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Hesh, I wouldn't yet say that the binding material makes a difference but binding does. And I'm talking about a guitar with no air leakage prior top binding. And I was very skeptical before I acutally tried it.

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http://www.chassonguitars.com

JJ, it's just a hunch... But feel the edges of a top, and they're often nowhere near as lively as  center of the sides' are. And on narrower instrument, the sides don't seem as 'involved'.

Again, just hunches. If I had all the answers, I wouldn't be here <g> It's also why I read everything Al puts forth...

 For the bindings, even those of us who don't use kerfed linings notice it, s it's not about air leakage.  I think it's a tension issue, where we release tension when cutting for the bindings(the whole gets looser, dropping in pitch, then through the use of water based glues, add tension when the glue dries and pulls things tighter(not to mention the effects of all that clamping when we installed the bindings). Or we can take a page from violin makers who often only glue one edge of their purflings, allowing for a looser plate. What Taylor's now doing with their little slot they cut under their tops, more or less.

It's even been argued that part of the "vintage" tone of old guitars comes from the celluloid purflings shrinking a bit and disconnecting themselves from the top, freeing it up further.

geeze, is it cold and snowing everywhere today?

JJ bro I think that Mario might agree with me here.

There are vibrations that travel through and along the wood but there is also the pumping action of the guitar body that produces sound pressure - not unlike a shock wave but millions of tiny shock waves.  These high and low pressures inside the box are impacting the entire inside of the box and this is how the air inside the box transmits vibrations to the sides and back.  Of course the sides are also excited by conduction with other parts, the top, back, blocks etc.   But the sound pressures generated by the pumping action of the guitar some of us believe are more responsible for vibration transmission to the sides then the joint with the top.

Other, the double side guys, are nearing taking the sides completely out of play and counting on an inner layer of highly reflective wood on the sides in favor of the benefits of an ultra stiff rim.

Kent  - got it, we agree the binding material is not an big influencer.  Now I understand you to say an unbound but "sealed" box sounds different then a bound box.  I always expose some kerfs when I cut my binding channels so I have not had an opportunity to notice this.

I feel that the argument has settled into a circular orbit again! Even though you can't "feel" the vibrations at the stiff corners like you can feel the movement of the more flexible center portion of the sides, is there no energy transmission through the denser material? I submit that there is...and that's my "hunch" as well. But how do you measure and compare the solid energy transmission against the air pressure transmission to the sides?

It's time for Al to provide a little acceleration for us to achieve a higher orbit and modify our hunches if possible!

Good stuff...

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JJ
Napa, CA
http://www.DonohueGuitars.com

I've been securing my tops on with double stick foam weather stripping
for years now, and never noticed a difference. Sure makes for ease of
serviceability.

If you do want to use hide glue however, just make a portable go-bar
deck and get a membership at the nearest gym with a sauna.

Really though, I'd tend to side with Mario, Hesh, and others that although
how the top is secured to the sides certainly influences tone, the
difference between a well fit, single molecule layer of hide glue vs. PVA is
likely to show too little a difference in results to qualify as significant.

And if you do want to use hide glue, the sauna was only partly in gest. I
have a few violin maker friends who have used or still do use a hot room
for gluing plates to ribs. A small room heated to 110-115F, and you can
take as much time as you like. It's not the most comfortable room to work
in, but they're generally not in there for more than a few minutes at a
time.

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Eschew obfuscation, espouse elucidation.

The old Spanish builders had a way of joining the back to the guitar (the top was attached with dentellones) that enabled them to use hide glue.

Spread the hide glue on the rims and back braces (they already had the back braces attached to the rims and glued the back to the rims and braces at the same time). Place the back on the now gelling hide glue and brush alcohol over the back above the glued sections, set fire to the alcohol!

The heat from the combustion was enough to soften the HHG and they then roped the back on.

Joshua and I have been daring each other to have a go at this.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Now Colin, maybe the Spaniards could treat their alcohol supply so
flippantly, but can you imagine an Irishman wasting their single malt in the
name of a good glue joint?

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Eschew obfuscation, espouse elucidation.

"Old Smuggler" in the plastic 2 liter bottles is the better choice.

As for double stick foam tape, I've found bubble gum to be far superior. But only fresh "double bubble" brand. And watch out for wax contamination from the wrapper.

But seriously, I'm pretty interested by all this because I think that, compared to a lot of the nits we pick, this area of the box has way more impact than it's generally given credit for. And I've never heard a lot more than hunches on why or how.

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http://www.chassonguitars.com

For gluing the sides to top or back to the sides, I use the same method as cello makers...heating one workable section at a time -warming, gluing, clamping and then on to the next section. Hide glue is perfect for this application as each section blends in into the next.

There is no reason to go hell for leather trying to get the back glued in time. Work smarter, relaxed and in controll of what you are doing. Double Bass and cello makers have been doing this for years.

Tony would you please elaborate on this/your method?  Thanks.

Hesh, you take a warm, thin knife, and feed the glue into the joint a few inches at a time, clamp, feed more glue, clamp, until you go all the way around. It's about the only way to close a cello or bass(as well as a Weissenborn <bg>).

What Mario said...

I use a flat bush at first then (when most of the back is clamped) a knife and clamp in sections using spool clamps and sometimes flat rope on my workboard.

Using a go-deck like Mario is not an option with the Hawaiian Style vaulted back of a Weissenborn. This was the technique used on the old Weissenborns, and works for me also.

Seeing a cello maker in action with this tecnique is really something!

 

That, or the sauna. You can glue up a bass in a hot room, and have about
as much time as with Titebond. I know this is still used among some
bass, cello, and piano builders using hide glue.

It sounds extreme, but when you consider that the coldest sauna you'd
find would be at around 150-160F, keeping a room that you'll be in for
10-15 minutes at 120F doesn't seem so bad. Even a temporary room can
be made with a few 4'x8' reflective foam insulation boards tacked
together, and an electric heater or two to bring it up to temp. As soon as
it's glued up just pull it apart and stick the foam in the rafters.

Still, all things considered it's still a lot more work than laying on some
PVA. And unless you're doing a batch of several instruments at a time it's
probably much more work than the sectional method Tony and Mario
mentioned. Plenty of ways to skin a cat.

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Eschew obfuscation, espouse elucidation.

I just got some hide glue from luthiers mercantile. Next week i'm gonna experiment with it since i never used it before.

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Guitars, guitars and more guitars.

If you have ever spent much time restoring new and vintage instrument you would know using hide glue brings good karma!

Thanks Mario, Tony, and David!

This is somwhat similar to the way I glue kerfed liners and bindings with HHG...except I don't use the knife. It's a continuous process and they're clamped or taped as I go.

I really don't see the need for the sauna room...at least for HHG gluing!

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JJ
Napa, CA
http://www.DonohueGuitars.com