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catbrain Member
Joined: 22 Sep 2023 Posts: 49 Location: Greeneville TN.
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Posted: Thu Jun 12, 2025 3:52 am Post subject: maintaining shape when top off ? |
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so I took the top off this pretty cheap violin (15$ at goodwill) and discovered that the bass bar was loose at both ends and barely held on in the center. I expect that what was making the giant buzzing noise
The top side linings were crap so I replaced them with new. However I noticed that the sides seemed to want to spring outward and away from the shape that the mold would have been. And that meant that the body would no longer fit the top plate. So I tore my linings out --- and built a set of "jaws" to squeeze the center bouts in using tapered wedges. That held it in to match the top plate and I re- did the linings. That seemed to have "fixed" the body to the approximate width of the top. Once the glue had set on the linings I removed the compression device and they body maintained it shape- more or less.
i did notice once I glued the top back on- that the fit wasnt as precise as I would have liked- one of the corners was slightly out of position.
So when one takes a top off- is it "normal" for the body to spring open like that ? None of my self built ones had ever done that-----
Is that an artifact of this cheap thing being built in some kind of strain situation from the beginning ? Just wondering.....
Tim |
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John Cadd Super Member
Joined: 23 Jul 2009 Posts: 1344 Location: Hoylake
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Posted: Fri Jun 13, 2025 7:59 am Post subject: Maintaining shape |
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This is a complicated question . How did they manage to assemble it with the tension .I would guess using an external mold as a clamp while the top and back were glued on. Maybe operated by automated machines .So it would be made too wide first and then machines would press it in with bits to position the corners and then clamp on top and back.Maybe suction cups to grip the surfaces . More like a car factory on a small scale .
Did you only remove the top or take the sides right away from top and back ? |
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catbrain Member
Joined: 22 Sep 2023 Posts: 49 Location: Greeneville TN.
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Posted: Fri Jun 13, 2025 4:34 pm Post subject: |
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only the top removed ----
would LOVE to see the factory---- prob an abomination---- |
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John Cadd Super Member
Joined: 23 Jul 2009 Posts: 1344 Location: Hoylake
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Posted: Sun Jun 15, 2025 9:29 am Post subject: Maintaining shape |
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| The linings will make the sides a lot stiffer .You might need to make a mini mold for the worst bits.Take off the lining in nthat area and clamp two shaped blocks to get it back in shape. Then add the lining again.And hope it stays there .A mixture of clamps and pegs . If you compare a violin to a guitar the linings on a guitar are separated or linked.Sometimes lining blocks are miles apart . Something to try out . |
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Michael Darnton Moderator
Joined: 23 Mar 2007 Posts: 1347 Location: Chicago
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Posted: Mon Jun 16, 2025 8:42 am Post subject: |
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It's common for things to go haywire when they come apart and getting them back together can be a problem, yes.
Replacing the linings was a mistake, and I wonder what you thought was wrong with the originals. At that point you made the job much more difficult for yourself, since the linings are the primary method of holding the outline where it belongs and replacing them is a big deal. _________________ new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com
Last edited by Michael Darnton on Fri Jun 20, 2025 8:58 am; edited 1 time in total |
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catbrain Member
Joined: 22 Sep 2023 Posts: 49 Location: Greeneville TN.
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Posted: Fri Jun 20, 2025 4:49 am Post subject: lining replacement |
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the violin was buzzing violently when the G string was played. I believe after opening it up it was the bass bar loose at both ends. only held slightly right in the center.
The top side linings were all split and away from the sides. They were obviously split when they tried to bend them into the shape of the body.
I didnt want to get it all back together ad have those splintered linings buzzing too----
This was a very cheap chinese violin. Maybe a bit better than a 99 $ chinese lark---- maybe one step better. It was as much an exercise for me as anything.
i cut a set of form blocks that perfectly fit the outside of the bouts. I made them into a kind of vice that I could titened up with a wedge on one end. Once I got to compressed back to its intended width---- THEN--- i re-did the linings and left the big clamp on over night. That worked reasonably well.
not perfect though. Still had one of the corners mis-alligned by about 1 mm.
i made it just to have something to play if I sell my scratch made ones. Like a "beater" violin
everything you do you learn from. especially in violin making ! It only cost me 15$ at goodwill.
Got it back together oK. Much more solid now. Scooped off the finger board to clear the strings. ( it was actually bulged up in the center-)
Will get some strings for it in a few days and it needs 1 peg. Looks like they installed 3/4 sized pegs. I didnt have any of those on hand. Will look at music store in town for one. Will make one on the lathe if I cant find one.
I am still learning as I go-----
Tim
Michael----- you wouldnt believe how many people have said that to me over the years about all kinds of things. That seems to be the "bad-savant" part of me---  |
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John Cadd Super Member
Joined: 23 Jul 2009 Posts: 1344 Location: Hoylake
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Posted: Mon Jun 23, 2025 2:48 pm Post subject: Lining replacement |
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I use a very traditional bender with an aluminium heater .Iy`s electical with a thermostat . The main problem came with very straight grained pine /spruce type wood .I have never used that kind of wood for linings before .But today I tried my steam jet machine and it bends the wood much better and no chance of scorching .
Willow never gave me any trouble . |
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