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I am curious about which plate you glue on first and why. Presently I glue on the back plate first so that I can easily clean up any squeeze out on that back/side joint, (the joint you see) and because I want the top surface to be more stable before I glue the top onto it. I worry about that back plate stressing out the top, maybe torqueing out the sides when it is glued on. But, I can see good reasons for doing this the other way around. (like having the top set for final tuning before the back is put on)

So, I would like to know what is happening in the wider world of lutherie outside my clannish top.

Thanks
John

Ah that last sentence should read "clannish mop, ah shop "

John I do the same as you, for the same reasons.

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Lance@LuthiersForum.com

ditto. back. cleanup.

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John Mayes
http://www.mayesluthier.com

Me too, back first.
Though I've thought about making some sort of dummy body that the top can be attached to to make tuning more accurate (ala Ervin). But that hasn't happened yet.

John,

Apart from Weissenborns, I glue on the back first and then the top - for the cleanup issues that everyone else has mentioned. Before either set is glued on, the rimset is such that the back and top are both ready to glue on so I could do either. I also take a lot of care to ensure that the top and back plates fit the rim perfectly without any need for clamping pressure to keep them in place - this means that I can use the brown binding tape around the top and back as my "clamps".

This is one reason I went to X braced backs - it gives me side to side and front to back curvature without having to force back onto the sides to give the front to back curvature. It's also one reason I use wooden side braces and the cf butress braces - the rim is totally rigid. Others use laminated sides for the same effect.

I'm afraid I personally learn very little in terms of brace tuning with the top on the rim and no back on. I do my brace sound shaping on the free top. Without the back on I can't hear a lot and in fact it's not until the binding is glued on the closed box that I start to really hear the "true" sound - just gluing these on makes a fantastic tonal change I find.

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Guitars, back first.

Mandolins, top first. I'm using the straight, pinned mortise neck joint on the mandolins so you have to, otherwise I would do them like the guitars. The cleanup issue is the reason for me as well.

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Rian Gitar og Mandolin

     I install the back first and to be able to clean that joinr up easily as well.

     I've always been cancerned about any distortion that may be caused by
the clamping of the back so I've always done a quick redress of the top
radius withthe dish after the back is in place and before the top goes on.

     It's always fun to hear that others are concerned about the same small
things that I am. It confirms the fact that I'm not insane for sweating small
details.

Reagrds,
Kevin Gallagher/Omega Guitars

Dave you make some interesting points about the top and side glueup not being good for plate tuning. However, I have noticed that I do not lose the ringing taptone in the top until after I route the binding channel. It returns of course after the binding is glued in. I am wanting some way to tune the top, a-la Ervin after the edges are fixed in some way. I guess I could do a solid rim clamp but that means making one for each size guitar and I was trying to avoid that.

Kevin
   I am glad to know that you are concerned about that distortion thing too. I also redress the top rim after the back is glued on. However I am not sure my company insures sanity.

[QUOTE=John K] Dave you make some interesting points about the top and side glueup not being good for plate tuning. However, I have noticed that I do not lose the ringing taptone in the top until after I route the binding channel. It returns of course after the binding is glued in.[/QUOTE]

John,

I have been listening a lot more lately to the sound of the top at the various building stages. The first thing I have noticed is that the top only becomes really "alive" when the upper transverse brace is glued on. The change is noticable and remarkable. When the top is glued on to box this goes away - the top still rings but not with the "alive and kicking" feeling. When I route the binding channels the ring goes down a little but not hugely. When the binding/purfling is glued on the top is "alive and kicking" again - a very noticable and remarkable change to my ear.

The more I listen to the sound of the box the more important the use of binding and purfling becomes apparent to me. My current "theory" is that the bindings enclose the top - the bindings pushing in from the side tightly and the purflings pushing from the top as well - rather than the top resting on top of the side with the box initially glued up. This enclosure makes the top behave more like a drum - I think the bhodran analogy is a good one. The purflings may also perhaps induce a little more flexibility around the rim.

This may be associated with my building style using big arching in the top as I have not heard other builders comment in similar ways on the changes.

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

I too glue the back on first then check the fit of the rim in the dish for the top, and adjust if necessary.

Like Dave, we've been discussing this, I think that the final tuning of the top can't really be done until the binding is on, especially if using HHG or fish for the joint as this pulls the joint tight changing the tensions on the top. Also, until the bridge is glued down the top is incomplete, it is after all the most massive brace, so again any tuning is only guesswork. So, unusually I know for steel string guitars, I don't finish the top until after I have glued the bridge on and strung the guitar up. I'll often then thin the lower bout till I get the response I want. Then a quick FP for the top.

Colin

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

I have mostly gone against the grain and glued the top first.
In my mind, it was important to “see” the gluing of the top to the sides to assure a solid joint. As techniques and confidence have improved, I could see switching to the popular approach.
However, this leads me to a related question.
Is it essential for the sides to be clamped into a mold in order to glue the back on first?

Great thred guys!
interesting info about the binding..

Wade

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Wade
Nashua, NH
http://www.wadefx.com

Same here, bro. Same reasons.

KBW

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From Nacogdoches...the oldest town in Texas.

http://www.stephenkinnaird.com

Since I build classicals in the Spanish method, there is only one way and that is top first, face down on the workboard.

     John K's post above about the resonance of the top....or the body
going away when the steps for the binding are cut and coming back once
binding is glued in place raises an interesting point concerning the
function and behavior/cointribution of the sides to the tone creating
system that the assembled body is.

     I've always been of the belief that the sides act as far more than a rigid
support rim between the top and back and this loss and return of the
resonance that is typical.

    If they were only a static rim that holds the top and back at the desired
distance from one another allowing the reflective properties of both to
work together as they are activated, the reflective abilities would not be
depleated as the joints between the plates and the sides were relieved by
cutting the binding steps, but would remain intact along with their
effects.

   I've always felt that the sides are activated into a state of vibration by
the top's vibration being directed into them. The sides, in turn, vibrate
the back through direct contact at it perimeter, creating much of the
voice of the guitar or color of its tone, hence, presenting the difference in
tone between a Mahogany and Rosewood back and sided guitar with
identical dimensions, materials and appointments otherwise.

    Back and sides are chosen for much more tha their reflective
capabilities and appearance, in my opinion. Reflection would not be
enough to generate the radical variantions in tone from one species to
another, but their vibration and the efficiency with which they are
activated is much more responsible, in my opinion.

    This is only part of the sequence that occirs to generate all of the
vibration that becomes the sound and tone that come out of the
soundhole and off of the top of the guitar. Another important
contributing effect of the vibrating of the top by the strings being
attacked is that the top activates the air inside the body cavity as the
soundhole controls its release according to its diameter.

    The soundhole can determine many of the subtle things that make a
guitar sound like it does. Its size determines part of the guitar's
fundamental note resonance. A smaller soundhole lowers the note
generated while a larger hole allows a higher note to be created.

     At the same time, I believe, the soundhole's diameter determines how
long the rapidly and violently vibration air inside the guitar is contained
before it can pour out in an effort to relieve the pressure that is created
inside the body cavity by the pumping effect of the bridge's rocking
action and subsequent movement of the top.

    I've always believed that air held longer inside the guitar's body is able
to further affect the back and sides, thus, allowong them to contribute
more of their tonal contribution to the guitar's overall voice.

    These are just some things that i've observed in guitars from all the
major manufacturers and alot of small builders as well over the decades
that I've repaired and built instruments.


   Sorry for the change in direction in the thread, but I thought it would be
interesting to see what some others feel about these things. I'm sure
there could be as many opinions as there are commentors, but that'swhat
makes it so interesting....to me at least.

Thanks,
Kevin Gallagher/Omega Guitars

Interesting post Kevin

I had always thought that the resonance went away when the binding ledge is cut because the hinge was affected in a way that muffled the vibrations when they reached the perimeter of the top. when the binding was put back on that too soft hinge was re-stiffened and the top had a more metallic ring just because the softer kerfing was reinforced.

But, that may be an incomplete view. You are probably right about the vibrations traveling through the sides to the back and that the ledge uncouples that path stranding the top on its own with out reinforcimg vibrations of the back and sides.   Or sides and back if order is significant.

I am wondering if the top was clamped into some kind of perimeter clamp, the way Ervin does, (before it is glued to the rim (of course) would it sound the way it does before the channel is cut or after the channel is cut. If the former, then what does this say about the side as a contributor to vibrations.

(I can't find my glasses. I sure hope my fingers wer indexed correctly over the keyboard.)

John

Wade
   I almost always clamp my top into a mold for both plates, just to insure the sides are straight with each other, if that makes sense. I would like the sides to be parallel to each other. If you look at the end of the guitar sighting down the humps of the upper an lower bout they really should be in tje same plane

I meant to say I clamp my sides into a mold when gluing on both plates.

But Hesh, you have a really big (comparatively) hole built into the top that pretty much stays there. The small openings between kerfs seem to me to be insignificant compared with that.

All the little kerf slots act to deflate the top like a leaky air mattress - they need to be closed to keep the air pump working. I notice the same thing on all my guitars as well, as I too reverse kerf and then route thru the sides most of the time. Put the binding on and again it taps/rings fully. As well, the soundhole is usually slightly in front of the waist - such that the air in the lower bout must squeeze by the waist increasing in pressure (possibly - maybe I am completely off base here, but it sounds cool to the unknowing layman !!) slightly to get to the soundhole - all the little kerf holes in an unbound guitar defeat this effect

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"