This crack won't close!!

[Brian Stewart]

I've got an odd situation here, and I'm about at my wits end.  As you can see from the pic, this guitar came to me with a fractured headstock.  The crack is quite fine and clamps up nicely.  The problem is, it won't glue shut!

I am using CA for this.  I've used the thin Stew-Mac CA for the upper part of the crack, and I've tried both tite-bond CA and Stew-Mac's medium CA for the more open part of the crack.  The glue is wicking down into the crack all the way, but the crack is just not staying closed.

The guitar is an inexpensive Yamaha that is just a couple years old, I believe.  The crack was only hours old when I got to it.  The guitar took a dive off a stand apparently.

The titebond CA & thin Stew mac CA I have are not fresh, but I've been using them with good success on other jobs, and the medium Stew-Mac CA I opened specifically for this job. 

Is there possibly something I am overlooking with this?  Over the past couple decades I've glued up countless tight cracks and splinters on harps using off the shelf CA and can't ever remember having an issue.

I've tried to glue this crack 3 times over the last 4 days, leaving it clamped up for over 12 hours the last couple times.  It's starting to affect my sanity...

[Peter Poyser]

Brian.

Thank you for your thoughts and further information.

I based my statements guided by the Henkel Product Technical Sheets for the relevant Loctite CA Products designed for porous products. Those specifically intended for Wood.

Henkle is a Company that various Companies I have "an interest in" have many strong connections to, utilising a very great many of their Products indeed; and as a Market Leading Manufacturer in this field, quite simply, whom I naturally defaulted to.

 

 

This is from the relevant Henkel Data.

Q: Will refrigeration improve the shelf life of Loctite products?

A: The shelf life of Loctite Instant Adhesives will be improved by refrigeration prior to being opened.

Refrigeration will have minimal effect on the shelf life of our anaerobic adhesives. Refer to the package labeling for proper storage conditions.

 

Strangely, here.

Henkle doesn't actually warn against Refrigeration, suggesting only that it "will have minimal effect".

I (and others) have understood that to mean that as in the case of the Unopened Product, it may help keep it better, but will not make a substantial difference to ensuring endurance of Storage Life.

Perhaps our grasp of English is entirely failing us, or them. However, it is certainly true that their recommended Optimal Storage Temperatures for these Products does have quite strictly defined limitations.  

It would seem that if the Storage Environments Temperature is a little too extreme beyond somewhat median conditions either way, both Humidity or Condensation could thus adversely affect their later Performance.

Going by the information I have absorbed regarding this, it is not hard at all to imagine that there are very many Regions everywhere these Materials are Stored, some considerable way Above or Below the Manufacturers Recommendations.

 

 

This was the thought behind my opening statement.

"The wide ranging differences in regional environment across a huge Continent may make some real difference to different peoples experiences in regard to this matter."

Based upon my experience living in one of the most Moderate and Stable Climates, I am quite positive that both stores that resell these Products, and consumers that use them, do overwhelmingly Store them under circumstances that are far outside the Manufacturers Recommendations for Optimal Performance.

 

 

So I tend to read all these narrowing specifications as a matter of Henkel purely covering their backsides to protect themselves, against a range of unforeseeable circumstances.

And I believe this is why many people feel that Continued Storage in a Strictly Controlled Environment, a known quantity in regard to Temperature that is not varying wildly, not just from week to week, but through the course of each and every day; is a considerably better option, than the available alternatives open to them. Especially when the Manufacturer has advised doing this will have a "minimal effect", simply replacing the Product in the environment from whence they have just drawn it.

Usually, if the Glue genuinely has been affected by some form of water vapor in one way or another, its physical  appearance turns quite distinctly milky indeed, or detectably thickened and is very easily and clearly predictable to be advisably unsuitable for use.

Obviously, there are many different Brands of Glue on the Market, and I appreciate that they will not all behave the same.

Nor will their Manufacturers necessarily make the same recommendations for Storage.

 

Have you thought about using a CA Cleaning Solvent prior to Gluing?

Henkle do recommend this for certain difficult situations.

 

At least I'm glad there are no Oil Issues.

That is very Good News indeed.

 

Good Luck with the Guitar!

 

 

P

[Brian Stewart]

Peter,

I did not look at the Henkle site, although it did come up in my searches, however, it seems we are not too far off in our thinking about this matter.

I've got a little unscientific test going right now.  I glued some scraps of wood together using my fresh Stew-Mac glue & the old titebond CA.  After 1 hour of being clamped, I popped them apart with a hammer.  The titebond popped cleanly apart, while the Stew-mac stuff had more wood stay glued.  I read though, that full cure comes after 24 hours, so I am doing the test again, leaving them clamped for 24 hours.  I'm not sure this will tell me anything, but it might.

[Peter Poyser]

Brian.

I am thinking, you are absolutely on target with your thinking, it is the logical, next and best approach to take, considering where you now are with this.

In the Data Sheets I have read regarding Henkle CA Products, (which people expect to adhere instantly and often do) they make the case that Full Curing can take up to 72 Hours and advise in difficult cases, to clamp very securely and leave fully clamped allowing the Full Curing Time in order to effect a Proper Repair.

Sometimes that is really all that is needed, but will seem to be complete overkill to many.

However, that is what is in the Loctite Data.

 

"Initial cure and initial strength is reached in seconds depending on the particular instant adhesive, (between 3 and 90 seconds); final cure and final strength takes between 24 h and 72 h depending on materials, gap size and ambient conditions."

 

Heat as well as chemicals can be utilised as accelerators, but I know you will take obvious precautions if you do use such methods.  Ultra Violet Light can also assist in Curing these Chemicals so "Let there be Light!"

I thinks it's very easy in the circumstances you are in, to prematurely undo a Repair that is in the longer process of Fully Curing. I'm not at all suggesting for a moment you have done that, you are obviously dealing with an irksome problem, but I imagine that very few here have not done it, at sometime of another.  I'm sure I have.

However, you definitely seem to making headway steadily, and I do wish you all the best with it.

 

Sometimes, I have noted that the Specific Data in the Technical Sheets and what appears on the Bottles seems oddly to be quite different for the same Product. I guess that one is written by a Professional Technician, and the other by an Advertising and Marketing Consultant.

I do know that some CA Adhesive Manufacturers specifically advise against the continual repeated in and out of the Fridge for fear of condensation forming water droplets in the Bottle, as you mentioned. I and others have noted this advice, definitely appears to be Brand Specific.

In all probability based upon a proactive reaction to the warrantee issues they have had to particularly address, relative to their Main Target Markets and Consumer Base.

It's quite understandable, dependent upon the main global regions, certain Brands are focussed in.

Good Luck with this, I am strongly rooting for you to win in the end!

Some things take a little time and patience.

 

 

P

[Andrew]

Peter, do you know of anything that acts as a retarder for CA glues? I prefer a medium viscosity for gluing on nuts, but lately its been going off too fast to allow me to position the nut properly.

[Peter Poyser]

Andrew.

http://www.henkelna.com/us/content_data/168592_LT4985_Threadlocking...

This comprehensive guide will give a good clear overall appraisal of the essential factors in selecting an ideal adhesive for your singular application.  The wide range of cure times indicated in the various specific Products, is to my mind a better approach for your concerns than utilising a separate additional Product. If I may politely say so.

From your deeply concerning earlier posts it would seem you required an adhesive the breakaway torque of which does not exceed the residual integrity and sheer strength of the bolt and nuts tensile strength .

Obtaining that information is of course the other side of the coin, you may need to consider.

 

Best Wishes

 

P

[Andrew]

I should have clarified, but it's string nuts Im gluing, not nuts n bolts, but I appreciate the response.

[Brian Stewart]

Well, after multiple failed attempts, I just filled the crack with super glue without clamping and let it harden.  It looks fine, and I cannot open the crack with my dowel "lever" and slight pressure...I think it will be fine. 

I think the problem may have been outdated glue.  I did a little experiment, making 3 glue joints with 3 different glues, and letting them sit clamped overnight.  The fresh Stew-Mac CA glue joint survived a blow with the mallet...the wood failed.  The titebond branded CA glue joint popped clean...total glue joint failure.  As a sort of control, my third joint was with regular Titebond wood glue.  That joint survived as well...wood failed.

I threw the outdated titebond CA right in the trash.

[Peter Poyser]

Quote: "I threw the outdated titebond CA right in the trash."

 

That's the salient point.

I'm glad everything has come together well for your now.

 

Quote:" I should have clarified"

 

Not at all.

I misread or misremembered a post I followed some time earlier, and apologise for that.

For some reason the words "nut's fracturing" stayed with me, as we have metallurgical labs nearby and at every location where we routinely test all samples of incoming nuts and bolts until they crack, fracture, shear and break, failing completely.

It's quite common when things go wrong with a Product, for Manufactures to subsequently blame third party suppliers for the problem. However, it's my belief that on their behalf, Manufacturers should take full direct responsibility for the Consumer and themselves completely validate the quality of suppliers parts, in the most rigorous manner possible. So that was where my head was.

 

 

The other thing on a personal level is, it would not have occurred to me myself to use CA Glue for Guitar Nuts.

The problem being that the strength of bond with this type of Adhesive, is normally greater than the residual strength of the parts bonded. Under such circumstances, it would seem to me to be inevitable that some part of the Material bonded, will certainly break, before the bond itself ever does.

With a Guitar Nut which has a strong possibility of requiring replacement at some point in the Instruments life, this would seem to be an undesirable state of affairs. That the Nut Material would not come away cleanly without damage. So I would always go for an Adhesive for this application where the bonding strength of the Adhesive will always give cleanly long before the Material of the Nut, the Material of the Headstock Front Plate, and the fibrous end of the Fingerboard. All of which I would want to keep on pristine condition.

The way I see it, the Adhesive needs to be strong enough to hold this small part in place, but no more than necessary, so that eventually it comes away cleanly. So other, weaken Adhesives that are handy, or even a tiny bit of Shellac is how I would go. If I were to use CA Adhesive, as some people do and no criticism is intended. I would use just two tiny spots of it and with the uttermost discretion possible as to where I placed them.

However the reality is, I would try to avoid the possibility of future problems by plumbing for an altogether weaker alternative, which is easier, safer and future proof, with respect to my overriding concerns.

 

Just as an addendum, looking wider and deeper into the matter of Storage after opening. The advice given by Manufacturers I have encountered is not only Brand Specific, but also sometimes Product Specific too, and because of that, dependant on where you look, can seem to be somewhat complex and contradictory at times.

Because of this, I think that once you settle on an Adhesive that is ideal for you, it's worth sending an E-Mail to the Manufacturer and seeking their best advice for the Specific Product you are using and follow that, per the instructions.

I think lots of us, at various times have found this CA Glue not to perform as expected, when using it on many different tasks, and not quite known why.

I believe this thread has helped to highlight the reason.

 

Best Wishes

 

P

[Ned Knepp]

Peter, 

 I think that most of us that use CA for nuts do pretty much what you said, we use only a dot or two. On the end grain of the fingerboard it's actually not too hard to knock a nut loose. CAs sheer strength isn't really very good so giving a nut a  knock across the glue can usually get it right off.

[Peter Poyser]

Yes indeed Ned, thank you!

I've certainly knocked plenty of them off, in that manner, in my time.

However not all Nuts are of that type, or can be removed in that way, thus a methodology is needed sufficient to the task, regardless of the Design Encountered.

For instance, one might not be inclined to use CA Glue in the same manner, fitting a Thin Nut which is going to locate tightly into a narrow slot cut into the Fretboard well before its end.

Especially  one that has to be properly curved at the base precisely to the Radius of the Playing Fretboard. There are plenty of Guitars and Basses that actually require such a high degree of attention.

My personal view is that they also benefit from a concomitant degree of care in choice of Adhesive, but that's my view in regard to all Guitar Nuts anyway. As I wrote, no criticism at all is intended towards anyone who takes a wholly different view or uses a different method.

I've merely explained clearly what my approach is, and far more importantly precisely why I do it that way. Clearly the poster I was responding to, had fallen foul of CA Glue for this application, and had encountered entirely avoidable unnecessary problems. Which is why I so carefully outlined the thinking that unpinned my approach.

Furthermore, while we are on the subject of Guitar Nuts, it's well worth highlighting the point that certain Famous Manufacturers, Glue the Nut in place when the Fingerboard is fitted to the Neck, but before the Neck is fitted to the Body. When they both finally are enjoined, much of what is mentioned above  is masked off with Tape before the Instrument receives its Finish.

Therefore, its a sensible thing to check whether the Finish, Adheres in any manner to the bottom edge of the Nut because of this. It is perfectly possible that is some cases it will require very careful scoring around, especially under the very edge of the Nut, to ensure that when the Nut is removed, possibly with a degree of force, the Finish where it meets the Nut, does not follow it, completely off from the Guitar, or crack, craze or split in any way.

It depends on the Brand of Guitar of course, and how it's been Manufactured, but its an easily overlooked issue, that can result in a whole set of, once again, entirely avoidable, completely unnecessary problems.

And I think well worth pointing out.

 

Best Wishes

 

P