Dumb Adhesives questions

sebastiaan56 · Post by **sebastiaan56** » Thu Nov 22, 2007 8:21 am

Hi everyone,

I thought Id lower the tone of the list with a couple of dumb questions about adhesives. Googling has not yet brought me the answers.

Ive used Titebond 2 almost exclusively. I read on MIMF that it can creep. Now, Ive been called that a few times but never found out what it means in a Luthiers context. Ive also heard the same for white PVA's so there must be a reason for the alphitic's.

Im also fond of epoxy, as a matter of fact the classical Im finishing is probably half epoxy by now. Is it suitable for joints that need some movement? I have heard that it is often stronger that the substrate being glued but nothing about rigidity. Would you use to put a soundboard together?

Does anyone use hide glue? What is the open time? What are the advantages apart from being able to heat and seperate? or make a fabulous gravy stock?

Ive used CA to tack pieces into place but am not game on structural components, once again it strikes me as being too brittle for an instrument designed to flex.

I expect that is horses for courses but would like to understand more. Thanks for your comments,

Sebastiaan

Bob Connor · Post by **Bob Connor** » Thu Nov 22, 2007 8:56 am

Creep means that the glue does not set absolutely hard and over time may move if under tension.

Think of a bridge. The tension of the strings will attempt to pull the bridge toward the fingerboard over time and the bridge will creep.

Titebond Original is used extensively as is LMI White glue which supposedly sets harder then Titebond. (anecdotal evidence - I've never used it myself.)

Open time for HHG is about 30 seconds.

I think there is enough evidence to assume that HHG is superior tonally due to it's hardness when set.

Having said that Wayne Henderson (Clapton's Guitar) uses Titebond on everything as do many other factory manufacturers.

Contrary to popular belief Titebond will come apart at a lower temp than HHG.

We use either Titebond or HHG. The current batch that we are making will have Titebond gluing the backs, sides, linings together and HHG for anything to do with the top and bridge.

Epoxy for glueing fingerboards and CA for rosettes, some bindings and purflings.

I use Titebond III for gluieng side purflings to bindings so I can whack 'em in the bender without them falling apart.

There has been a lot of discussion on the OLF about Fish Glue which has the same properties as HHG but a longer open time. Haven't tried it but it may be the answer to overcoming the short open time of HHG.

If you are interested in HHG 192 gram high clarity is the stuff you want.

I get it from Tools for Working With Wood in the States.

http://www.toolsforworkingwood.com/Merc ... egory_Code

There is a huge amount of info about HHG on Frank Ford's Frets.com site.

Bob

graham mcdonald · Post by **graham mcdonald** » Thu Nov 22, 2007 9:38 am

Bob has summarized it pretty well. Hide glue is wonderful, but it involves dissolving it and heating it up and you don't have much time to get the gluing done before it sets. Good in a production environment where gluing is going on all the time, rather more annoying in a home workshop where you might do two glue jobs a day.

Original Titebond or the LMI white glue, which I have been using recently and it seems fine. The Titebond can at least be bought locally from Carbatec and Gerard Gilet (others?) There are a number of other yellow aliphatic glues on the market, but they really needs some testing before use on the critical bits of instrument building (like gluing bridges!)

I have gone over to gluing fingerboards with epoxy, mainly because of a couple of back bows that developed after gluing with Titebond. Either the RH was too high or the moisture in the glue causing uneven swelling. No problems using epoxy, though I am careful to now glue fingerboards at low RH. Don't use hardware store epoxy(ie Araldite). Go to a model aeroplane shop and get one of their 30 minute epoxys. I have some NFS (or a three letter name like that) at the moment. Z-poxy is good as well and of course the West Systems. Z-Poxy finishing resin is also excellent as grainfiller/sealer

cheers

graham

Arnt · Post by **Arnt** » Thu Nov 22, 2007 11:36 am

I'm using Lee Valley fish glue for almost everything now. As has been said, it acts a lot like hide glue, but with longer open time. It also has a longer cure time (the bottle says 12 hours), so it ties up the clamps and go bars, just plan ahead! It is also more difficult to clean up, but with a little persistence you get it off with water.

It shares another important characteristic with hide glue; it shrinks as it dries, thereby drawing the surfaces of the joint closer together. Like hide glue, it can be used to create a rubbed joint; no clamps are used to hold the parts, and the glue itself will draw them together as it dries. If you have nicely prepared, fresh surfaces this means the glue line will be extremely thin and solid.

Well mating surfaces are important as the glue itself is not very strong; it sticks to surfaces by electrochemical attraction. The hardening of the glue occurs entirely by evaporation. Epoxy glue has higher cohesive strength, and will make a strong joint even if the surfaces don't match well, meaning it also fills gaps well which can be useful. It is however not as heat resistant as the animal glues.

Fish glue is sometimes reported to have low moisture resistance. I have done some tests, and have not found it to be any more so than hide glue. I believe the humidity conditions that would hurt the glue would hurt the wood in the instrument a lot more, and you would have other dire problems besides the glue failing.

Dennis Leahy · Post by **Dennis Leahy** » Thu Nov 22, 2007 4:24 pm

*anecdotal* One of the luthiers who posts on the Luthierforum, Michael Boyle, says he has been using Knox unflavored gelatin as a clear, non-smelly, cheap, and readily available "hide glue" for 15 years.

*double anecdotal* Someone else (I can't find the reference) said that Martin Guitars uses gelatin (hide glue) plus wheat paste to fill tiny tear-outs in spruce tops. Supposedly, it ends up the right color to hide the flaw.

Dennis

Allen · Post by **Allen** » Thu Nov 22, 2007 6:04 pm

Australian Luthier Supples and Gillet Guitars also sell hide glue. I get mine from Australian Luthier Supples. I've also seen a few Autralian ebay sellers offering it.

After switching to it for plate joining, brace and bridge work I wouldn't use anything else. Very easy to use, especially here in the tropics with our constant 30+ degrees. I would guess that I'm closer to 45 second open time up here.

I use Titebond Original for most other glue operations and CA for somethings where it is just the best choice.

Dave White · Post by **Dave White** » Thu Nov 22, 2007 7:34 pm

Sebastian,

I use hot hide glue (hhg) on most things and fish glue where I need a longer time to set up the joints. It takes a bit of a learning curve to get used to hide glue but when you do it is wonderful to work with - it tacks to the wood beautifuly rather than the "alphatic skating experience" and clean up is a breeze - just wait for the squeeze out to gel and peel it off. You can mix batches as you go or use an ice-cube tray to make hide glue cubes and store them in the freezer, using a cube as you need to. You don't need an expensive glue pot either - I use a Mothercare baby-bottle warmer that works great.

I used to think it a myth that you got a better sound when you used hhg thinking that a lot of builders changed to it at a particular time in their building experience and that it was their skill level. But I heard a step improvement change in sound with the first guitar I used hhg for the top braces and bridge. HHG and fish glue are also pretty easy to take joints apart - you need heat and to work in some moisture.

LMI white glue is a love hate thing in my experience and reading other builders views. People either swear by it or at it. I had some bad experiences with it (probably my technique at fault) and won't use it anymore. It could be that it froze in shipment to the UK - not good for these glues.

matthew · Post by **matthew** » Thu Nov 22, 2007 11:16 pm

I prefer hide glue for all glueing (except for graphite inserts) and I have a great little system.

I grind the "pearl" hide glue pellets in a spice grinder, sieve through a tea strainer and have a small jar of this on hand.

I have an upturned clothes iron in a wooden mount, with a piece of fibro covering the iron sole to distribute the heat a bit.

When I want to glue something (even small) I put a teaspoon of dry glue into a small vegemite jar, cover with water from a squirty bottle and flick on the iron. About 5 minutes later the glue is ready to use. add a squirt if too thick. No mess, no water bath, and with a lid on it the glue can last several days in a cold gel state and reheated without a problem.

Tricks are:

- warm the glue surfaces with a hairdrier or heat gun to increase open time
- use clamping "stops" to stop the piece skating
- prime both surfaces with glue before putting together
- surfaces should fit REALLY close, no need to score surfaces
- use a spatula dipped in hot water to resoften and remelt glue.

the only thing I don't like about hide glue is cleaning the brushes, but I buy a bunch from the $2 shop and just chuck them out after a while.

Hesh1956 · Post by **Hesh1956** » Fri Nov 23, 2007 12:55 am

The reasons why many builders move over to HHG for some things in time is that it is superior tonally but slightly more difficult to use.

The best way to see and test this for your self is to glue two pieces of scrap, one with HHG and the other with Titebond. Then plane the scrap off and when you get to the glue joint chisel the glue joint off. If both glues are properly cured you will find HHG much harder and glass like then Titebond. This hardness transmits vibration better.

Although original, plain Jane Titebond is a wonderful glue in really all respects HHG is superior in places where you wish for vibration to transfer from one piece of wood to another. For me this includes all braces, bridge plate, bridges on the top and all back braces.

Remember too that HHG is not gap filling nor should it be. This means that your joints need to be perfect and clean prior to using HHG.

Epoxy, is really a very different animal and although great for fret boards it is to soft and to thick IMHO for braces unless you are working with a wood that does not glue well with other glues, cocobolo for example.

There is a learning curve with HHG and you do need to do dry runs and be sure that you can have all your clamps in place in 15-30 seconds max. You want to heat it to 145 degrees or slightly less, never more.

Clean-up with HHG is superior to any other glue IMHO. Just by waiting 5-8 minutes the HHG squeeze out will come cleanly off, in one piece, with a squeegee action and say an engineers scale or a piece of binding.

Like Dave when I made the switch to HHG I heard a difference as well.

Fish glue I am just starting to use in selected places. It too dries to the hardness not unlike HHG and I am impressed.

CA, IMHO, has no place on a guitar unless for inlay work or perhaps to drop fill a nitro ding.

Allen · Post by **Allen** » Fri Nov 23, 2007 6:36 am

Can people comment on why the consensus seems to be for epoxy on the fret board and perhaps laminations in the neck? I've only used Titebond for gluing down the fret board and laminations.

Bob Connor · Post by **Bob Connor** » Fri Nov 23, 2007 6:47 am

Here's a snippet from the Titebond website Allen

Water based wood glues such as Titebond Original or Titebond II build strength in a joint as they lose moisture into the surrounding wood. This moisture causes the wood on both sides of the bondline to swell slightly.

I've used Titebond for glueing fingerboards and every time I've had problems with fret buzz around frets 5-7.

Since switching to epoxy this has become a non-issue.

Still use Titebond for glueing up neck laminations though I'm considering epoxy for this too.

Bob

Allen · Post by **Allen** » Fri Nov 23, 2007 6:59 am

I understand that the moisture is lost into the surrounding wood initially, but doesn't it continue to be equalized over time with the RH of the instruments environment?

I've not experienced this before, (fret buzz in the 5-7 position) but I install frets before the board is glued down, then level after it has been glued and cured for about a week. Sometimes more depending on my schedule. Perhaps this is why I haven't come across this?

Could be that it's just so humid up here that I don't see the same problems that others do in a drier climate. Just a thought anyway.

I'll be gluing on a fret board in the next week. I think I'll give the epoxy a go and see if I notice any difference.

Bob Connor · Post by **Bob Connor** » Fri Nov 23, 2007 7:04 am

We install the frets using a press before the fingerboard goes on too Allen.

Since using epoxy we don't have to level the frets. They are pretty well spot on.

We maybe have to touch up one or two frets but that's about it.

Bob

Allen · Post by **Allen** » Fri Nov 23, 2007 7:06 am

The press makes that kind of difference? I'm gonna have to put one of those on the wish list.

Bob Connor · Post by **Bob Connor** » Fri Nov 23, 2007 7:21 am

Hi Allen

Do an Ebay search for Arbor Press.

There's a few available for about $80 out of Melbourne.

We got the Fret Press Caul from Stewmac.

There is virtually no back bend in the fretboard when using the press.

I'd never go back to bashing the bloody things in with a hammer.

We looked at buying the Stewmac setup but as they only airfreight the cost doubled.

Those arbor presses on Ebay are identical to the Stewmac ones.

You'll need to do some drilling and tap and die a screw to fit the caul.

Well worth the effort.

Cheers

Bob

Dave White · Post by **Dave White** » Fri Nov 23, 2007 7:31 am

Allen/Bob,

I've used Titebond original to glue almost all of the fretboards I've done and not had backbow issues - well I may have but as I fret when the fretboard is on the neck, I level and radius the fretboard when it's glued to the neck.

On my Weissenborns I used hot hide glue to glue the fretboards to the body reasoning that as they are on hollow necks it's transmitting some sound and if I use hhg for a bridge . . . On my latest build I used fish glue to glue on the fretboard.

I just hate epoxy and it's messiness/cleanup - I use it for securing my cf flying buttress braces but hate the operation of using it. Z-poxy as a grain filler I love using though.

Graham W · Post by **Graham W** » Fri Nov 23, 2007 7:43 am

Hi Sebastiaan

I use aliphatic for just about everything, including fingerboards. I find it great to use and I haven't experienced any noticable problems with creeping or fret buzzing. In my experience aliphatic is strong enough for most glue joins on a guitar and it has one BIG advantage over epoxy i.e. the join can be taken apart relatively easily. I reserve the use of epoxy only for joins that I know are never going to need taking apart e.g. laminating a neck or body, stacking a heal etc.

Who knows when a join may need to be dissassembled to facilitate a repair? eg broken truss rod requiring the fingerboard to be removed. Aliphatic is not a lot of fun to take apart, but I'm guessing it's easier than epoxy. Thankfully, to date, I haven't actually had to do this sort of thing, but strange things and accidents do happen, especially on professional instruments that are travelled regularly - occasionally joins need to be opened and repairs made.

Is there any advantage in using adhesives that are stronger than the actual stresses on a guitar call for? Ever tried to remove a bridge that's been glued with epoxy?

Not a very technical letter, I know, but hopefully food for thought.

Cheers

Graham

Paul B · Post by **Paul B** » Fri Nov 23, 2007 8:26 am

I'll second Bobs remarks on the fret press. I've done three with mine and they've not needed any more work after being pressed in. As long as the fret board is prepared nicely, I've been able to press the frets in, bevel the ends, and forget about them.

Ron Wisdom · Post by **Ron Wisdom** » Fri Nov 23, 2007 10:19 am

I use titebond original for nearly everything, including FB and have had no problems at all. I like it.

Ron

Hesh1956 · Post by **Hesh1956** » Fri Nov 23, 2007 10:39 am

Most of the guitars that I have built had Titebond as the fret board glue and back bow was an occasional problem. But I too level the fret board after it is on the neck, sometimes.

The reason that water based glues, HHG included can result in back bow is not only the swelling but the glue setting while the neck is in a back bowed, because of the swelling, state.

I did some test with pressing frets and hammering frets and my results where clear - I had half the fret board back bow pressing as I did when hammering. Sometimes I press the frets in the fret board off the neck and some times I press most of them, that I can get to, when the fret board is on the neck. It seems that I am building with 3 different styles these days and this sucks.......

Any way I have an idea for pressing frets in the fret board while the fret board is off the neck. I plan to test this as soon as I can make the jig that I need.

The idea is to eliminate the back bow entirely from pressed frets when the fret board has not been installed in the neck. The jig would be a supporting surface, probably hard Maple, under the fret board in the Arbor Press that is radiused very slightly to bow in - say a concave 30' radius. A small amount of CA would be added to each fret - yep CA. Since the fret will be pushed into the slots when the slots are ever so slightly closed by the radiused caul underneath back bow would be eliminated. What radius will work best will be a trial and error thing.

I have gone to epoxy for gluing the fret board to the neck for the reasons stated above. If you can eliminate neck back bow AND the back bow of the fret board over the body you save a whole lot of unnecessary steps.

Lillian · Post by **Lillian** » Fri Nov 23, 2007 11:51 am

I remember a thread over at MIMF about dealing with fret boards back bowing after frets were installed. The thought was that the barbs were not setting into the sides of the slot, so they were forcing the board to back bow. One of the remedies was to press the frets in with the fretboard off of the neck. Spacers were put under the board at each end and then the middle was clamped down pulling the fretboard down, forcing the barbs to dig into the slot sides.

Tom Morici · Post by **Tom Morici** » Fri Nov 23, 2007 8:05 pm

Since I started with HHG since my first build 38 yrs ago, no dispute from me on its merits. As others have said here, you have to follow the rules with HHG, but once you get it is easy.Titebond works well, but cure time to reach full hardness can take weeks. (or longer) Sure for most woodworking 12 hrs. is plenty. Titebond is used by many and works well for them. For furniture it is the only yellow glue I use. Titebond II sucks!
I use 2-part epoxy for CF, makes a good bond, but for wood to wood joints, West Systems resin thickend with wood flour, or other fillers
(cabasil, microballoons) is a permanent waterproof joint.

I will admit I am biased against epoxy for the fretboard, keep in mind I have repaired and restored vintage instruments for over 30yrs. I had one
old Martin that came in for a neck set that someone glued the neck in with epoxy. I had to pull the fretboard off to get at the joint, it was nightmare even then to get it apart. I am still mad at that guy!

Now that I have that out of the way, and I quit doing repairs

a lot do use epoxy for the fret board. The moisture logic makes sence, but it has never been a problem for me. Too each his own.

Fret presses work great for straight radius fretboards but since almost every thing I build I use a compound radius fretboard mine sits ideal most of the time.

IMHO
Tom

matthew · Post by **matthew** » Fri Nov 23, 2007 9:00 pm

I might be missing something but I find HHG pretty easy to use. I just heat it till it runs like thin cream, and it's ready. if its too thick I add a bit of water. I don't use a thermometer.

Kim · Post by **Kim** » Fri Nov 23, 2007 10:19 pm

Mathew,

Apparently once HHG is exposed to temps above 150 deg F, the proteins begin to break down which weakens the bond strength.

Cheers

Kim

matthew · Post by **matthew** » Fri Nov 23, 2007 11:27 pm

True, but I don't think my glue gets anywhere near that. I did use a thermometer once to check. It gets hot enough to run, then that's enough heat.

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