Official Luthiers Forum!

Oh Flipo...my role model...wish me had your tack and communication skills. But hey...me still gets the point across.

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I've heard it said 'there are two types of woodworkers: those who understand how wood reacts to changes in humidity and those who soon will'

Right. Hey... If it weren't for mistakes, what would we have to learn from?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Reading about other peoples mistakes on OLF...

Amen!

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Audiences and dispensations on Thursdays ~ by appointment only.


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My philosophy used to be that if I paid attention, I could learn from and avoid the mistakes of others. Turns out, I just made new and different mistakes!

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Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Isn't that how life is? I think that is where the saying "Live and Learn" came from.

It reminds me of a quote I heard once:

"Live and learn from others mistakes, you cant possibly live long enough to make them all yourself..."

Cheers,
Bob

So... A light bulb is twitching a little bit. Now that I think about it, I ended up having to fix a couple side cracks in the same place (since they are booked matched). The middle wedge was a consecutive "slice" from the same slab of blood wood. I think this particular part of the board just had a plan to crack. I never can see these things until they happen. Are there any tests to find things like this before resawing, bending, etc.?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

I don't know first hand but I do a lot of reading about building and techniques and from what I understand you should stress test wood before using it. That ranges from just bending it with your hands to putting weights on a piece of the wood that is supported between 2 risers.

I am sure someone here knows what I am talking about so it would be better to get input from someone that does it.


Yea, If you had cracks that you already repaired and it was from the same piece of wood that probably is part of the reason you had such a large failure of the back. But the humidity issue is what caused it to pop.

Bob

There is nothing wrong with being original and creative in your work. Even if it is with the mistakes.

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PMoMC

Thats My Motto ! There not Mistakes they are Design Experiments !

Clean out that crack a little wider and bind it and you have a "Back Soundport "

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The Shallower the depth of the stream , The Louder the Babble !
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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 !
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Wud, when you make it look intentional, that's when it changes from a "Design Experiment" to a "Design Feature!"

Yeah, plenty of experience there...

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Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Bloodwood is simply brittle like that... like Indian or Gabon ebony, or a lot of Brazilian rosewood for that matter, it'll split along the grain if you give it any excuse to. Maple, rosewood, mahogany, etc are tougher to split and may have not cracked like that, but they would've been under the same stresses when the humidity dropped so low. If you're going to use brittle woods you simply have to build under controlled humidity and not expect the guitar to survive really dry conditions. If you need a guitar to survive those conditions, use a tougher wood that is really stable with changes in humidity (or plywood!), but know that every wood has its limits.

Ok the other thing not being mentioned about building with Blood wood...and very very few do this is to lamb it up into ply. End of any splitting problem.

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Audiences and dispensations on Thursdays ~ by appointment only.


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That reminds me. What exactly is the purpose of a sound port?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Can you explain this process? I've never done this but I hear it's a useful technique. How thick are the plies? I'm assuming you laminate before you bend instead of after?

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

just a reminder- the title of this thread asks, should the owner "smash" it? as an amature who has seen a few photos of cleats and not much else, anywhere, practicing this technique SEEMED like ONE POSSIBLE use of the cracked instrument, rather than flattening it outright. perhaps it would be more constructive to the forum to say something like, "Nyazzip, cleating a crack like this would be a lost cause because of A), B), and C)", rather than the condescending ego tripping and self congratulation.
you have time to type "no, terrible idea, go home", why don't you type a sentence explaining to me, Alex and Fillipo, why YOU THINK it cannot/shouldn't be cleated. in hindsight i can see that the back must be detached from the braces; is this why? is this one rerason why, or the entire reason? me and a whole lot of other amateurs wouldn't mind knowing.

Hi nyazzip,
If you re-humidify the wood and the crack closes up and can be closed with light to moderate pressure, then gluing and cleating the crack can work. If the guitar was built under high humidity conditions any time it experiences low humidity, stresses will occur that will want to make it crack again. If the guitar has been under unusually low humidity and cracked, then repairing it and insuring it never again experiences those conditions may make the repair successful.
If the two sides of the crack have shrunk and distorted and it can no longer be closed up, then a splint may be necessary to fill the void.
On a new instrument it may be better to just replace the cracked panel rather than repair it.
Some repair people can do amazing work making cracks disappear (i'm not one of them) and what some people say can't be done, others do.

fillipo, my initial, original word-for-word response was: "rather than smashing it, you could probably practice some cleat-laying techniques on it if you can get the gap squeezed shut, no?"

key words/phrases: "you could probably"; "if you can"; and finally the non-assertive: "no"?
...what exactly is wrong with "conjecture and hearsay"? are you a robot? how did you ever learn anything, without inviting discussion and entertaining possibilities?
when someone is considering "smashing" something that most of the world couldn't afford to have, i feel at liberty to make polite suggestions. your arrogance amazes me.

sorry man, my apologies. i truly respect your work and a good 90% of what you say. cheers.

And the thread is officially hijacked

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

I have fixed big cracks before. I removed the back, and removed all braces, closed the crack (after that back has had time to acclimate to 45% RH), reglue the brace, and cleat it if necessary. That was on an old Stella copy (Not Stella, possibly Galliano or something)

If you want to save the wood, you will need to remove the back and acclimate it to a standard RH (45%) and brace it under that condition, after fixing the crack of course. The back will most likely have shrunk and it will NOT grow back (it was said wood that shrunk due to low RH doesn't really grow back) so you will have to trim your braces to fit before gluing that back on. If you are unable to close the crack after removing the back, you will have to fill the void by inlaying the same wood into it.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
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So, I finally got around to fixing this thing. I was dreading it (no pun intended), but I had a little time and figured it had been long enough. The back came off without too much trouble.



I found a piece of bloodwood that had really straight grain. Since I currently only have a bandsaw that will barely resaw a 6 inch piece of wood I made a three piece back out of it. Because the joints are so tight, it almost looks like a one piece.







Glued up the same way I did the original.






When I first got the new back on I wondered if it was as good as the old back in sound. When I first tapped the instrument it didn't have a very inspiring sound to it. After attaching the bindings and getting everything sealed up so I didn't have a bunch of tiny little vent holes from the kerfing, it started to sound right.

This whole build has been a great lesson not only in relative humidity while building but also in the role the back plays in the overall sound of the instrument. I got to hear it when it was first put together, with that nasty crack all the way up the back, without a back, with a back and a bunch of little holes from the kerfing, and finally sealed up with bindings and all.

Thanks to everyone for all your help. On to the next one.

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"I'm not going to say that perfection has never been achieved. However, if it has, it probably went unnoticed due to it's lack of character."

Sweet. I love seeing a follow up post to a problem like this. Thanks for updating us. It gives courage to the next guy who has a boo-boo that needs some major re-doing.

Your finished guitar looks great. Cheers!

Yeah closing the little binding holes makes all the difference in the world doesn't it. That back looks great. So did the original one but oh well that's the way it goes.