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hello
someone gave me a sample of granulated hide glue this summer, i tried it with seemingly good results in the fall. i'm about to glue up a laminate strip neck with it today, and i'd like to verify how you guys prepare it. this time i:
put some in a stainless steel cup, and added room temperature water. i was going to let it soak a few hours, then start heating it in a double boiler to around 150F.
is this good enough? do i need to say any magic spells or anything?
i intend to heat the pieces in the oven at around 150 so they are thoroughly warmed up
my initial attempt this fall, i didn't even warm up the wood, and it seemed to work well, but it was smaller pieces. this neck blank is 60cm long: 2 pieces of mahogany and an ebony center strip.
...please don't tell me "not to use hide glue" for this; i know its not necessary or recommended, but i want to try this all with hide glue, the old way! also, i was encouraged by how stiff and light the hide glue seemed a month after i used it in my initial experiments

http://www.frets.com/FRETSPages/Luthier ... eglue.html

Sounds like you have the idea. Check out the link above for everything hide glue.

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http://www.booneguitars.com
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I´ve only used HHG for a short while, and i do it similar to what you say - the main difference being that i don´t use steel pot. Here´s how i do it, FWIW:
Put glue in a glass cup; add cold water (with my glue - 225 bloomgrams, IIRC - i weight +- the double of water and it seems to work, resulting in the consistence of olive oil when hot); wait a couple of hours; heat until it gets to the desired thickness; slightly plane the joints afresh; slightly heat the wood with a spirit lamp(or whatever); spread the glue with a basswood glue brush (like this: http://www.mehr-als-werkzeug.de/product ... -Brush.htm); hold for a while; clamp; slightly re-heat and adjust clamping pressure; remove most squeeze out with damp cloth; wait 1-2 hours and chisel out the remaining glue squeeze-out (it should by now be gelled).

Maybe i could improve some points (a thermometer would be a good idea), but it seems to be working so far. Good luck.

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member of the guild of professional dilettantes

Oh, and it helps if your shop is heated and at ~45% RH. Never used it in mahogany, though. Maybe it would be a good idea to use a dilute 1st coat of glue and wait some time before re-applying.

More info:
viewtopic.php?f=10101&t=19293&hilit=+hide+glue
viewtopic.php?f=10101&t=28411&hilit=hide+glue

again, good luck!

cheers,
miguel.

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member of the guild of professional dilettantes

You will need to be fast to glue up neck laminations, and probably not gain anything from using hide glue. I use it for bracing backs and sides and dovetail necks and bridges. For other tasks Fish glue is just as good and much more forgiving as to time before clamp up must be completed.

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

hmmm thanks for all the input. i got impatient and went ahead. i think my glue was a little watery, especially for this application. mainly, i had clamping problems. also to complicate things, my center strip is 2 pieces, in order to get enough length, and "scarf" jointed up at a 30 degree angle or so. i guess i should have tried to join them first but i didn't
anyway, my clamps are inadequate, i used those "squeeze/friction" type bar clamps....not sure if the 150 degree oven or wet hide glue did something, but it seemed like there was some warping going on that wasn't there last night, so it took a lot of power to close the gap.
none of this would have been a major issue with slower setting glue.
luckily my materials cost next to nothing! i used mahogany strip from a Menards home improvement store. it looks/sounds good though! about 7$ for two necks worth!
i will unclamp tonite and assess the situation, but my expectations are low

Your best bet is to glue up some spare pieces of wood and test out the procedure. I'm no expert, but I love using hide glue in guitars. What you're experiencing is reticence because of the potential unknowns. Pretesting on scrap helps show you that it's really simple.

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)

i know, i'm horrible at doing mock ups/testing....i am impatient and just want to dive in! but as i said the wood is very inexpensive(except for the 30 year old ebony, which i assume can be salvaged), so, this is in effect a "test". heck, prettymuch everything i have ever done is a "test", come to think of it. i've never done anything twice, exactly....

I see you already tried this. . . I was about to say that I was not too sure that baking the parts was a good idea. You would be driving down the moisture content then immediately putting water on one side of each piece. I think that is the result of your warping during glue-up. I'm no expert, but I would recommend you do it this way:
First glue up the ebony scarf so you are only dealing with 1 piece there. Even better if you can glue it up then thickness it as one piece. I would also set up a clamping system such that you can do this in stages. This will likely include some sort of indexing (dowels) in the waste areas. Glue the center strip to one side with cauls to ensure it stays straight (the water in the glue will try to warp the pieces) make sure to use wax paper or other treatment to avoid gluing the neck to the cauls. Warm them before hand with a heat gun (gently), hair dryer or lamp. By only doing one joint at a time, you don't have to get it too hot nor will you have to rush as much. Once the first side has gelled, warm up the other piece, unclamp apply glue and clamp the whole thing back together. Leave the neck blank clamped in the rigid straight cauls for at least 24 hours. Hopefully, the added moisture on both sides of the center lam will be about equal and the cauls will hold it true while it dries.

I am far from an expert, so you should probably wait for someone to come along and correct me.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Putting the wood in the oven probably wasn't the best of ideas. If you are going to warm the wood it has to be gentle heat, just enough so that the glue doesn't gel on contact. In your glue up scenario I would have a few heat lamps over the bench, it helps prevent the glue from gelling even after you have applied it to the surface. Even warming the bench surface helps. I once glued 24 short strips of veneer (for rosettes) using this method, that's a pretty long glue up in anyone's book. Of course you need everything to be efficient, the size of brush, clamps all at the ready etc.
You should have all the pieces of wood laid out next to each other, applying the glue to all surfaces in one go - almost like slopping on wallpaper paste. It becomes fast, efficient and easy once you have everything organised.

yeah i had mixed feelings on the oven thing. but it was only 150F....and, it is a gas oven- H2O is a byproduct of natural gas combustion, so i figured, its already dry here with this cold snap(33%RH), maybe the oven might even add some moisture.
bottom line is, i don't have any heat lamps, and the hairdryer, on such long pieces, i figured wouldn't work great, not to mention blowing dust everywhere!
next time: thicker glue mix; infra red lamp; more big C clamps; no oven; and do it in 2 stages. as it turns out i prepped enough wood for 2 necks, except the other will have a rosewood stripe instead of ebony....
i unclamped it, and sure enough one end was separating, so i stuck that end in pot of hot water and reglued/reclamped. we'll see tomorrow....
how much time should elapse before unclamping, anywho? i generally go 8 or more hours, but sometimes i get excited

The nicest thing about HHG is that when you mess up a glue up, you can just take it apart and start over. I don't think you want thicker glue, you want it to flow nicely. Long glueops are trickier but the parts don't have to be 150*, warming the parts just gives you a bit more time before it starts to gel. The best thing for you to do would be to spend an evening glueing up some scraps and getting comfortable with the working properties. You have to be efficient, but no need to panic. You have to get used to it so you can be calm but fast. . .

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

For well fitted parts, the glue can be thinner (say 2 to 1 for ~200 strength) For things like dentellones or binding, it should be slightly thicker (1.8 or 9). Usually it gets noticeably thicker after a couple hours under heat. A thick glue makes a very good adhesion too and is less prone to starving but you can easily get thick glue lines which can look bad especially on a soundboard. The thin glue is more prone to starving so you must not overclamp it too fast. Thin glue tests I made seem to fail at the joint easier than thick glue tests which have more wood breakage.

I did a couple 3 piece necks with hide, in 2 sessions. First I glue 2 pieces, let it dry for 3 days, straighten the side again and glue the second. I used the go-bar deck as it is the fastest clamping I can come up with. Heat the parts with a hair dryer for a minute, paint a generous layer on both sides, press it gently (no need to get excited or rush it) wiggle it a bit back and forth and start clamping.

You also need to wait a few days after gluing the headplate. It gets a noticeable crown and if you level it right away, it will turn concave later.

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Build log

if the oven is really only 150, that's probably not an issue if you're leaving the wood in only long enough to warm it up, but I think I'd heat it to 150 - then turn it off to cool before putting the parts in. The parts don't need to be hot, just warm enough not to shock the glue into gelling upon application.

Lots of good suggestions here, and the only thing I haven't seen added is that hide glue weakens if its heated over 145 degrees fahrenheit (I'm sure someone can provide the logarithmic scale, mapping every degree over 145 versus acceleration of the impact on the glue, etc.... - but I try to make sure my hide glue doesn't go over 145. The cheapy digital thermometers from Target, etc. are perfect for this.

+1 on tight fits, warm parts being glued, moving quickly. I love hide glue, and the fact that it's non-toxic is an added plus for me.

I don't think the oven was a good idea......but I'm not sure. I heat my bridges on hot plate because it takes a little time to get everything positioned right and clamped.

Reguarding procedure, the first thing, a warm shop. Hot hide glue gels at ~90F. With 140ish F glue in a 75 to 80 degree shop you've got ~90 seconds. Glue thats thinner (more water) cools quicker. I've read where people said they added water for more open time, but the opposite is true. 90 seconds is a LONG time. Get a timer and practice. Spreading the glue is what takes the most time, and that's hard to practice. Pre heating helps alot with big pieces. I use a heat gun for closing the box. I suppose a hair drier would work.

From my experience mix ratio (water to glue) isn't that critical. Find a consistancy that works for you. Again, thicker, at least to a point holds heat longer, but may require more clamping pressure to get a thin joint. I used to weigh mine, but lately I just put some glue in a container, and cover the granules with water. If it gels before it's clamped no amount of pressure is going to make a strong joint. If you have a joint that doesn't get clamped tight before the glue gels you can heat it, and clamp it. I do this with kerfed linings all the time. Instead of preheating I just apply glue, clamp, then heat any section that gelled too soon.

I've been told that higher gram strengths gel faster/lower slower, but I don't even know what gram strength I use. I've got a couple 5 gallon buckets of dry glue that's been in my family for several generations.

Lastly, you said you didn't want to hear "don't use hide glue for neck laminations", but perhaps you (and others) don't know the reason. IMHO neck laminations should be glued with something that doesn't creep, which is a reason to use HHG, but I believe neck laminations also should be glued with something that doesn't release with heat. If you ever need to remove the fingerboard, or remove a glued in neck joint you'll be risking loosening the laminations. I've used polyurethane glue for neck lams, but lately I've been using urea formaldhyde glue.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Try fish glue. Very very heat resistant, and ridiculously easy to use.

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Build log

I'm with Woody on the neck lam glue. I use PU for the lam because I don't want it to ever come apart. I like to use HHG for the Fretboard for easy removal should it be needed. I know many people avoid using waterbased glues for the Fretboard because it can bow the neck as it loses moisture. I have no real time schedule and leave it clamped for days to my marble slab and work on something else. I have not noticed any issues with it staying straight.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

that is a very good point about NOT using hide glue, in the case of future fretboard removal. i did not think of that !

didn't think about that either, but...if this ever becomes anything, it will become a nylon string neck, with a "spanish heel". i dunno if i would ever be able to pull off a dovetail in a million years