How to us hide glue for attaching large plates?

[kiwigeo]

Geophysicists...a strange breed. Theyre not hard to spot in the office...they're the guys wearing bright coloured braces and a bow tie.

Theyre also the guys who promise to come out and witness a wellsite seismic survey but they end up either crashing the vehicle on the way to the rig or failing the breath test at the heliport.

But what do I know, I've only been a professor of geophysics for over twenty years, specialising in the transmission of energy through materials.

Colin

[Allen]

Yes, I read lot's about how it's not worth the bottle it comes in. But I was curious if it was because of the addition of the urea / salt to keep it liquid, or merely the fact that it's been sitting around too long before anyone gets a chance to use it.

For example, if you made up a fresh batch, and added the salt, just to get a long open time, is it going to give similar results? Or do you end up with some glop that doesn't resemble glue?

[graham mcdonald]

Yes, I read lot's about how it's not worth the bottle it comes in. But I was curious if it was because of the addition of the urea / salt to keep it liquid, or merely the fact that it's been sitting around too long before anyone gets a chance to use it.

For example, if you made up a fresh batch, and added the salt, just to get a long open time, is it going to give similar results? Or do you end up with some glop that doesn't resemble glue?

No idea, but I would be interested to know if you wanted to do the experiment

I have a reasonable idea of how Titebond and hide glue work and how and for what I can use them. There are too many other things to learn about before thinking about modifying glue. Matthew's approach to gluing large surfaces by taking off a few clamps at a time and re-heating that section has been described by other cello/bass builders. The one thing to consider is that the glue join used for attaching bowed family instrument soundboards and backs is under different tensions to a guitar, as well as being carved and subject to different stresses from strings, tailpiece etc. My main concern about this approach in animal glue for gluing a back is that it is not getting the best glue join (clamping, separating. reheating etc) This doesn't matter so much with bowed instruments as there is the expectation of at least the soundboard coming off every decade or two, and they don't want a joint that will be too hard to undo, and the stress is a sideways shear stress rather than the pulling up and away from the sides in a guitar soundboard.

There have been lots of very fine handmade guitars using Titebond, and lots using animal glue. Similarly I have played some real stinkers using both. It don't think it is the glue which is the defining difference.

cheers

graham

[Colin S]

Graham, I don't believe I mentioned Alan Carruth at all did I? I certainly never 'caverliery' dismissed him as far as I am aware? I have a lot of time for some of his stuff. Please don't read into my words statements that are not there, that achieves nothing except to generate ill-feeling.

But, if I want to discuss the acoustics of guitars then I'll go to the guys at Loughborough or Oxford University or one of the other centres where this research is taking place and rely on their computer models.

Colin

[Bob Connor]

The difference between Titebond and HHG is not rubber gaskets.

In fact it's quite minimal in the scheme of things.

Ask Wayne Henderson. (or more importantly his customers)

[Colin S]

Geophysicists...a strange breed. Theyre not hard to spot in the office...they're the guys wearing bright coloured braces and a bow tie.

Theyre also the guys who promise to come out and witness a wellsite seismic survey but they end up either crashing the vehicle on the way to the rig or failing the breath test at the heliport.

Oh, I did do my time mud-logging in the North sea as a post grad, I now have minions to do the menial tasks! However, until recently I did seem to spent an inordinate amount of my time on a rolling ship towing large arrays. Indeed I spent four months trolling back and forth off Sumatra in 2005, and that was on a 'dry' ship!

But my main interest is in the deep crustal structures rather than the muddy bits on top!

By the way I don't own a pair of braces, but I do have the academic geologist's grey beard. At a recent symposium, of the 24 Professors of geology present, 16 had beards!

Colin

[Kim]

By the way I don't own a pair of braces, but I do have the academic geologist's grey beard. At a recent symposium, of the 24 Professors of geology present, 16 had beards!

Colin

Why is it that I get the feeling that bit of information was the most conclusive thing to come from that symposium Colin

Gees I love you guys

Allen talks of urea being added to hide glue to extend the open time, in ye olde days they would simply piss in the pot. Seems in this thread we see that nothing has really changed that much

Cheers

Kim

[jeffhigh]

Without referring to any particular issue or person, I have to agree with Colin about the Pauedo-Science.
Too often we have very false structural or acoustic theories put forward to justify a particular method rather than real calculation or accurate testing and measurement.

[Bob Connor]

OK Bob, on your next guitar let me see you mount the back and top plates using rubber gaskets, if damping at this joint is unimportant.

I'm afraid there is a lot of mis-placed pseudo-science being applied in luthiery now, take a scientific principle, apply it to a system for which it isn't designed and doesn't fit and call it 'left brain luthiery'.

Mario is right, it's all in the details.

But what do I know, I've only been a professor of geophysics for over twenty years, specialising in the transmission of energy through materials.

Colin

Mario has stated that this is a joint that hot hide glue is not particularly perfect for.(he also states that he reserves the right to change his mind on a daily basis )

I'm still of the opinion that it really doesn't matter whether you you use HHG or Titebond for this joint.

[graham mcdonald]

Colin,
My apologies for mis-reading your intentions. It was just your comment after Bob's mention of Al's corker guitar. I totally agree with your comments about 'pseudo-science' and I often get frustrated by people on forums who claim folklore as scientific fact, such as:

"The advantage for the luthier of using either HHG or Fish glue over Titebond or the other aliphatic resins is that because HHG and Fish are gelatin based glues they form hard crystal structures on dryng which are relatively non-damping compared to titebond."

May I enquire how "relatively non-damping"?

cheers

[Dominic]

I agree about the pseudo science. When I first started out I poured over the forums looking for answers and sometimes find 'belief' has replaced hard nosed analysis. This even occurs when people talk about geometry which I am sorry, but in anything mathematical there is only one answer.

To really test whether HHG or TB was better would require a level of control over your building that I don't think can be got from using organic material like wood. You can never be sure what you are observing.

It is likely that as peoples skills progress and they choose to explore alternatives like HHG it is their building techniques that are getting better but the glue gets the credit. Hence the pseudo conclusions.

Anyway, HHG stinks to me and that greasy smell stays up my nose for ages after using it. Therefore it must not work (my own pseud science)
Dom

[sebastiaan56]

Anyway, HHG stinks to me and that greasy smell stays up my nose for ages after using it. Therefore it must not work (my own pseud science)

personally Im usually the cause of the stink when I use HHG, or Titebond or epoxy or... or...

Seriously folks, how do you get a joint to fibre tear with HHG?

[Allen]

Dom, have you ever used the Ultra High Clarity glue from "Tools for Working With Wood"?

It's got bugger all smell, and doesn't even have much of a taste. Yes, I tried it out. If you want I can send you a sample. I bought 5 lbs. and it's going to last me years and years.

[James Mc]

Some of the old guys at furniture restoration mob I worked for would use urea in the HHG when they were doing inlay work on tabletops etc (the owner discouraged them from peeing in their glue pots) but it was never used where joint strength was needed.

On the issue of sound and vibration transmission and how it impacts on the sound of a guitar, well my belief ‘as a rank amateur’ is that in isolation it probably wouldn’t make a lot of difference. That said it doesn’t take much to change the sound of a guitar, the best example I can think of is the noticeable difference you get when you replace the plastic nut and saddle on a cheap guitar with a bone set. I suspect the cumulative impacts of a lot of small things that wouldn’t make much difference individually would make an appreciable difference on the sound of the end product.

[Dave White]

What's the current status of science/engineering on the theoretical ability of a bumble bee to fly?

I don't believe that anybody can really understand and model just what is going on in an acoustic guitar made of wood played by a "human bean" as the BFG would say. The best you can get are approximations and simplifications and given the subtleties and complexities of the real thing this can be worse than useless and sometimes misleading eg Heimholz effects are based on spherical containers, or that the guitar is like a hi-fi speaker.

It fascinates me that science and religion are at each others throats so often as at their core they are the same - based on beliefs that can't be definitively proved (at least that was the case with Pure Mathematics when I studied it at Cambridge back in the early 1970's).

Intuition shouldn't be lightly dismissed just because science doesn't "understand it". The human brain is a powerful thing and sometimes the way you think, react and believe things will have a profound impact on the end result.

Which brings me to the point of this thread - hide glue. Like Dominic I used to think that the switch from alphatic to hhg coincided with the learning curve progress of the builder, but with the first guitar I used hhg for the bracing and bridge I "heard" a step change in tone. Whether it's psycho-acoustics or not my building progressed in leaps and bounds from that point on. It also took another leap when Colin kindly sent me some fish glue. Now if I have to use titebond it's such messy stuff to use and clean up that I slip back into "negative mind set" again - worse still when I have to use epoxy. The fact that I intuitively believe it contributes makes it self fulfilling.

Al C's favourite saying is : "As Feynman said: "The easiest person for you to fool is yourself"". Just to be controversial - as you like that stuff in Oz if only to shoot down pompous old fart Pom builders like me - taking lots of measurements of simple things as you build guitars might not actually tell you much beyond the basics that the right linkage of brain hands and intuition and curiosity that certain people naturally have, and sometimes may actually stop you moving into areas of building that give "interesting" results.

Who's fooling who I ask?

[Colin S]

Colin,
My apologies for mis-reading your intentions. It was just your comment after Bob's mention of Al's corker guitar. I totally agree with your comments about 'pseudo-science' and I often get frustrated by people on forums who claim folklore as scientific fact, such as:

"The advantage for the luthier of using either HHG or Fish glue over Titebond or the other aliphatic resins is that because HHG and Fish are gelatin based glues they form hard crystal structures on dryng which are relatively non-damping compared to titebond."

May I enquire how "relatively non-damping"?

cheers

Graham you obviously have a problem with etiquette and good manners, or it just might be that you just don't like me. But you are exceptionally rude and quite frankly obnoxious in your way of communicating on this forum.

Some time ago at my University we did a lot of testing on the damping properties of a lot of materials used in guitar building including various wood types and the glue joints used. This was all posted on the OLF. and yes though the effect was small there was a greater energy loss through Titebond and other aliphatic glue joints than through Hide and fish glue. I don't deal in folklore.

Bob, I shan't be posting here anymore, I'm afraid that I find some of the company not to my taste.

Colin

[Kim]

It is sad when such a simple disagreement between grown men can end up so negative. For me the whole point of a forum is to exchange ideas and learn from each other. Part of that process must be to have those ideas challenged or there is simple no point to the conversation.

I am not pointing the finger at any individual here, I just think it would be better for all if we could accept that not everyone is going to see thing our way every time we type something. If we keep our egos at bay, maybe, just maybe we could simply move on rather than allow things to degrade as they have here. Quite frankly I do not see any reason at all in what I have read above for any member to leave this forum. It is just and exchange and nothing more, no pistols at dawn required really.

Cheers

Kim

[Dominic]

Come on Colin, if an Aussie wants to be rude and obnoxious it would be much more obvious and also quite funny. This is just a discussion, not a punch up.
Peace bothers and sisters
Dom

[matthew]

I didn't read Graham's reply as rude in the slightest. I think Colin mis-understood the tone of his post. This is one of the problems where we can't see the twinkle in the eye.

When Bob posted :
"According to Al Carruth, whose research I follow with great interest, very little string energy gets transmitted to the back through the sides."

and I replied:
"OK, so when you strike a chord and you feel the body vibrating against your tum ... where do those vibrations come from? Last nights dinner??"

Bob could have taken that as me taking a swipe at him I suppose. Certainly I was challenging something he posted. But he got the tongue-in-cheek in my post and didn't take it personally, explained the science behind the claim, and on we went ...

All Graham was doing was challenging an odd statement Colin made. "relatively non-damping" just begs the question, I reckon!

So Colin, please reconsider, stay with us.

[Allen]

It's just glue people.

:bh

[Dominic]

Allen, sure a little sample would be much appreciated. I've not heard of Tools for Working With Wood before. Is it local or in the US?
Cheers
Dom

[Lillian]

Tools for Working Wood

Now it works.

They've got a glue pot that I'm interested in. Its about as expensive as the ones from LMI, but I like the fact its has a copper pan.

[Allen]

If your looking for some really good glue, then the 192 high clarity glue is just so much better than the stuff I got from Gilet Guitars. Problem is that the postage ends up being as much as the glue, so buy the 5 lb. bag and be done with it. Enough to last most people the rest of their luthier life.

[sebastiaan56]

Is this a potential group buy item?

Sebastiaan

[Allen]

It would be a good option, but I'm set for quite a while, so I'll let someone else who wants to get some glue set that up.

They were good to deal with, and packaged arrived via USPS in the usual time in case your interested. I think the 5 lbs came to around $75 AU with the shipping. That would have been well over a year ago now, so the $AU was in the low to mid 70's back then.