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Thin CA or hide glue?
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=29974		 Page 1 of 1
Author:  Tai Fu [ Thu Nov 18, 2010 8:53 pm ]
Post subject:  Thin CA or hide glue?
I have another Gibson Les Paul custom to fix, same peghead break (why do all these Les Paul break in the same way??) except this time its a small crack that I can barely pry open. Do you think I should attempt to wick thin CA into the crack and clamp it up, or should I go ahead and use hide glue?

Attachment:
crack.jpg
Author:  ChuckH [ Thu Nov 18, 2010 9:01 pm ]
Post subject:  Re: Thin CA or hide glue?
Hi Tai,
Haven't seen you on here in a minute. I'm always partial to hide glue. Although, I know a feller what would pour in some titebond in that crack and use compressed air to push it way back in the crevasses. You can use those cans of air with the little straw that you use to dust off keyboards and such if you ain't got no air compressor. Then just clamp the dickens out of it.

Hutch
Author:  Tai Fu [ Thu Nov 18, 2010 9:09 pm ]
Post subject:  Re: Thin CA or hide glue?
Yea, I have been busy trying to go to Germany and right now I am not having much success. In any case I got rid of all the big tools like air compressors because those don't move so well... I am thinking of using one of those blow bulbs that people use to clean cameras to blow glue deeper into the crevice but the crack doesn't look like it's going to open up enough to allow me to get glue into it... but water thin CA will wick in easily. I am lost on how to mix hide glue properly though because I had instances where the glue lets go for unknown reason... don't know if it's due to an improper mix ratio. How can I mix them properly if I don't have access to precision scales?
Author:  meddlingfool [ Thu Nov 18, 2010 9:12 pm ]
Post subject:  Re: Thin CA or hide glue?
One advantage of HHG to consider might be cleanup, being that you you can just wash off the excess with hot water once the clamps are off. Same with watered down wood glue. CA is a little tougher to deal with. But I'm no repair guru so see what others have to say...
Author:  Tai Fu [ Thu Nov 18, 2010 11:51 pm ]
Post subject:  Re: Thin CA or hide glue?
Any tips on how to properly measure hide glue without a precision scale?
Author:  fric [ Fri Nov 19, 2010 1:39 am ]
Post subject:  Re: Thin CA or hide glue?
hi,

almost the same problem I solve with epoxy.
Epoxy I use has 1h open time and very low viskosity so just one drop of epoxy on the crack and you can see how it easy penetrate to crack


fric
Author:  jfmckenna [ Fri Nov 19, 2010 9:38 am ]
Post subject:  Re: Thin CA or hide glue?
I almost always use Titebond for those repairs. So easy to clean up and leaves no mess, that crack you can almost make it look like it was never broken with no extra finishing work. If you flush the crack with a little water it will draw the Titebond in. The air trick is an excellent idea, thanks for that tip, I will always use that in the future now.

I think the neck angle has a lot to do with why Les Pauls and SG's always crack there.
Author:  David Newton [ Fri Nov 19, 2010 11:26 am ]
Post subject:  Re: Thin CA or hide glue?
In 30 years of repairs I have literally done 100 or more Gibson headstock cracks exactly like that, Titebond has never failed.
Flood the crack area and "work" the joint open and shut slightly, it will "pump" the glue into the crack. As mentioned, cleanup is a snap.
Not something I would want to do with CA glue, with the danger to the finish.

Funny story ( I can't help myself ) a guy brought his new Les Paul in with this crack and I made him happy. One week later his band-mate with the exact same break on his SG.
Author:  Howard Klepper [ Fri Nov 19, 2010 2:18 pm ]
Post subject:  Re: Thin CA or hide glue?
I always start by taking the tuners off.

CA will mess up the finish.
Author:  John Hale [ Sat Nov 20, 2010 6:34 am ]
Post subject:  Re: Thin CA or hide glue?
I've only done 4 of these now and I use Cascamite (urea formaldehyde resin) for fresh breaks and epoxy if I can't be sure to have gotten all the old glue out. I damp the joint when not using epoxy to help the glue wick into the joint and keep forcing it in with a brush and gently work the joint open and closed to get and much spread of the glue as possible before clamping. Possibly not the accepted methods but it's worked for me!
Author:  Alexandru Marian [ Sat Nov 20, 2010 7:07 am ]
Post subject:  Re: Thin CA or hide glue?
You can try fish glue as well. Endless open time so you have enough time to work it in. Clamp it for 12h. Once it is dry it is about identical to hide. It is not the end of the world if it doesn't reach the very end of the crack, some glue will travel when clamped plus that maybe most of the stress is at the opening.
Author:  bluescreek [ Sat Nov 20, 2010 7:23 am ]
Post subject:  Re: Thin CA or hide glue?
I have used tite bond for a few of these repairs . All held . I did apply it as deep as I could and kept working the joint till I felt it went in deep enough. I think HHG would be fine also . You can make that flow easy enough
john
Author:  Tai Fu [ Sat Nov 20, 2010 7:39 am ]
Post subject:  Re: Thin CA or hide glue?
I think I am still leaning towards hide though... because dried hide glue cleans up really well with lukewarm water, whereas titebond refuses to dissolve in water once dried. I am digging around for the clamping caul I used for my last les paul fix, but I only found one piece. The other piece (the more critical piece which is a board with one edge rounded to conform with the neck back profile, with cork attached to it) is nowhere to be found...

Plus I lost my thermometer thus I have no way of regulating water temperature to ensure the hide doesn't cook...
Author:  Alexandru Marian [ Sat Nov 20, 2010 7:52 am ]
Post subject:  Re: Thin CA or hide glue?
I don't think they ever used thermometers in the past. It is like 4000 years - no thermometer - a few decades - thermometer. Hmmmm. I do use one but I often stick my finger in the glue trying to learn to feel it. At over 60 degrees you can't really hold it in for too long, it is burning HOT. Otherwise they would call it warm glue instead of hot glue :) So I would say that if it feels just very warm, or acceptably hot, it is not hot enough. At the other end, "cooking" at a very high temperature is almost acceptable as long as long as you are not doing it for long periods (several hours). It is anyway pretty difficult to really "cook" it as in approaching boiling temp for the water jacket. We are worrying too much really.
Author:  Tai Fu [ Sat Nov 20, 2010 8:15 am ]
Post subject:  Re: Thin CA or hide glue?
Well, it's done, just have to cross my fingers that it will hold.

I used one teaspoon of hide glue, 2 teaspoon of water (I added another teaspoon because it felt a little too thick) and heated water in a water heater up until the display says "70 degrees C", then dunked the pot of hide glue into the hot water. I made a thin pipette by pulling on it with a plier and put as much glue into the crack as I could and forcing it open at the same time so I can get glue in. Then I just opened and closed the crack (which is possible by varying the amount of pressure I put on the headstock) and it caused the glue to get pumped into the crack. Anyways, now I clamped it up. I will worry about the excess later on (which should not be a problem... will mop up with a lukewarm towel) then proceed to repair the finish.

I wonder if I were to build a Gibson style guitar what can I do to avoid this kind of damage? Should I just drill holes inside the joint, and epoxy threaded rods into the hole in order to reinforce the joint?
Author:  jfmckenna [ Sat Nov 20, 2010 8:21 am ]
Post subject:  Re: Thin CA or hide glue?
Tai Fu wrote:
Well, it's done, just have to cross my fingers that it will hold.

I used one teaspoon of hide glue, 2 teaspoon of water (I added another teaspoon because it felt a little too thick) and heated water in a water heater up until the display says "70 degrees C", then dunked the pot of hide glue into the hot water. I made a thin pipette by pulling on it with a plier and put as much glue into the crack as I could and forcing it open at the same time so I can get glue in. Then I just opened and closed the crack (which is possible by varying the amount of pressure I put on the headstock) and it caused the glue to get pumped into the crack. Anyways, now I clamped it up. I will worry about the excess later on (which should not be a problem... will mop up with a lukewarm towel) then proceed to repair the finish.

I wonder if I were to build a Gibson style guitar what can I do to avoid this kind of damage? Should I just drill holes inside the joint, and epoxy threaded rods into the hole in order to reinforce the joint?

Carbon fiber maybe?
Author:  Alexandru Marian [ Sat Nov 20, 2010 8:25 am ]
Post subject:  Re: Thin CA or hide glue?
Scarf joint, face and back plates of hardwood...Bombproof sandwich!
Author:  herry tze [ Sat Nov 20, 2010 10:42 am ]
Post subject:  Re: Thin CA or hide glue?
hello Tai Fu.. ni hao ma...
some time ago I got a recipe for concocting hideglue
1. Another mistake is to use a glue pot that gets the glue too warm; that means, over 150d.F
140 degrees F is about right.
2. My current glue is (Milligan & Higgins) 192 gram strength high clarity. It's water-clear
when mixed, and I useabout 1.9 parts water to 1 part glue by weight.)
3. Mix dry glue with cold water and allow water to be fully absorbed (about an hour.) Heat in
glue pot or double boiler 145°F and stir gently until mixture is smooth and clear. Glue
must be heated (145°) for use, but may be kept for several weeks covered in refrigerator.
Discard if you notice foul odor, mold or any other contamination. To avoid loss of
strength, do not heat glue for long periods, or above 145°.

Proportions of glue and water will vary with the gram strength of the glue. Practice with each new shipment of dry glue to obtain the ideal mixture, and mix by weight, not volume for the most consistent results. Most of us like the glue thin enough to just run off the brush when dipped into the heated mixture.
Author:  Tai Fu [ Sat Nov 20, 2010 10:56 am ]
Post subject:  Re: Thin CA or hide glue?
The question is, how do I measure glue by weight when I don't have a precision scale? Water is easy enough (water is always one gram per mL) but the glue is the problem.

Are the proportions critical, like if I deviate by a tiny amount will I get glue that won't work, or is there an acceptable margin of error?
Author:  herry tze [ Sat Nov 20, 2010 11:20 am ]
Post subject:  Re: Thin CA or hide glue?
Tai Fu,...
this is the answer if you don't have scale
I just weigh for you with comparison water 1.9 : 1 hideglue (dry) here it is in small qty.
6 spoonfull water (almost 40grm) : 2 spoonfull dry hide glue (20grm)
I think if too much water your glue more dilute and maybe less sticky...
Author:  Mike Lindstrom [ Sat Nov 20, 2010 11:31 am ]
Post subject:  Re: Thin CA or hide glue?
I've used hide glue a little, but I've read about it a lot. The web is full of people telling uptight engineer types to lighten up and just glue some stuff. Hide glue has been used for thousands of years. Most of that time, people did not have digital feedback on their glue pots and it worked fine. Most people would fire it up in the morning and add water throughout the day as they worked.

While there are certainly people who throw it away if they get over 152.7 degrees, lots and lots of people don't worry about it. Some in the middle say you can heat it significantly more if you need it thinner, but then throw out the remainder.

I had a small hot pot, I found the thermostat was not very sensitive and the temperature of the water bath swung 130-170+F, and got rid of it, but a lot of guys use this exact model and they seem to know what they're doing.

What's working for me now is a "Little Dipper" crock pot with a fixed temperature. Temperature control is lid on or lid off.

Mike
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