegbox .. could Titebond original be a better choice than hide glue?

There is no risk of creep or acoustical problems, and there won't be any need to undo this joint.

[Urban Luthier]

if it were me, I'd fix it using Jacob's clamping method 

[MeyerFittings]

I've made many modern guitars in my career. None of them were one piece necks. All had a head joint and heel block, all were glued with Titebond (that was how I learned). All are still viable after forty (yes unfortunately) years. My old maestro now uses one piece necks but he has tons of wood that he bought when it was more available and less endangered. I may have used hide glue on my Baroque guitars but I can't remember. They had V joints, so more surface area and less tension. I repaired a few broken Rickenbacher basses. One was so shattered thatI I had to  make a new head and glue it on to a flat diagonal joint. I used epoxy for that one (thin necks tremendous tension). Ironically one steel string was dropped by the owner on the head and it broke at the heel and not at the joint. I kept notes on much of this so I would remember things, but I can't remember where they are. C'est la Vie.    

[David Burgess]

2 hours ago, Urban Luthier said:

if it were me, I'd fix it using Jacob's clamping method 

I probably would not. It's an easy enough break to clamp (unlike Don's), and I have never seen any of the many world-class restorers we have brought in to the Oberlin Restoration Workshop recommending a sustained human-body-push  for gluing any scroll or pegbox separations.  If Jeffrey or Jerry Lynn  or Claire Curtis or Pablo Alfaro or Marylin Wallin or any of the many other people who have been involved in these workshops for many years have witnessed anything otherwise, I am perfectly willing to be corrected.

[jezzupe]

My opinion it that with something like this that is intended to be a permanent fix, that "we" won;t ever be trying to take apart , the hands down best and easiest solution would be Smiths epoxy. This epoxy will glue it very permanently and very strong but not need any clamping to achieve a strong bond. It has a very long open time and allows for adjustments up to 20 minutes after putting the pieces together , if it is a clean crack that lines up well as shown, you'll just need to balance the fiddle so the broken part can balance without tipping and just push it into place, walk away, check it 10 min, if its staying in place, leave it and the next day it will be the strongest part of the violin. 

 

https://www.defender.com/product.jsp?id=2915035

[jacobsaunders]

44 minutes ago, David Burgess said:

 I have never seen any of many the world-class restorers we have brought in to the Oberlin Restoration Workshop recommending a sustained human-body-push  for gluing...

You never invited me

[Urban Luthier]

58 minutes ago, David Burgess said:

I probably would not. It's an easy enough break to clamp (unlike Don's), and I have never seen any of many the world-class restorers we have brought in to the Oberlin Restoration Workshop recommending a sustained human-body-push  for any scroll or pegbox separations.  If Jeffrey or Jerry Lynn recall otherwise, I am perfectly willing to be corrected.

From a pro point of view I expect you are right... What I meant was, that an amateur (like myself) would have greater success, doing what Jacob suggested -- carefully hand clamping the clean break with hide glue. Creating and successfully using a fixture like the one illustrated in Weisshaar p192) may be more difficult than it looks. With out the right experience I expect it would be easy for the joint to slip under clamping pressure.

By the way I've created a Ukulele neck using the diagonal joint method Eric notes above. I expect the joint is actually stronger than the rest of the neck!

 

[arglebargle]

6 hours ago, JohnCockburn said:

good argument for hollowing out at least the bulk of the pegbox before carving the scroll...

Yes, this. It allows one to work the pegbox without worry.

Something like this: 

[David Burgess]

4 hours ago, Urban Luthier said:

From a pro point of view I expect you are right... What I meant was, that an amateur (like myself) would have greater success, doing what Jacob suggested -- carefully hand clamping the clean break with hide glue.

Maybe so. Multiple pages could be written on how valuable that approach can be, along with the many exceptions,

[bkwood]

5 hours ago, Ken_N said:

I would just glue it.  Hold it with your fingers for a while, and tomorrow it will be fine.

Really.

Ken

I agree. It may or may not be easy to clamp, but if it fits cleanly there is no need. Excessive pressure isn't called for with hide glue, good fit is. A couple minutes holding with your fingers is enough to set the pieces together, then set it aside overnight.

[Nick Allen]

1 hour ago, Urban Luthier said:

 

By the way I've created a Ukulele neck using the diagonal joint method Eric notes above. I expect the joint is actually stronger than the rest of the neck!

 

That would be a scarf joint. Most guitars with an angled headstock exhibit them. 

[Papageno]

Thank you all for the advice!
I haven't gotten around to fixing it yet, but I think I'm just going to go the hand clamp route.

I have a spare neck block, so I'm prepared to start over, but I'd like to see how it glues up first.

Thanks once again! I'll post pictures when it's back together.

[Evan Smith]

How about an exploding bolt,,,

they're fairly discreet

[Brad Dorsey]

On ‎1‎/‎11‎/‎2019 at 6:29 AM, jacobsaunders said:

...With an antique instrument, I would definitely be in the “glue it back on with your fingers, and leave it overnight” school...

Jacob,  How long holding it together by hand do you think is adequate?

[Stavanger]

17 minutes ago, Brad Dorsey said:

Jacob,  How long holding it together by hand do you think is adequate?

Until your fingers go numb. (Answering although the question was not targeted towards me)

[Marijan Radaljac]

42 minutes ago, Stavanger said:

Until your fingers go numb. (Answering although the question was not targeted towards me)

Actually, no need for that. For the OP crack (at least as I have done in my two cases) just try to rest your left palm on the legs, hold the neck/pegbox with heal facing away from you, and use 3 inner fingers of the right hand to keep the scroll in contact position. 2 and half to 3 min is all I did. No need to say, both scrolls are holding after quite a few years. You should need 10 sec max (even less) to aligne parts in register and apply the preasure to the contact area after you apply the glue on, and squize the ecxcess out. 

[jacobsaunders]

2 hours ago, Brad Dorsey said:

Jacob,  How long holding it together by hand do you think is adequate?

I always count till 20 slowly, ie. one elephant, two elephants…., then put it down somewhere where it will not be in the way of children, women with vacuum cleaners or any such, and don't go near or even touch it untill the next day.

[Marijan Radaljac]

Hmm, so 3 min is overkill? Although, I was counting one blue whale, two blue whales... in latin. 

[Rue]

2 hours ago, jacobsaunders said:

... where it will not be in the way of...women with vacuum cleaners or any such ...

No concerns about women with swords or rifles? 

[MeyerFittings]

If you think it's bad over here Rue, you should go over to the divorce post.

 

[Muswell]

What's a vacuum cleaner?