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Greetings everyone!

I have been using hide glue for a while now and want to start using it to glue the soundboard and back to the sides. Problem is I am fairly positive I cannot get all of the clamps in place before the HHG gels. Any tricks to this? Thanks!!

the way I do it when I glue the back to my classicals, is apply glue to the rims, position the back, rope the back to the guitar, and the reheat the glue with a torch (just a metal rod with rope around the tip, that was soaked in alcohol). That way the glue gets liquid again, and ensures a good glue joint.
Maybe this method can be applied to a steel string as well, though it might be more difficult, since they usually aren't built in a solera.

hope this helps.

Yeah, you'll probably need to reheat the glue after it's clamped up. I'm not sure an open alcohol flame is such a good idea though...

I used to do it by spool clamping the back on, and then removing a few at a time and squeezing glue into the gap. It sort of works, but makes a pretty weak joint because each section gets peeled back apart a bit after it's cooled, while squeezing glue into the next section.

On my most recent one I used Old Brown Glue, which is hide glue with some additives to keep it liquid at room temperature. I like it a lot, but it might be expensive to ship to Germany. But using it only for this operation, a bottle should last a long time. I split mine up into 5 smaller bottles and froze all but one. Hopefully they'll stay good for some years that way.

There are other liquid hide glues, but Old Brown is the only one I've heard good things about from instrument makers.

Have a look at Mario's vid as to how quickly he can do it.

[youtube]https://www.youtube.com/watch?v=y2SuYAYJ5oQ[/youtube]

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http://www.bobmatthewsguitars.co.uk

Thanks all for the input! It seems that I need to reheat it as I do not want to have a weak joint. My backs are very thick (near .25") so getting heat to that joint would likely be more challenging than the soundboard.

I wonder if it is worth the hassle. I have been using LMI white glue with good results, but the hide glue is just so good!! I can't help but wonder if it would improve tone a bit. When I switched to using hide glue elsewhere (bridge, braces, etc.) there was a noticeable improvement in tone. It may sound like hocus pocus to some, but I tell you it is true!

Bob, I cannot view the video as good ol' GEMA in Germany will not allow it. Can it be viewed elsewhere? Is it possible to briefly outline his methodology?

Any other ideas on how to re-activate the glue would be very helpful.

Thanks!

He starts with the box (sides with back already glued on) in an outside mould, and the soundboard in a radius dish. Uses a heat gun to warm up the rim, and squeeze bottle to apply glue. Then picks it up, flips it over, and sets it down on the soundboard using some kind of locator pins. Presses down on it a few times to squeeze out the glue, and then clamps it down with go-bars. The whole process is 3 minutes, and it's about one minute between the first contact of glue to the rim and the pressing down to squeeze out glue.

I just use a hair dryer (well, actually a heat gun, but that's a bit hot so go carefully). Heat the affected spot, add a little more thinned glue if the gap is large enough to merit it, then clamp. I see squeeze out from the glue already there if I'm doing it right.

This even works the next day, but ideally I'll sort out all the gaps within a couple of hours of the initial glue-up as I think the glue already in the joint reactivates less easily (unless you add moisture) as time passes.

John Greven -- Page three

http://www.grevenguitars.com/pdfs/MartinMyths.pdf

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Ken Cierp

http://www.kennethmichaelguitars.com/

I use a small steam generator to reactivate any areas that gel to quickly. Usually that is only a problem with repairs and not new construction.

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Steve Smith
"Music is what feelings sound like"

Is that Waylon Jennings Mario has on in the background? Maybe that's the trick.

Here's another one he did https://www.youtube.com/watch?v=TC78Z9zFG0I

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I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Alignment pins make for a quick and accurate glue up. Installing the pins is a bit time consuming but glue up is a breeze! When you have the pins to hold the parts in position you can clamp immediately and with confidence.

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http://www.cushmanguitars.com/.

A man who carries a cat by the tail learns something he can learn in no other way.
Mark Twain

+1 Alignment pins make things so much easier.

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Steve Smith
"Music is what feelings sound like"

It's not a problem if you know what you're doing.
If it's not for you, then no problem. It has been done that way for a long time though, and it is the way I was taught to do it by a professional.
Same goes for HHG joints in tops and backs, by the way. I join them with a rope and a wedge. Before inserting the wedge I reheat the glue with the flame.
In my opinion it's just good practice when using HHG: if you can't preheat the parts to be joined, you have to reheat the glue afterwards.


when you reheat with the flame, the heat penetrates the wood quite rapidly, especially in dark wood like rosewood. So I don't think that is a real problem.

If you watch Mario's videos, you can see it is a practiced dance. So, practice, over and over till you get the time down. Get the shop warm too. At 70* F, you have about 90 seconds to get the job done. A little more if you heat the parts first. If you get the shop temp up to the upper 70's you have about 2 minutes to get the job done. 2 minutes is a lot of time. It's amazing all the stuff you can do in 2 minutes. If you are worried about whether you were quick enough, a clothes iron is a good solution for re-heating the joint. Remove clamp, iron, re-clamp - section by section.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Hit the mating surfaces with hhg. Let it dry. Now take your time and make sure everything is positioned exactly. Clamp it up, check the position again, and then hit the joints with steam.

http://www.bedbathandbeyond.ca/store/pr ... aQod5CIAvA

Steve

Yeah, you can even do it this way intentionally. IIRC this is how cellos are glued. I've used it before on a very large zither thing. The trick is to let the HHG grab and gel but not dry before hitting it with an iron. If you wait too long it won't work. About 5 min worked for me.

Mission accomplished!!

I used the methodology from the video, but used clamps instead of the go-bars. My wife also helped with the clamping so it went very well and without problem. Wow, I was really overthinking it!

Thanks as always for the wonderful and prompt help. I really appreciate it! You guys are the best. Now back to...

That's the same steam unit I use now - works great.

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Steve Smith
"Music is what feelings sound like"

If you use spherically dished workboards, it can go pretty fast and easy. Get the parts to fit perfectly. Put the plate to be glued (top or back) face down on the appropriate dished workboard. Heat the parts with a heat gun. Put more than enough glue in the appropriate spots on the plate (more than enough preserves more heat than just enough). Put the rims (inside the mold) down on the plate. Put the other dished workboard on top of the rims, then a weight on top of that workboard (I use a toolbox). If the parts fit well, the glue will suck the parts together, so strong clamping pressure is not needed. The parts just need to fit perfectly.

If you want to use something like Old Brown Glue to extend the open time, you can make an equivalent glue yourself by adding urea to your regular hot hide glue. I have not yet experimented with that, but I recently bought some urea to allow me to do so. Using the above approach, I have not needed to extend the open time. I am thinking a longer open time might make the use of HHG for bindings and purflings a bit easier, so that is my focus re: the use of urea, not gluing tops or backs.

Fish glue for me, works real nice and plenty of time to waste doing it. I love Hide glue for bracing but not for other tasks.

Fred

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

I once had a bottle of Old Brown Glue. I let some dry in a dish. It was like rubber. I could mold it and bend it with my hands after a week. I'll never use any on a guitar, anywhere. I'm sure it's probably strong enough, I just don't like the end product when it dries. I want my joints with glue that gets hard and transfers vibrations from one part to the other. If you need a glue with long open time, use fish glue.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

According to the web site, blobs of glue form a waterproof skin that prevents them from drying out, but the glue line itself is thin and the wood absorbs the water from it, and it should dry hard like normal hide glue. I'll try a couple tests. A blob for long term study, and a thin layer on wood to hopefully dry in a reasonable amount of time and get a feel for the hardness.

I have thought about using fish glue for this too, but I've heard to many stories of it falling apart in high humidity...

It really wasn't a blob. I had put some in a little cup to spread with a brush. When done, I brushed it around in the container so there was a film all around. There might have been a thicker coat in the bottom. However, even the thinnest film did not dry hard. Do that with Hot Hide Glue, and it all turns quite hard. You can't bend it at all. It just breaks. The film from the OBG was very pliable.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

If you do that with HHG it is hard alright! I left some in the bottom of a glass jar (about 1/8" deep) and forgot about it. When I found it a few weeks later it had chipped a big chunk out of the glass bottom of the jar as it shrunk while drying. That is some strong stuff!

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Bryan Bear PMoMC

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

HHG is very strong stuff - we used to make "glue chip" glass at a custom stained glass studio I worked at. We would sandblast the surface of the glass, flood with a thin layer of HHG and let it dry. Overnight the HHG would shrink and pull the surface of the glass off creating a beautifully random paisley-like pattern.