Official Luthiers Forum!

Hello,

I'm learning some good lessons about using hide glue. David Farmer said once that my "titebond eyes" are going to think I'm using too much hide glue and that is certainly true. I do think though that I am still overdoing it because I'm getting so much squeeze out. I recently put a bridge on a uke and the squeeze out got underneath the tape dam that was framing in the bridge. Unfortunately it distorted the shellac finish a little and no matter how much polishing or additional shellac I put on in the area it still looked dull compared to the areas around it. That got me to thinking that maybe the procedure I'm following needs some tweaks. I'm using the same gluepot that SM sells which keeps it a 145 (I think ).

Some guidelines I'm following:
1) Hide glue is mixed 2:1 per Frank's recommendation here: http://www.frets.com/FretsPages/Luthier ... eglue.html The consistency is about that of warm maple syrup. It flows pretty fast and freely.

2) Warm the part to be glued under a heat lamp for about 2-3 mins before starting the glue up.

3) Apply glue from a squeeze bottle and immediately place into clamping position.

4) Hold for about 20 seconds or until glue starts to grab and then clamp up.

5) In the case of the bridge, hook up the vacuum clamp and run it for 10 mins, remove and cleanup squeezeout, then run for another 30. In the case of other items clamp in the go-bar deck and clean squeezeout as soon as possible.

Some things I'm thinking of trying:
1) Maybe the glue is too thin? I'll be using the higher gram strength for guitar bridges but for this uke I used 192. Do you folks use a thicker consistency than 2:1?

2) Maybe wait just a few seconds after putting the glue on before placing the piece? Just to let the glue set up very slightly?

3) Maybe only heat the part in advance for certain operations where open time is critical? I'm think operations like putting on a top or back. Maybe I don't need to heat for bracing, block or bridge glue-up? The vacuum clamp is super fast to get going so maybe I don't need the same time as those who use clamps?

Any feedback on the procedure I'm following or the steps I'm thinking of tweaking is appreciated.

Also, regarding cleanup - I'm basically wiping with a shop towel paper towel that was dipped in the water from the glue pot, then switching to q-tips dipped in the glue pot. Should I wait longer and let it setup more? Should I worry about not getting any water, at all, near the joint? Any tips there are appreciated too.

Thanks!
Brad

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Brad, I still haven’t managed to deal with hide glue squeeze out on a shellac finish to my complete satisfaction yet, so you’re not alone.

A couple of notes. John Hall likes to say, wait until the glue “boogerizes.” Sadly, I know exactly what he means

At which point, you can pick it off. I use sharp bamboo skewers around the bridge when I do that, but I invariably scratch a little bit of stuff too.

I assume practice makes perfect.

Sadly, I’m a long way from perfect.

Steve

I believe that the goal at glue-up is to thin the glue line before the hide begins to gel and tack, so any delay in doing so (such as to get the glue closer to tacking/gelling point) puts the joint at risk. Because hot hide has very little of the 'skater on wet ice' slipperiness of liquid Titebond, there seems to me to be very little incentive to delay closing the joint.

We do not use extra heat for most operations with 192g glue, but we also break up certain jobs into manageable pieces, such as gluing up one leg of the x-brace at a time (hint: the notch-up one goes first). We preheat bridges because we glue with 315g glue (higher gel temperature) and the bridge provides a nice reservoir of heat to remelt any glue that has gelled on the top as we get the bridge in place.

For linings and for closing the box, we keep an old Milwaukee heat gun handy to remelt any gelled glue. The lining gets a coat of glue, is held in place and clamped, then reheated to let the glue line thin.

Mr. Denvir has the heart of it on clean-up - we wait for the glue to gel, then use a knife-edged popsicle stick to cut the glue loose (vertical cut and horizontal cut...the glue should lift away), then hot, wet paper towel and a glue clean-up stick, followed by a dry paper towel to get as much excess moisture off as possible. Because the glue cleanup is done after the hide gels, it is unlikely that any glue will be washed out of a tight joint with just mechanical scrubbing on the outside surfaces, so we don't worry about losing glue from tight, well closed joints.

_________________
For the times they are a changin'

- Bob Dylan

I have tried the 2 to 1 ratio as recommended but it's always seemed too thin to me. People say it's supposed to be like honey, but yeah mine always seems to be more like hot syrup so I go thicker.

Are you leaving a tape perimeter on the Finish as you glue the bridge on, or is the hot glue going right on top of the shellac?

_________________
Pat

I leave the tape on. What I noticed with this latest Uke though is that the glue squeeze out got under the tape. Which makes me think the glue is too thin. So then it did get on the shellac while still very hot. I suspect this is why the finish distorted a bit.

If the glue is the right viscosity I’m guessing it wouldn’t have gotten under the tape?

Thanks for the feedback so far!



Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

One thing to add. After buggerization and being able to peel snot like, long stringy hocker-like peelings that are excellent to stick to your face and then say out loud, "hey Dave" I use one of my hot, wet paper towels and a blunted wooden tooth pick. Using the toothpick and wet towel piece together I work the intersection of the say bridge and top to remove glue even closer to the bridge. Then I follow-up with the toothpick and dry paper towel and then go hang the thing until I'm ready to take the clamps off.

What's for breakfast? . It looks like candy but it's snot.....

We also make that tape "well" that you may have seen at our place if we had to reglue a bridge while you were here. Removing the tape from the well at buggerization state, maybe two minutes after clamping removes 95% of the glue squeeze-out.

Pay attention to Mario P's excellent video where he glues a top on with HHG. Regardless of the short open time Mario can pull it off preheating the rim area AND exploiting the jelling properties of the HHG. He intentionally uses a squeeze bottle bead big enough so that it becomes not unlike a liquid jell cap pill that you see at the pharmacy these days for rapid release (or to simply repackage old news drugs to charge more...). The bead he lays down jells slightly but in doing so protects the liquid glue inside that remains liquid longer. When the top is clamped on this breaks open the jelling bead and releases the still liquid glue that then with clamping makes for that thin glue line and Woodie discusses and is desirable.

Brilliant!

[quote="Hesh"] buggerization and being able to peel .................quote]
Hmm, Hesh, I think you meant boOoggerization.........
And how did the cuss corrector miss that?

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Brad--

There are only a few changes to your current procedure that I would recommend experimenting with:

1. If the glue is thin enough that it goes places you don't want it to go, you can thicken up the ratio without it being a problem. I actually go a bit thicker than 2 to 1 for most tasks, and go 2 to 1 or slightly thinner when I want the glue to wick into places.

2. I would make sure that you have used something to push the tape border down everywhere so that there are no small places where the tape has lifted up, or was never pushed down enough in the first place. A small piece of wood with the edges all rounded, or a glue roller, can do a better job than a finger. Just don't dent the surface you are working on.

3. Are you just squeezing out of the bottle, and letting the glue flow where you want it to go, or are you spreading it with something? I used to use the squeeze bottle method, but I switched to using a small open container and a brush for spreading, and I feel like this gives me more control over the amount of glue and where it goes. Spreading can take a few seconds longer, but I like it better than the squeeze bottle method, which always seemed to apply more glue than I actually needed.

Thanks for the feedback, really helpful. I do use the squeeze bottle and I also wondered about that. I have a set of the silicon glue brushes from rockler, I will try those with the open container.

Appreciate it!


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Gotta get new glasses TODAY ... I thought that said ... Hyde Glue Sneeze out ........ Whhhhhooolllleee different comment !

_________________
The Shallower the depth of the stream , The Louder the Babble !
The Taking Of Offense Is the Life Course Of The Stupid One !
Wanna Leave a Better Planet for our Kids? How about Working on BETTER KIDS for our Planet !
Forgiveness is the ability to accept an apology that you will probably NEVER GET
The truth will set you free , But FIRST, it will probably Piss you Off !
Creativity is allowing yourself to make Mistakes, Art is knowing which ones to Keep !
The Saddest thing anyone can do , is push a Loyal Person to the point that they Dont Care Anymore
Never met a STRONG person who had an EASY past !
http://wiksnwudwerks.blogspot.com/
http://www.facebook.com/groups/GatewayA ... rAssembly/

For the 192 strength stuff I've been mixing it up 1.8 to 1. What I've noticed is that if I heat the parts up then it gives me more time but it also makes the parts swim around. So it kind of defeats the purpose of fast tack.

You can create thicker or thinner soloutions of hhg depending on what you are gluing ? in the vln world HHG is diluted for certain applications and thickened on others . Experiment on scrap. I have abt 3 different grades of HHG from 3 different suppliers and they all require various amts of water. Test your batches before using !!

I'll just make a few comments on how I do bridge vacuum gluing for your consideration.
-I use HHG towards the thicker end of liquid. I had a few failures early on with too thin glue, starving the joint (being pulled out by the vacuum?)
-I use a cheap 25mm paint brush to apply to both surfaces for one stroke application.
-yes to heating of surfaces
- no tape dam, I use plastic pins (2mm side dot material) through the saddle slot, CA in position in the bridge, below the slot level with a 3mm stub below trimmed with a tapered end. Just pops into position on the soundboard.
-I used to do the clamp for 10min then clean and reclamp, but now just clamp for 15min and clean
-my squeezeout tends to be foamy from the vacuum and releases fine from the finish with warm water and a wooden scraper. I guess you could clean most of it before clamping if you are in a warm room giving you time to fuss about, but I like to get the vacuum on straight away.

I think the op's problem was with the hot hide glue squeeze out on shellac. I'm curious too if anyone has been able to overcome that issue.

_________________
Pat

Never been a problem for me on shellac

With vacuum pressing, you can clean up in a minute and then repress.
Like Frank Ford, 1.9:1 by weight seems to work. Reheating 315 from the freezer gets a little thick, though.
Like Don, I use a brush. I can't fathom a bottle with hide glue. I just switched to a smaller brush. I had a small baby food bottle, glue was running low, and the brush actually cooled the glue while I was brushing. Fortunately its easy to redo!

Thanks, Aaron. I'm going to try going a little thicker with 192 (which is what I plan to use for uke bridges) and do some experiments with 315.

Indeed, the biggest concern I had was that the squeezeout seemed to distort the finish. The finish was no longer clear and adding more shellac didn't resolve it. It's totally possible it was type of shellac I used. I recently ordered some better quality shellac from shellac shack. Maybe it will not show the issue.

Thanks for all the replies.

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Shellac should be fine with 150 degree hide glue and water on it for a few minutes, but I have no experience with vacuum clamping and how that would affect the interaction. I wonder if the lower boiling point of the water under vacuum would cause it to steam and penetrate the shellac? Also possible that you had the bridge and glue hot enough to melt the surface of the shellac.

IME, there's no fixing a dulled shellac surface. Scrape back to wood in the affected area, wipe on a couple coats of shellac, level, wipe on a couple more, and micromesh to level and shine. If you're lucky, it will blend invisibly.

The initial penetration of shellac into the wood micro-structure makes a difference in how "deep" it looks in the end. If you slop generous quantity on bare wood so it has time to soak in before drying, then it will have a darker and deeper look. If you use a relatively dry cloth for the first coat, it will create a barrier without penetrating much, and keep the wood looking more light and flat. It will always have the light and flat look after steam damage, so if it was dark and deep to begin with, then you have to scrape thoroughly to get the wood texture fully opened up so the new coat will penetrate.

I use 315g hhg for bridges, the only downside is you feel like a rush of adrenaline grabbing clamps and liniing up everything.The problem for me is the small bridge footprint of ukes. I feel more secure using this for uke bridges.Shellac shack has some shellac that has wax in it.Some say it/s a nono , but it would be easier to clean the HHG off a top that had wax on it from your shellac topcoat. PS

I use 315g hhg for bridges, the only downside is you feel like a rush of adrenaline grabbing clamps and liniing up everything.The problem for me is the small bridge footprint of ukes. I feel more secure using this for uke bridges.Shellac shack has some shellac that has wax in it.Some say it/s a nono , but it would be easier to clean the HHG off a top that had wax on it from your shellac topcoat.

the directions on my HHG can for 192 call for a 1 to 1 mix
I have been using this for so long I can see when it is ready. It should be to me a light caramel color and the consistency of molasses. Too runny you have too much water if I get 2 drips then a string I am happy
I use a glue brush and apply to both surfaces and allow min 12 hr clamp time

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it