|  | 
08-22-2005, 11:44 PM
| | Registered User | | Join Date: Apr 2002 Location: Ontario | | | So, you guys are hip to the use of hide glue, I've got a question A friend of mine needs to repair the headstock on a Yamaha acoustic guitar. What weight hide glue should he use, and beyond not applying too thickly, what other things should he know before using it?
Sign in to disble this ad
__________________ Quote: |
Originally Posted by HollowBassman Doesn't she know that they're not really people until the age of about three? | | 
08-23-2005, 09:02 AM
| | Supporting Member/Luthier | | Join Date: Jan 2002 Location: Cincinnati, Ohio | | | Mix the dry hide glue:water 1:1.5 You want the glue to be the consistency of free-flowing honey. Not drippy, like water, and not thick and coagulated, like snot. Somewhere in-between... it is easier to add a >>little<< water to make it thinner than adding more dry glue to make it thicker.
Do two dry-runs of the clamping method. You don't have much time once the glue is spread onto the wood.
As a little lesson, put a drop or two of glue on your first finger. Now lightly make a pinching motion using your first finger and thumb. While watching a second-hand on a wall clock, see how long it takes for the glue to grab and become really sticky in your fingers. This will give you a clear idea of just how long you have to get all your clamps in order. The glue will slowly become stringy, like taffy...
Once everything is clamped up, go over the squeeze-out with a hot-water-damped paper towel. It is easier to remove excess wet glue than dried glue.
g/l. | 
08-23-2005, 10:04 AM
|  | Proprietor, Upton Bass String Instrument Co. | | Join Date: Oct 2002 Location: Boston, MA 617-236-7706 | | The higher the molecular weight the higher the strength BUT I would think more on the terms of a good clean joint and exactly as Nick stated the right mix and dry run. The best glue in the world means nothing with bad application and fit.
Prep, prep, prep!!!!!
Without seeing the repair and being able to judge the break and wood, some form of reinforcement may be needed, not ironwork  BUT it's a GEETAR....is that acceptable? Whats the neck made of? If its Mahogany I would worry about the wood around the break more. (micro-cracks)
When you make the glue and "melt" the water and granuals together, take it off the heat, close the bottle, and run it under cold water until you achieve a true solid gel (or put it in the fridge for a bit even 24hrs). Once this is done, then go back and re-heat, and use the liquid glue. Glue is strongest AFTER the first gel cycle.
A LITTLE heat on both pieces will lengthen the working time (for small work, holding the pieces to be glued under a high watt bulb can be enough). Also, we think about climate in regards to clamping time. In the winter the room temp and humidity require a bit less time under pressure.
A friend....? Come on you can admit you have a guitar..  | 
08-23-2005, 10:39 AM
| | Registered User | | Join Date: Apr 2003 Location: Oshawa, Ontario, Canada | | | "Hot" glue From what I read the consensus of opinion on temperature seems to be around 140 degrees F. I recently put together a home- made glue pot using a clothes iron for the heat source. I found that mug warmers and coffee makers only get to about 120 degrees, not quite hot enough. The iron will get much hotter than that, so it's best to monitor the glue temperature with a stick type thermometer. Put the glue in a small glass jar inside a larger vessel partly filled with water, kind of a double boiler sorta thang. Heats the glue more evenly, and gives you a ready source of hot water for thinning the glue or cleanup. All this, of course, in the absence of a proper glue pot as used by the pro's.
__________________
There are 10 kinds of people in the world, those who understand binary and those who don't.
| 
08-23-2005, 11:06 AM
|  | Official Forum Flunkee | | Join Date: Mar 2004 Location: San Francisco, CA | | Quote: |
Originally Posted by uptonbass Without seeing the repair and being able to judge the break and wood, some form of reinforcement may be needed, not ironwork  BUT it's a GEETAR....is that acceptable? Whats the neck made of? If its Mahogany I would worry about the wood around the break more. (micro-cracks) | I've seen headstocks that have totally snapped off from the neck be reinforced with metal tabs or rods or somesuch. Come to think of it, some EB makes put graphite rods in their necks when first built. Doesn't KSB do this? Ken? Anyways, I don't think it's a job for the amateur. Although Dan Erlewine puts out some great geeetar luthier books and demonstrates this in some of them. | 
08-23-2005, 12:54 PM
| | | | I fix 3 or 4 headstocks a month. I don't use metal or reinforcing plates. They aren't needed and don't hold up. Serious breaks that have missing wood can need some wood grafting. If that is needed an experienced hand is suggested. To easy to mess it up and not be able to undo the mess.
I use hide glue on those repairs 90% of the time. What's already been said about it's use is great. Prep is everything. Complex breaks can require complex clamping methods. If the fingerboard is affected by the break be sure to maintain the parallel relationship between the neck and fingerboard with your clamping mechanism. Take steps also that the peghead angle is maintained by your clamping mechanism.
It's easy to miss something in that 3 dimensional relationship that causes misalignment of the fingerboard/peghead. This makes the fretwork and fingerboard come out funny and you can chase your tail getting it to play right.
The finish touchup is the final sealer to keep the joint from being compromised over time. That's a whole nuther subject.
On cheaper guitars epoxy fixes can be better because the finish touchup is incorporated into the squeeze out.
But these are guitar issues. Why am I talking about this here?
Sorry... | 
08-23-2005, 01:12 PM
| | Registered User | | Join Date: Apr 2003 Location: Oshawa, Ontario, Canada | | Quote: |
Originally Posted by Auntfroggy But these are guitar issues. Why am I talking about this here?
Sorry... | S'okay. Clamping and alignment issues are universal. So is finish touchup. Slabs are sorta related, like guitars they also have pegheads and frets, whatever they are...
__________________
There are 10 kinds of people in the world, those who understand binary and those who don't.
| 
08-23-2005, 02:41 PM
| | | Quote: |
Originally Posted by Eric Jackson S'okay. Clamping and alignment issues are universal. So is finish touchup. Slabs are sorta related, like guitars they also have pegheads and frets, whatever they are... | Ok then. Here's a pic of a peghead break I'm doing today. This is a dry clamp run. I may mess with it a time or two before I glue it up but this gives you an idea of what I mean. http://www.fretshop.com/HeadstockBreak106.jpg.jpg
The main clamp is the cam clamp. The others are supportive and not real tight. This particular break has no fingerboard implications. The neck pitch is maintained by the wedge and block structure. I will probably use wax paper as a release agent for the clamp face before I glue it. | 
08-23-2005, 09:11 PM
| | Supporting Member/Luthier | | Join Date: Jan 2002 Location: Cincinnati, Ohio | | ...aren't quick-grips the bomb?  | 
08-23-2005, 09:17 PM
| | | Quote: |
Originally Posted by nicklloyd ...aren't quick-grips the bomb?  | The best. Can't have enough. I have them hanging everywhere. | | Thread Tools | Search this Thread | | | |
Posting Rules
| You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |