Official Luthiers Forum!
http://w-ww.luthiersforum.com/forum/

CA on Coco?
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=3641		 Page 1 of 1
Author:  Steve Kinnaird [ Thu Oct 27, 2005 2:51 pm ]
Post subject: 
Skip's thread got me wondering: is anyone gluing coco together with CA glue? I've done this on a small scale, but not in (guitar) assembly work.
I did make a square once using coco for the handle, and brass for the blade. The first step called for gluing in the blade to the handle with CA. It shifted about 1 degree on me, then set up. Attempteing to realign the blade, I mounted the handle in a vise, then beat the blade with a hammer. To no avail. It would not budge. I was quite impressed with the strength of the bond! Had to heat the blade up with a torch to break down the glue joint so as to redo (at this point replace) the blade.

This makes me wonder--why not CA glue on Cocobolo?

Steve
Author:  Skip Beach [ Thu Oct 27, 2005 4:07 pm ]
Post subject: 
Hi Steve,

I read somewhere (maybe it's true) that the expected life of a CA bond is around 15 years. Supposedly after that time, the bond severely weakens as the stuff deteriorates.

Please note: This is hearsay! I have done no research on this. It may have been in the MIMF library, but I'm not sure.

It seems nothing's perfect

Skip

Edit:

Here's the quote from the MIMF library (the names have been changed to protect the innocent) Lance, if you need to delete this due to legal issues that's fine.

Nicholas Bxxxxx - 12:02am Mar 28, 1998
An "objects conservator" at the US Park Service Harper's Ferry facility told me that the CA glues have a life of fifteen years. They were initially used to put together glass and ceramic artifacts, but after fifteen years the artifacts would simply fall apart. Now, if that's the life span of a glue joint in a climate-controlled museum, what about the peghead inlay on a banjo baking in parking lot jam in July? Skip Beach38653.0637268519
Author:  John Kinnaird [ Thu Oct 27, 2005 9:30 pm ]
Post subject: 
Lots of folks are using CA to put on binding and of course do inlay fill. Fifteen years eh. That may be longer than Titebond sticks to Cocobolo. I have had braces pop up on a guitar I was making out of Cocobolo that I glued down with LMI white glue. I reglued it with CA and it stuck hard and fast.

I always heard that CA was developed to do stichless medical wound repairs in combat situations. I can vouch for the fact that it will last for at least a week on skin. But its water resistance is not very high.
Author:  Dave-SKG [ Fri Oct 28, 2005 12:15 am ]
Post subject: 
I did a repair...hairline crack on coco body. Waist thru Upper bout. Wicked in thin. Sanded the inside clean, outside flush and FP'd the area (the body was FP'd as it's finish) and the hairline was gone/repaired.
Author:  LanceK [ Fri Oct 28, 2005 12:24 am ]
Post subject: 
A while back I was talking about adhesion issues while using Coco with a very well known classical/steel builder. His practice is to bake the back plates in the oven at 250 for a few hours, then when you bend the sides, do the same in the bender. He said “You can use plain old Elmer’s glue then" and your braces wont pop off. It’s a matter of getting the resins and oils out.
I have never done this, although I have 2 coco commissions on the books and I plan to try it on them. Like you John, I have been using LMI white, and have had to reglue or remove and replace back braces because they lifted.

Author:  Skip Beach [ Fri Oct 28, 2005 1:02 am ]
Post subject: 
If you pros are having problems with braces popping loose or lifting on Cocobolo using LMI white glue, then that settles it - I'm spending the $23 plus shipping for the Smith & Co. All Wood Epoxy! Even though it's epoxy, supposedly it is pretty hard & a bit less flexible than many standard epoxys. So I guess it would not be totally unsuitable for back braces, linings & end blocks.

Hopefully that CA comment from way back in 1998 is just BS - especially since no one else has heard this from any other source. Scary thought however.

Skip
Author:  LanceK [ Fri Oct 28, 2005 1:09 am ]
Post subject: 
Skip - the funny thing was, the conversation I had was in regards to using Epoxy for gluing down braces and how unnecessary it was. This guy has been building for well over 25 years. I would name him, but our conversation was had over email.
Author:  John Kinnaird [ Fri Oct 28, 2005 1:30 am ]
Post subject: 
I know of a VERY will know luthier who said that they used the LMI on cocobolo and then if and when braces poped loose they just reglued with more LMI. I think that is risky behavior.

The Smith's All wood glue is great! It really is brittle when cured, (lots more brittle than titebond so I think less apt to absorb vibrations) it does seem to adhere to cocobolo well and I have never had any adhesion problems whatsoever. It is a little messy on the cleanup. I have taken to using alcohol on a rag to get the final, and for me inevitable, smear off the wood. other than that I recommend it.
Author:  rlabbe [ Fri Oct 28, 2005 3:30 am ]
Post subject: 
I don't know about Coco, but as far as CA goes Larrivee uses (or used) CA to glue back seams together according to an interview in and old issue of GAL. This was for all backs, not coco. Do his back seams have a reputation for opening up? If not, I would assume it is safe. I also know that the builder David Schramm uses CA to glue his back seams. I remember he took some heat for it on the MIMF forum, but it seems like the guys who are out there doing it for a living have no problem using CA glue for this purpose.

Whether it works for cocobolo, I have no idea, being allergic to the stuff (coco).
Author:  LanceK [ Fri Oct 28, 2005 7:12 am ]
Post subject: 
"I know of a VERY will know luthier who said that they used the LMI on cocobolo and then if and when braces poped loose they just reglued with more LMI." I think that is risky behavior.

John - were you quoting me? Or is this another person?
Author:  Steve Kinnaird [ Fri Oct 28, 2005 7:27 am ]
Post subject: 
Thanks for the input guys. But it doesn't sound like we're coming to a consensus, yet.
Any other opinions out there?

SteveSteve Kinnaird38653.889849537
Author:  JBreault [ Fri Oct 28, 2005 7:47 am ]
Post subject: 
Didn't someone on this forum make a guitar only using CA? I remember him saying that it held together great and is still strumming. I have no personal experience with it.
Author:  RussellR [ Fri Oct 28, 2005 8:49 am ]
Post subject: 
Yes in Was Kevin Gallagher he had to do it as someone was in a real hurry for it.
Author:  Don A [ Fri Oct 28, 2005 10:07 am ]
Post subject: 
I believe John Mayes did also on his 4 day build.
Author:  Don Williams [ Fri Oct 28, 2005 10:27 am ]
Post subject: 
I would certainly like to here from the horse's mouth about the limited lifetime of CA. If this has any merit, we're best to leave it out of our builds, regardless of how easy it is to use for some things. I think I would trust polyurethane glue more. One thing's for sure...you can't use Titebond on a cocobolo back seam. I've heard lots of stories about the glue creeping and the center seam causing a finish nightmare. My experience was the same as that on the first coco back. The second one was glued up with something else, and has not caused problems.
I just can't remember what it was.

D'Oh!
Author:  Steve Kinnaird [ Fri Oct 28, 2005 12:22 pm ]
Post subject: 
C'mon Don, search those records and give us the story.

Steve
Author:  Dave Rector [ Fri Oct 28, 2005 11:24 pm ]
Post subject: 
[QUOTE=Don Williams] I've heard lots of stories about the glue creeping and the center seam causing a finish nightmare. [/QUOTE]

I have one in the shop right now with the same problem. Still unsure what to do with it.
Author:  John Kinnaird [ Sun Oct 30, 2005 10:31 am ]
Post subject: 


Lance, I was not thinking of you when I made that statement. I was not thinking nor quoting anybody on this forum. However, even though not on this forum, the person I am quoting is a very well respected builder. I thought this was just an interesting way to see if the glue was going to work or not.John Kinnaird38655.7742361111
Author:  John Mayes [ Mon Oct 31, 2005 4:24 pm ]
Post subject: 
[QUOTE=Don A] I believe John Mayes did also on his 4 day build.[/
QUOTE]

I actually used nothing but hide glue on that guitar. Wanted to see if it
made a really noticeable difference...... it didn't








John Mayes38657.0182638889
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/