View previous topic :: View next topic |
Author |
Message |
Mat Roop Senior Member
Joined: 24 Mar 2007 Posts: 911 Location: Wyoming Ontario
|
Posted: Tue Mar 27, 2007 11:04 pm Post subject: split A peg hole |
|
|
Hope this post works with the pic... I have a violin with a split peg hole... Checked my (expensive) W&S manual and find no reference to this common problem.... drats!
So I am looking for some advice as to what the current professional opinion is as to the best way to tackle the problem...and solve it!
Thanks for your great advice!....Mat
[img][/img] |
|
Back to top |
|
|
Mat Roop Senior Member
Joined: 24 Mar 2007 Posts: 911 Location: Wyoming Ontario
|
Posted: Tue Mar 27, 2007 11:11 pm Post subject: Re: split A peg hole |
|
|
I was so excited about being able to post a picture, that I forgot to mention to add that there has been a previous attempted repair as there is some stuff in the crack....and evidence of a tiny dowel set in from the top edge of the pegbox wall. Thanks, Mat |
|
Back to top |
|
|
mapleleaf_gal Member
Joined: 24 Mar 2007 Posts: 73 Location: tucson, az
|
Posted: Wed Mar 28, 2007 1:06 am Post subject: |
|
|
i have repaired this exact same problem a few years ago. i graphed a piece of wood on the inside of the peg box. kind of like when you graph a scroll onto a new peg box.
sorry, that may not be very clear. and i dont have a picture to post. |
|
Back to top |
|
|
Leif Luscombe Site Admin
Joined: 19 Mar 2007 Posts: 126 Location: Mount Elgin, Ontario, Canada
|
Posted: Wed Mar 28, 2007 7:43 am Post subject: |
|
|
You will need to cut away about 1/3 to 1/2 of the thickness of the pegbox wall on the inside of the peg box, in the area of the crack (the highlighted area). It won't be seen from the face. Make sure that the grain of the graft is not paralell to the crack.
_________________ Leif Luscombe
Violin Maker and Dealer
The Violin Forum Moderator
Last edited by Leif Luscombe on Wed Apr 04, 2007 9:54 am; edited 1 time in total |
|
Back to top |
|
|
Michael Darnton Moderator
Joined: 23 Mar 2007 Posts: 1281 Location: Chicago
|
Posted: Wed Mar 28, 2007 8:10 am Post subject: |
|
|
It's a bit hard for me to tell what's going on from the photo. If the crack can be glued (and I can't ascertain that), a common way of fixing this is to ream the hole and put in a spiral bushing. The spiral takes the pressure of the peg, preventing the crack from being stressed again. Often this will do the job--it depends on how nice the crack is, and how far the hole is away from the edge of the wood. in order to move the peg back away from the edge, and give a nice peg bearing surface, if the hole is large it's common to put in a spiral for reinforcement, followed by a regular bushing inside, which is then drilled off-center to place the peg where you want it.
If everything is nasty, then removing wood is the way to do it. I was taught to do this on the outside, removing almost all of the crack, with a hole with sloping sides similar to a post patch, insetting a matching piece of wood with the grain running the same way, and covering the patch with a veneer chosen to match perfectly that feathers out gradually to nothing. If this is well done, no one will ever see it. This is a whole lot of work, and you have to be able to do each step perfectly, or you just end up with a mess.
The way Leif describes is difficult to make a perfect fit, since you're working in a tight place, and If I did that, I wouldn't make the patch perpendicular--perhaps a few degrees off would be enough. It's a hard repair to make invisible, and if the wood is going in a contrary direction, seasonal changes will reveal it quickly. Structurally it's fine, and makes less of a mess of the outside if you don't do it well.
Another situation where an inside patch won't work is if the crack is running up above the open part of the pegbox, which is sometimes the case. |
|
Back to top |
|
|
Mat Roop Senior Member
Joined: 24 Mar 2007 Posts: 911 Location: Wyoming Ontario
|
Posted: Wed Mar 28, 2007 7:20 pm Post subject: |
|
|
Thanks everyone... I like the idea of the spiral bushing... approx how thick would the spiral band be when done? and I presume it would be maple, and wound into 2 or 3 revolutions??
Thanks, Mat |
|
Back to top |
|
|
Michael Darnton Moderator
Joined: 23 Mar 2007 Posts: 1281 Location: Chicago
|
Posted: Wed Mar 28, 2007 9:10 pm Post subject: |
|
|
I can usually handle about four inches of wood for a spiral, and I'd do two, if the size allowed it. I don't really know how many turns that is, though. |
|
Back to top |
|
|
Leif Luscombe Site Admin
Joined: 19 Mar 2007 Posts: 126 Location: Mount Elgin, Ontario, Canada
|
Posted: Wed Apr 04, 2007 10:03 am Post subject: |
|
|
Judging from the picture, the crack seems to be old and dirty. In this case, simply attempting to glue it to fix the problem would probably not be very successful.
Michael's suggestion of a spiral bushing is a good one, the only trouble may be that with an A peg you don't wish to enlarge the hole (which would further weaken the peg box), so after fitting the spiral, the peg may need to be smaller than the other pegs (which can have its own set of drawbacks).
I changed my original post on this thread. Michael is correct that the grain should not be perpendicular to the crack, however, it should be at an angle to reduce th possibility of further action in the area. In the end I may consider a 1mm graft on the inside, and a spiral bushing. The 1mm piece shouldn't be too difficult to fit, and combined with the spiral bushing (and the best possible clean-up and clue job of the crack itself), should yield a fairly robust repair. _________________ Leif Luscombe
Violin Maker and Dealer
The Violin Forum Moderator |
|
Back to top |
|
|
Mat Roop Senior Member
Joined: 24 Mar 2007 Posts: 911 Location: Wyoming Ontario
|
Posted: Thu Apr 05, 2007 12:03 am Post subject: |
|
|
Thanks for all your help... but one more question...before I tackle the issue...what method do you suggest to pressure the spiral bushing (which I suspect is very delicate once soaked with glue) against the walls of the peg hole.
Here is what I am proposing...
1-clean split with warm water, and a stiff brush and reglue split with thick hide glue.
2- ream out pegholes to clean wood and then some.
3- dip spiral shaving (enough for 2 to 3 wraps... my shaving is about 0.2 mm thick) in glue & curl it around a small shaft and place into peg hole where it should expand somewhat to release the shaft
4- push in a poly covered peg of same taper as hole till spiral is tight, and let set
My concern is that when I push the peg in it will push the spiral out the other side? and the spiral will not have much strength to hold it in from the other side. Is there a scientific way to do this or is it one of those jobs where you just hope for the best ..... Thoughts?
Thanks, Mat |
|
Back to top |
|
|
Jeffrey Holmes Member
Joined: 03 Apr 2007 Posts: 90 Location: Ann Arbor
|
Posted: Thu Apr 05, 2007 8:41 am Post subject: |
|
|
Mat Roop wrote: | My concern is that when I push the peg in it will push the spiral out the other side? and the spiral will not have much strength to hold it in from the other side. Is there a scientific way to do this or is it one of those jobs where you just hope for the best ..... Thoughts?
Thanks, Mat |
Mat;
I'd make an effort to clean the crack with as little manipulation (that stiff brush you mentioned) as possible. You want as much wood to wood contact as can be had... and manipulation tends to break up the fibers at the surface and round the edges at the outside of the crack. Try pumping the water through the crack and carefully lift off the dirt and old glue from the surface with a paper towel. I know you mentioned that the area was repaired before... so preserving what remains of the areas integrity will be all that much more important.
Also, you may be planning this already, but I'd suggest, once the crack is clean and all traces of old glue are removed, that you clamp it closed and allow it to dry completely, in position, before gluing it.
If you can manage to get that crack closed and stable, make sure you install the spiral bushing (wound) in the direction that will allow smooth reaming later on (install it so the reamer does not catch an edge and tear the bushing).
If you turn the "peg" while pushing it (slowly) in the direction that would uncoil (expand) the bushing, and the bushing is wide enough to allow just a bit of "travel", it should help get it tight without running it out of the pegbox wall. You might want to be a little careful about the pressure applied to the side with the crack... tight enough to get a good glue joint, not tight enough to force the crack to re-open.
Best of luck. Let us know how it goes. _________________ Jeffrey
http://holmesviolins.com |
|
Back to top |
|
|
Mat Roop Senior Member
Joined: 24 Mar 2007 Posts: 911 Location: Wyoming Ontario
|
Posted: Thu Apr 05, 2007 4:29 pm Post subject: |
|
|
I am beginning to see that a fairly wide bushing will be the key.
Thanks for all your advice!
Mat |
|
Back to top |
|
|
Ed Junior Member
Joined: 02 Apr 2007 Posts: 17 Location: Merrimack, NH USA
|
Posted: Mon Apr 23, 2007 10:48 pm Post subject: |
|
|
Michael, as I understand what you said about inserting a patch - you first excavate and fit a maple with-the-grain patch from the outside of the pegbox surrounding the cracked area. Once glued and dry, then excavate the just-installed patch to install a veneer (1mm thick?) over that, fading out to nothing at some point. Is that right? Do you also chalk fit the veneer? Or is there some way to get a flat surface over the patch etc to allow just gluing the veneer? Any pics available of this process? - Thanks!
|
|
Back to top |
|
|
|