Official Luthiers Forum!

I thought you guys would get a kick out of this. Me –- i'm kicking myself. I was assessing the crossgrain stiffness of this torrified top from StewMac, when SNAP! Just like that it broke into two pieces. It's my own fault. I should have known better.

FWIW, the tap tone was really nice, but I have several other non-torrified tops that are stiffer.

If it was up to you, would you choose the top with the better tap tone or the stiffer one? I realize there's no simple answer, but am curious to hear your thoughts.


Sent from my iPad using Tapatalk

As I always say... build a harp ukulele out of it, or send it to me and I'll do it

IME, cross grain stiffness is largely inconsequential. The value I care about is Young's modulus along the grain divided by density. But which is more important between that and tap tone? I'm not sure. Nylon strings need both, but with steels there are plenty of ways to make less stiff wood work, and tap tone doesn't seem to be essential either. They're just two more variables in the overall mix.

It depends (of course) on what you mean by better tap tone. The stiffer top will ring higher and probably longer due its probability of higher density. Super stiff tops can be really heavy and it's easy to add stiffness to a lighter top by leaving it just a touch thicker which will more than likely make for a lighter overall top than a stiff heavy piece of wood. Of course there are outliers to these generalizations.

_________________
Jim Watts
http://jameswattsguitars.com

Glue it back together before it starts to relax, not going to get a better fit.

Yep, glue it and go

Yep, should be invisible -- pva's and hhg glue lines are stronger than the original wood (assuming a perfect joint)

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

One of the best guitars I have built used a top with a tap tone that sounded like wet cardboard. I came real close to not using it based on that metric but went ahead with it anyway. Could have been a lucky one off, correlation not causation kind of thing I don't know. But it has me thinking that tap tone is rather meaningless or if it does have any meaning at all then what is it?

Is there a general consensus out there that torrified tops are more brittle?

I've built two guitars with torrefied tops and learned quickly how easily they crack. Always glue them right away and all will be fine.


Sent from my iPhone using Tapatalk

_________________
"It is easier to fool a man, than it is to convince him that he has been fooled"
Mark Twain

I've worked with torrefied maple and it is definitely more brittle. I'm sure that would carry over to most wood species.

_________________
Steve Smith
"Music is what feelings sound like"

I did nearly the same thing with a torrified sitka top, dropped while thickness sanding and it went down with the caddy. The weight of the caddy socked the corner of the top when it hit the floor and suddenly I had to pieces instead of one. It was a very clean break, glued it back together with HHG, completely invisible. Built up to a nice guitar.

I've built several w/ torrified tops (SM Sitka) and while it makes a great sounding/looking gutiar, no doubt it is brittle stuff. I've split the grain several times at the edges just picking the guitar up. I "think" it is okay once built up, but confess I worry about it.

Would you worry about it?

_________________
Craig Bumgarner

Bumgarner Guitar Blog

Not a "one off". I have built many a dang good guitar and mandolin with softer tops, A grade and off quarter too. I would never have built with "horrified" spruce though, preferred natural red spruce myself.

Likely I don't have a clue, but I've always did/do my final brace shaving and tapping after the top is assembled to the rim, I listen for resonance and decay -- to my ear there is no mistaking that nice "bonk" that lingers when a sound board is moving freely --- and again it just might be my imagination. But, point being a flexible sound board can be braced a little heavy and adjusted accordingly with brace shaving.

Here's food for thought ----- currently there are 605611 posts at this forum --- try and find some or one where a maker proclaims they have constructed a really "crappy" sounding guitar.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

I agree, once it's assembled the tap and resulting sound are indicative of tone. But the unbraced slab is meaningless to me. I've adopted the deflection testing method to make unbraced tops meaningful and since I only just started that 3 guitars ago I have a long way to go before I can determine its value.

I am going to go on record to be the very first, perhaps, to say that... I <state your name> have built a crappy guitar

It was my first and only double top guitar. Talk about tap tone? Well the double top alone felt like it was already braced. I think I over braced it. One day I may retop, it was all an experiment anyway. Come to think of it early on when I first started and had no business experimenting what so ever I did experiment anyway on a Kasha inspired... something or other, and it was pretty crappy too. Fortunately that one was built with a retop in mind in case it sounded bad, which it did, and as such has come full circle to a guitar my nephew now enjoys.

I've also also built a crappy guitar - a size 0. Top was too floppy. It got retopped and is nice now.

_________________
Steve Smith
"Music is what feelings sound like"

Probably most of us have built crappy guitars and just didn't report it. My 3 worst sounding:

16" lower bout, thick sitka top, lightly braced. The raw top's tap tone wasn't that great, and correlated with the guitar's tone. It wasn't exactly bad, but very mellow, sort of poofy sounding. It survived structurally, but did have a bit too "sharp" of a belly right behind the bridge than I'd like. Bridge possibly would have come unglued after a few years. This wood possibly could have been made to work by making it thinner, and stiffer braced, or smaller guitar.

15" lower bout very thin sitka top, which had great tap tone before thinning. X braced with large bridge plate and south quadrant lattice. I carved the braces too low around the perimeter, resulting in very good bass and very bad trebles (hollow sounding). The soundboard pulled up significantly under string tension so the perimeter area was highly curved, while the center remained more flat, but playability remained good for the couple years I kept it around. This one's bad tone was my fault, not the wood.

Small nylon string, 11.3" lower bout but with full 25" scale. Engelmann top, spalted maple back/sides, both with bad tap tone. Over-thinned the top, to about 1.5-2mm. 3 fan braces. It was very quiet, very mellow, and no sustain. Possibly could have been better if I'd left the back/sides thicker and more stiffly braced to reduce energy drain. Possibly could have been better with thicker soundboard and skip the fan braces. But I suspect the woods themselves were more to blame.

"Here's food for thought ----- currently there are 605611 posts at this forum --- try and find some or one where a maker proclaims they have constructed a really "crappy" sounding guitar."

Didn't the folks at Martin say something to the effect that they didn't worry too much about voicing because someone will find the sound of the guitar appealing. And how many mother's will say they have an ugly baby?

Please don't ask my mom that question!

_________________
Bryan Bear PMoMC

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

Yep -- Bob Taylor indicated something similar as well. As for guitars --- "sonic beauty" is in the ears of the listener.

Sorry seems I pulled this thread way off topic.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

You can ask my Mom. My brother was the ugly baby.

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker

Nah, I think MIke got the answer he was looking for, glue it back together and carry on...

---

I admit I purchased some torrified tops, Adi tops, to one day give it a try even though I was adamantly against it for a while. The only way I can overcome curiosity is to try it myself.

I am however still sort of concerned. My day job is in IT and we always let the latest and greatest get bug tested out there in the while before adopting it. Same sort of thing, but I made the first step!

Crappy guitars. First guitars I made out of flat sawn pine, made up a bunch of sides and backs. Made two of them with cedar tops, turned out ok. Finished one pine toped one, sounded like crap. Sister wanted to mosaic them so I finished them off and gave them to her. Practiced doing a rattle can burst on one.



A question came up about putting nylon strings on a guitar braced for steel. Common wisdom said it would be too quiet. Since I do not seem to have much wisdom I had to find out myself. Grabbed the guitar back before sis stuck stuff on it and put some strings on.



A little down in volume but playable. Ended up making a lefty out of it and giving it to a woman that was waffling on learning to play guitar.

On the baked tops, I am wondering if people are overdoing it a little on how long they leave it in the oven. I have cooked a few pieces and you can tell the difference on how TB beads up on it but the wood still has the consistency of wood. I do like the smokier color the wood gets and I have heard an increase of the tap tone. Originally wanted to give the process a try to see if I could make the wood more stable with humidity changes.

I am making a few maple guitars, thinking of doing two with baked tops and two without. Not identical tops but they do look like they came from the same tree. Will have to bake the two then decide. As far as floppy wood, another hare brained experiment is using flatsawn crappy wood and see how it will sound. Still looking for the right piece of wood for the back on that one.

Oh yeah, the sunburst is gone now.

Yes! I've glued the snapped top. I think it's going to be useable! Phew. Thanks for the help and insights.