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Glues and their diffrences ! Explain please !
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Author:  WudWerkr [ Mon Dec 27, 2010 9:45 am ]
Post subject:  Glues and their diffrences ! Explain please !
I have been comming here for a bit over a year . I have read alot about many things and learned a little . One thing I am curious about is the various Glues people discuss .

Thus far I have used titebond orig. It seems to be working good , I do use some ca in emergency situations .

However , I know there are also " fish glue , hot hide glue" , and others that are talked about. Would some one be willing to kinda summ up in laymans terms the best glues for uses in various areas?

I bit of a " Sticky tutorial" if you will ? laughing6-hehe

Uppsides , down sides, etc:

Thanks cause idunno
Author:  DennisK [ Mon Dec 27, 2010 8:44 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
Well, I was going to do a big list of pros and cons of various glues, but I got bored after hide glue, and it has the most interesting properties anyway.

I'm no expert, but here are my uses:
Hide glue is the default for structural joints, although I substitute LMI white sometimes if I'm too lazy to heat it up.
LMI white for inlays.
CA for sticking bits of shell together before inlaying. Don't like risking staining the wood by using it to glue the inlays in.

I think Titebond behaves pretty similarly to LMI white, although maybe not quite as hard and cold-creep resistant, and maybe a bit longer open time.

I don't currently use epoxy, but it does have a lot of good properties as well. The glue itself is strong, so a tight joint isn't as critical as other glues. Sticks to oily woods like cocobolo. Long open time. Not water based... flatsawn fingerboards and bridges can cause trouble when gluing, due to absorbing water out of the glue and warping. Can cause a bad joint due to the contact surface no longer being flat, and for fingerboards, pull the neck out of shape after it's dry. Unfortunately, fingerboards and bridges are some of the more likely things to need ungluing/regluing later in the instruments life, and epoxy is not good for that.

And here are the pros and cons on hide glue...
Pro:
- Super strong with a good joint
- Heat resistant unless wet
- Water resistant unless heated
- Re-melts and sticks to itself... no need to scrape to bare wood when reassembling a joint (eg. gluing the top back on a violin after having it opened up). Also very convenient for noobs who screw up clamping operations frequently, because you can just slop some fresh glue and try again rather than being on a doomsday timer if your glue gets too dry before you get it clamped properly.
- Fast tack, especially good for gluing tentellones
- Enables rubbed joints. Essentially auto-vacuum clamping by squeezing glue out of the joint while the glue cools and thickens, to where it won't suck back in when you let go.
- Easy squeeze-out cleanup after it gels. Most of the time just scraping with a fingernail gets it all. Paper towel dipped in warm water will get the rest.
- Stays fresh indefinitely in granulated form. No need to frequently buy new like other glues.
- People pay more for it because it has a mystique surrounding it :lol:
- Dries crystalline hard. This is a lot of the mystique, as it may transfer vibration better than softer glues.
- Zero cold-creep

Con:
- It's a pain to heat up
- It's kind of messy. Super sticky when it gets on your fingers, although it washes right off in warm water.
- Very short open time. Must warm parts before gluing or it will gel on contact.
- Brittle. Need a good tight joint with maximum surface contact or the glue can break.
- Although it stays fresh when dry, it can spoil once mixed with water. I keep a little bottle ready to go in the fridge all the time. To my knowledge I've never had any go bad, although I usually toss it if it's more than a month old just to be safe.
Author:  WudWerkr [ Mon Dec 27, 2010 9:34 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
Thanks for the response [:Y:] I really appreciate the insite . Ive never tried the hide glue . It may be somthing i wish to look into.

Any other takers on this subject who would like to add to this thread ? [:Y:]
Author:  Mike Lindstrom [ Mon Dec 27, 2010 9:38 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
Nothing wrong with Titebond. Many serious builders use it for everything. I used it exclusively on my first couple and started branching out. Here are some of my observations.

Fish glue has has many of the good qualities of hide glue, (dries very hard, reversible, can stick to itself...) but has a much longer open working time, making it great for glue ups that take a while. I use it for bindings. It needs much longer clamping time too. Since I work alone, it's easy enough to plan around it and let it clamp over night.

I've started using more hide glue now that I've got a system I like with the heat. I like the easy cleanup, and the claims of many that it does (or should) sound better. While learning to deal with HHG, I had the odd part just fall off a couple weeks later.

Epoxy - tox potential worries me, but a lot of guys like it for oily wood, and for fret boards. Other glues have water in them that can be absorbed into the neck or fretboard, inducing movement. What surprised me with epoxy was all the directions. I think of it as Ace Hardware, 5 minutes and you're done, but the stuff I've used needs to be pre mixed, then it needs to be spread on and soak in 30-60 minutes, then you can finally assemble and clamp up. Make sure to read the instructions before you start so you're not surprised.

LMI White - I haven't used it, but I've been told it is the best glue for invisibly gluing a crack in a top.

Titebond works fine for the most part and has the additional advantage of my being able to buy some within minutes, any time, should I run out.

Mike
Author:  Rod True [ Mon Dec 27, 2010 10:49 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
This was my response to this post back in March 2008.

There are certain parts of the guitar that you want to have different attributes such as repair-ability, creep resistant, heat resistant, plastic, elastic, rigid.

Of the glues out there, IMO there really are only a small number that are best suited for guitar building.

Hide glue and fish glue have both been proven over time to outlast any single human life cycle. They are undoubtedly the leaders in longevity. The other factors about both glues is that they cure to a rigid, glass hard state which will not creep under normal heat and humidity fluctuations. Both have some amount of water content so using them over large surfaces can induce warping. Generally heat and moisture will soften these glues and cause them to release. Places on the guitar where hide or fish glue are found is brace to plate joint, plate to rim joint, rim to tail or head block, headstock veneer and really any place two pieces of wood come together although it may not be the best glue in some areas. Some folks use these glues for pore filling too. Clean up for Hide glue is easy with a moist rag or waiting 10-15 mins and it will be hard enough to peel away the squeeze out. Clean up for fish glue can be a bit messier but a moist rag after 5 mins will get the sqeeze out taken care of. Set up time is longer and joints can be handled after a couple hours but should not be stressed for 12-24 hours.

Aliphatic Resin glues (AR glue), (titebond, probond, yellow woodworkers glue) do not cure to a glass hard, rigid state (well not when compared to hide or fish glue) they are more elastic and will creep over time when stressed or heated. Heat alone can soften these glues and cause them to release. Many builders will use an AR glue for every glue joint on the guitar although it may not be the best glue in some areas. Clean up is easy with a moist rag after a few minutes. Set up time is relativly short and joints can be handled within an hour or two.

Epoxy (there are way to many types of epoxy to try and isolate them) generally one that cures at typical room temperature over a 12-24 hour period is what is used in guitar making these days. Epoxy does not have any moisture in it which makes it the ideal glue for attaching the fretboard to the neck. No chance of warping when water is not present. Epoxy also can gap fill to a certain extent which is helpful when you need to fill gaps of course. It also won't shrink back over time. Epoxy can be softened with heat alone and it doesn't take as much heat to soften it as it would to soften an AR glue. Generally Epoxy is used for the fretboard to neck joint and in some inlay work. Sometimes it is used with an oily wood like Cocobolo to glue braces down. It's not found on very many glue joints in the guitar. More and more people are using epoxy finishing resins for pore filling. Clean up is not to easy. Best to let the glue cure fully (usually 24 hours) and cut away or sand off the sqeeze out or excess resin.

Polyurethane glue's (gorilla, titebond, Elmer's) are 100% water proof (don't have to worry about warping here either) and are non-reversible. This is the best glue IMO for making laminated necks. You don't ever want your lamination to warp due to moisture or to creep or to release because of heat. Some folks don't like the clean up but I've taken some good advise from Mario, don't touch it till it's fully cured (usually about 24 hours) and you won't get all sticky. Yes it foams and oozes everywhere but once cured, it cuts off your wood just fine. Lots of clamps and pressure is the key with Polyurethane glues. As mentioned, not many use polyurethane glues in guitar making.

CA glue (super glue, crazy glue) cures fast to a crystalline state (not sure if it's glass hard though). There's not a great amount of history with it as guitar making or wood working is concerned. It does not have a high shear strength which might be why it's not used much in wood working for any type of stressed joints. Generally it is used for smaller tasks like replacing splintered pieces in a hurry or hold two pieces together quickly which can easily be knocked apart. The other thing that they can be used for is for drop filling with a lacquer or shellac finish (I just learned about this a couple weeks ago). The thin CA glues move in a capillary action in that they will find a way into the smallest of gaps and often times get where you don't want it (but will always get where you do want it too), this is often refereed to as "wicking in" the glue. It has also been used for closing cuts in the skin when a needle and thread is not available. Places on the guitar where CA is found is mostly in inlay work and more builders are using it for attaching bindings and purflings to the body (a non-stressed joint). Some people use CA for pore filling as well. Clean up is usually done with a scraper or sandpaper. Cure time is pretty much instant to 1-2 mins depending on CA viscosity.

I don't necessarily agree with Ken when he says there should be no to almost no squeeze out when it comes to glue. I also don't think you need excessive squeeze out either. There is a balance and you want some amount of squeeze out all around to tell you that all the surfaces have been covered. Clamp spacing and pressure is just as important as glue coverage. To few clamps spread out to far and your parts may not come together fully. To few clamps spread out to far with over clamping may cause gaps as well. To many clamps over clamped (pressure) can push to much glue out of the joint and starve the joint, thus causing the joint to fail when stressed.

I do agree with Ken that one needs to learn the proper amount of glue to use, but I also think it's just as important to know how to properly prepare surfaces for gluing and how many clamps to use, where to place them and how much clamping pressure you need. This is usually learned from one of two ways. Trial and error (or success) or under the watchful eye of an elder craftsman. I got to spend a couple years as a joe boy in a custom cabinet shop years ago. I did more clamping than I care to remember (more sanding too) but one thing I learned was to make sure the surfaces were prepared right, how much glue to use, where to put my clamps and how hard to clamp it all down. I made several mistakes that required correcting (they say that's how you get to be a good woodworker, by correcting your mistakes) and for allot of those old guys, that must have been fun to watch cause they gave me the gears every chance they could, but they were also willing to praise you when you did something well (not just right but well). They expected everything to be right.

This is what I know about glue, I'm sure there's more that I've missed.
Author:  WudWerkr [ Mon Dec 27, 2010 11:04 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
Thanks guys this is great information , exactly what I was looking for [:Y:]

Mike you mentioned that a part just fell off , what was cause ? lack of experience with the glue ? If yes , how does a newbie best avoid that situation?

Thanks Rod for the refrence to an earlier post [:Y:]
Author:  Mike Lindstrom [ Tue Dec 28, 2010 3:47 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
WudWerkr wrote:
Thanks guys this is great information , exactly what I was looking for [:Y:]

Mike you mentioned that a part just fell off , what was cause ? lack of experience with the glue ? If yes , how does a newbie best avoid that situation?

Thanks Rod for the refrence to an earlier post [:Y:]


I should say that parts don't seem to fall off anymore, but I'm not sure why. That's not very comforting now that I think about it... The parts that fell off were all side braces that a friend of mine "helped" with on one particular day. I assume he (or I) was too slow in getting them in place and the glue had cooled too much, or we moved them a little bit clamping up. but the cool thing was I just heated them up a bit, brushed on fresh glue and slapped them back in place. No sanding or scraping. Still holding strong.

Mike
Author:  nyazzip [ Tue Nov 08, 2011 1:37 am ]
Post subject:  Re: Glues and their diffrences ! Explain please !
....tonight was my first ever experience with hide glue. it was the granulated type, a sample someone gave me. i wanted to glue on a fingerboard on a cigar box uke.
first thing i did was add about 2:1 H2O and let it sit. it turned into a firm grainy mass pretty quick. added a bit more water. sat about an hour, room temp. then i heated it in a saucepan, double boiler style. unfortunately it got up to probably 170-180F. anyway i went ahead with the glue job, after tacking the fretboard with 2 brads thru the fret slots....i didn't heat up the parts or anything; ambient temp was around 70F. after setting a few clamps i pulled the brads to make room for more clamps, added a few more, and walked away.
about 45 mins later, i went to get a few photos, and i noticed to my horror thet the fretboard had shifted a couple mm off center! must have happened when i pulled the tacks i guess.
i easily(too easily it seemed) pried the rosewood fretboard off of the mahogany neck with a paint scraper. the glue was still a rubbery gel. i noticed the glue that had been exposed to air was a hard glossy shellac appearance, however.
tomorrow i try again.
just made me wonder, why it was so easy to pry off after 45 mins...? next time i will heat the parts a bit with a hair dryer or iron i guess. also i will use a bit more water, maybe let the glue settle and pour off the water from the surface......not so sure.
one thing that is sure, that stuff stinks! i guess you get used to the carcass/butcher/hide tanning smell eventually [xx(]
Author:  DennisK [ Fri Nov 11, 2011 5:33 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
You've got some guts trying a fingerboard for your first HHG experience! That's the toughest joint I use it on. Such a large area, it's hard to keep it warm enough not to gel before you get the clamps on, and keep from sliding while clamping (as you've discovered!). Easier on an uke than a guitar, though. I do water down the glue more than I do for bracing, so I can spread it thin so it squeezes out enough without sliding all over the place and making a big sticky mess. But don't overdo the water either. And spreading it thin makes it cool (and dry, if you give it another shot of hair dryer after spreading the glue) very quickly, so it's really tough to get the clamps on fast enough.

Another thing that could have caused your easy peeling is if the fingerboard expanded from absorbing water from the glue, and bowed, peeling the edges of the joint apart. For that, you can brush water on the outer surface of the fingerboard to equalize the expansion, or you can scrape the center of the fingerboard glue surface to make it just a tiny bit concave (just a couple thousandths or so, to where it can be squeezed flat by clamping pressure to get the glue thin, but remain flat as the moisture soaks into it).

But the nice thing about hide... you can try again :) Just clean off the old glue with warm water, and brush on some fresh. Good luck on the next attempt!
Author:  nyazzip [ Sat Nov 12, 2011 1:53 am ]
Post subject:  Re: Glues and their diffrences ! Explain please !
Quote:
You've got some guts trying a fingerboard for your first HHG experience! That's the toughest joint I use it on.


...no, not "guts", just ignorance! you can see my project titled "cigar box thingy". i wanted to use hide glue for the FB as thats by far going to be the most valuable(work-wise) component on this experimental piece. i never did affix the FB; not yet. i have to say i don't really trust my hide glue techniques, as i tested another joint and popped it apart the next morning, with zero wood tearing
Author:  cyborgcnc [ Thu Dec 29, 2011 11:05 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
Not sure if anyone here had seen this article, but I think it has a TON of great information on all the types of glues...they also go about determining the strength of each glue, in a rather "scientific" method...

You can get a copy from their website here:

http://www.finewoodworking.com/Material ... x?id=28897

A GREAT read!
Author:  Tai Fu [ Sun Feb 05, 2012 11:52 pm ]
Post subject:  Re: Glues and their diffrences ! Explain please !
I feel the reason why CA glue isn't used for guitar building as a structural joint is because of its quick cure time...

I used it to close a previously glued neck crack in the past because it had old glue inside which nothing else will stick to. The joint was reinforced with a spline though.
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