Official Luthiers Forum!

So I decided to re-bend my set of coco so that it fit snugly into the mold because it didn't seem like it was close enough for just spreaders to fix. Soon enough, I hear a cracking sound that ruins my day... So what's the verdict? Is this at all salvageable or should I go ahead and order a new set of sides (and probably a back to match)?




I must say that this is quite the setback... <sigh> Anyway, you can see the visible crack is very small, which is why I'm wondering if it can be saved....

Michael buddy I feel your pain. This stuff happens and it happens far more frequently than you might think.

Although I would not attempt to fix this one some might. I would always be worried that the fix would give way after finish is on it and that would be a nightmare.

Depending on where you bought this set many sides and backs are not from the same boards anyway and are simply matched visually for a color match. It seems to me that you could get another side set from the original vendor and ask them to match it to a sample or picture that you provide.

Also I wanted to ask you if you are thinning the cut-away area additionally to make it easier to bend? Many builders will thin this area to something like .070ish.

Cut-aways are not easy to bend and you nearly pulled it off and most importantly I am sure that you learned a great deal from the experience too. So in a way this could be considered a net gain if you choose to see it this way my friend.

I wish I could've have gained valuable experience on a cheaper piece of wood...

I don't know if I'll order another set of coco since it seems to be pretty difficult to match color-wise. I might just get some cheaper EIRW or Walnut to finish this build this time around... I suppose I'll hang onto the coco back and see if I use it at some point in the future if it can't be saved. I had thought about maybe attempting to sand or scrape it down a little bit seeing as how it's a bit on the thick side... I don't know, though...

Also, the crack is actually on the inside if that matters at all.. Do you think the structural integrity is seriously compromised? Obviously a crack isn't good, but I'm just wondering how much of a negative impact if I did attempt to fix the problem...

BTW, this wasn't a cutaway. It was actually at the waist of the guitar. I guess I shouldn't have attempted as aggressive a bend there as I did... My inexperience got the best of me.

Do you still consider yourself in a "learning stage" (meaning you're not selling your guitars for $4-$8k yet), or are you producing instruments at a regular pace to fill backorders at a decent price?

For a journeyman or master craftsman (were those titles to really exist), it may be appropriate to replace it - though of course a journeyman or master would more likely be able to make it invisible or rather never had it happen to begin with. If this is your 1st, 2nd, 15th guitar, and you are still learning and developing, I say keep pushin through with this set. - When it's done, it is what it is, and whatever or however it is doesn't really matter much.

If you want to build a flawless instrument on one of your first builds, you'll never get an instrument finished. This time you had a problem on step 7. Start over, you'll make it to step 15. Next kit something goes wrong at step 12 that you slipped by the first time. Start over again and make it to step 35. (with a few hundred steps, you see where I'm going with this )

In a traditional Cremonese violin making school you would know that the fine instrument you spent years building up to completing would be taken to the bandsaw after inspection and critique. I see this as having much more purpose to simply humble a student and remind them of their status. These students are blessed with being forced in to a mentality where the focus is entirely on learning the craft, and not worrying about walking out with a fine instrument. I feel that those two goals clash a great deal when you are building your first few instruments.

I would say try to finish it out. Glue it up with CA, and bend it to match the mold on a hand bending iron. If you have one, you can bend a cracked cutaway like this from both the inside and outside. When heating from the inside (preferred, because 90% of a bend is compression on the inside vs. <10% expansion on the outside) keep a steel backer on the outside. Some supply shops sell these, or you can just screw some handles on to a piece of steel shim stock. The glued crack may still want to come apart from the heat and bending, but if it starts lifting you can bend it back down from the outside.

Sometimes they can be made near invisible, but I wouldn't count on it. Either way, I would go right ahead with the build. If the instrument is acceptable (functionally) when done, sell it to an acquaintance for cost or maybe 2x materials cost, and go on to build another.


Edit: I thought that was the cutaway. It's the waist? Hell yeah, just glue it up and move along. Once you flow some CA in there and press it closed, I doubt you'll have to re-bend much at all on that point. Bend gently focused just to each side of the crack and it shouldn't reopen at all. Bend against as broad a surface as possible to make the final curve - never put heavy pressure on a single focused point. Listen to the wood as you're bending it. Don't increase your pressure to make it bend, keep your pressure steady, rock it a bit, and it will tell you when it's ready to move.

_________________
Eschew obfuscation, espouse elucidation.

David my friend you are beginning to sound a bit like Grumpy..........

Im thinking it could be repaired, or you could at least attempt it to see what happens. Wet it, re-heat, re-bend, then superglue the area, brace/patch it on the inside with some mahogany or ? , use (super glue) and sawdust, fill in the area again, sand, looks like new, use as lower bout on personal guitar.

Worth a try?

_________________
Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I

Too many curmudgeons can throw a forum all out of whack. I've just been waiting for a position to open.......

I think I've found my calling

_________________
Eschew obfuscation, espouse elucidation.

David is right on. Fix it and move on. Throw some CA at the problem. Get back on the horse and learn from the experience. I paid $50K (1983 dollars) for an education that puts me in 6 figures. Blowing a few hundred bucks here and there in this business is a cheap education. Never overreact to setbacks.

Mike

"Also, the crack is actually on the inside if that matters at all.. "

Sounds like New Side set to me....

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

Fix it fix it fix it fix it. No question.

_________________
Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger

I would say quite the opposite, but I wonder if you're reading the description the way I first did.

I misunderstood what Michael was saying the first time, and thought he was saying the crack was photographed from the outside edge of a cutaway, and that it was also visible on the inside. If that were the case it would be an difficult repair.

If the crack is indeed photographed from the inside of the waist (and not terribly visible as a sharp crease on the outside) then it can be repaired cleanly, and without any visible sign of repair or structural compromise. Even if it does end up slightly visible on the inside when done, that's where a side brace goes.

I'll tell you what - if that crack occurred on a set of Brazilian, this discussion would be limited to the "how" and not "should I".

Think of it as one learning experience, among many more joyous ones to come. This is barely an inconvenience - just wait until you run in to some real problems......

_________________
Eschew obfuscation, espouse elucidation.

It is eir nor brw why not try to match it ?

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

O.K. so its coco why not try to match it. I have let things go, but at a commission level I don't think I could.?

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

Because if the end product is not even slightly compromised, visually or structurally, there's no reason to.

Plus if you read my first post above, it's my philosophy that you would progress slower and learn much less as a builder by taking this approach. I feel quite strongly about that actually.

_________________
Eschew obfuscation, espouse elucidation.

Michael I see grumpy's last build to be the example. It can have 3 different kinds of mojo.
on one level it can be the build that went just right and there was no tear out in the figured maple and was the product of a search for a sound and a mastery of how to get there.

A touch of for-ever


2nd mo

tear out on the sides and replaced
Well built with a sound in mind.

3rd mojo

Still well built with tear out

?

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

I played a Chinese guild the other day that had TONE...

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

I've never cracked a side during bending that I haven't fixed and carried on with. Thankfully I've only broken two sides -- one was my very first build, and the other was a recent high figured Koa side that I underestimated -- but I think there is so much more to gain from fixing than starting again, however tempting it is at this early stage of the build.

It's hard to judge this crack from the angle shown, but the feeling I get is that it's not terribly deep and given that it's on the inside, it should be able to be fairly seamlessly fixed. Flood with CA glue, clamp it securely closed and it should be good to go after sanding clean. The area can be easily covered by kerfed lining and side brace.

If I recall correctly it's your first guitar and I think it's great that you've gone for a more interesting back and side wood. You're not selling it, and odds are if you keep at it and complete it, you'll end up with a great looking and sounding guitar. If you want to finish it with EIRW or walnut then by all means go for it. But from the looks of things you've got a perfectly good set of wood right now with a side that can be seamlessly repaired.

To me it's not even an issue of compromising the end product, because if at the end of the day it can be easily repaired without any detrimental affects on the structure, tone or appearance then why not? At the very leasy give it a shot, get the build up to the rim stage with linings and head/tailblocks in place and if you're still not happy with how it turned out you can put it aside for another day when you feel more confident about these things and start over with a new back/side set.

_________________
Richard
http://www.guitarmaker.com

Its on the inside ... heck I have fixed worse on the outside .. and they pretty much disappear. I had a similar crack on a set of mad rw .. right at a pin knot, right on the upper bout peak.. customer at the time decides he doesnt want to have me convert it to a florentine ... so I kept that set and got another ... then, later after building and finishing the cracked one, I cant find the fracture anymore and its on the outside, under high gloss. BTW .. customer eventually went for a florentine on the new set when he saw the shape I was planning on another ....

its coco ... CA it . Sand flush, move on with the next steps. Plus, you have the kerfing to glue over it as well.

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

Fix it!

I bent some wenge, and it did not crack cross grain, but along the grain due to the cold it was left in. I didn't throw it out til I found the 3rd crack and everyone startetd tellin me how bad wenge sucks.

Fix it.

For all of the reasons mentioned., and don't look back except to learn from where you've been.

My last build had almost exactly the same kind of crack in a set of Lacewood sides. I didn't think twice about repairing it. The instrument is fine and nobody has ever said a word because there is nothing for them to notice or to care about.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

I've broken binding in a similar fashion and had success with a CA repair, never broke a side ...YET!

I was told by a long time builder that "Every builder makes mistakes, what separates the "great" from the "good" is their ability to repair their mistakes so they are not detectable".

I always at least try to repair my mistakes, at least this way you're getting practice at hiding what would normally be a unrecoverable mistake for a "good" builder.

Yearn to be great!!!

Greg

On my first build (which is still my only build so take this for what it is worth) I took a big chunk out of the Koa (UKE) top when I was trimming it flush with the side. I thought I had ruined it and was going to replace it with a spruce top. Then I decided to try and fix it. I glued the chunk back in, sanded it down and you can hardly see it. I can find it, but I have to look. I have never had anyone mention it. In that I learned that I could fix mistakes.

That was a beautiful back and side set, it would be a shame to see it go to waste. I would fix it and build the rim. If you still are not happy with it then go ahead and order a new set. You will have learned on this rather nice practice set.

I still plan on using your set as a reference when I place my LMI order.

John

I broke a EIR binding completely in half while installing, and I just super glued as I installed the binding. No one can see the crack, it is completely gone. I suspect that will be case here too. This really is a no brainer. Glue and move on. Good luck!

_________________
Tracy
http://www.luthiersuppliers.com

The crack looked deeper last night. I could have sworn I saw a suggestion of a crease. Must have had one to many mudslides. Anyway a little tear out is not that bad. For some reason , though fixable, waist cracks bother me.


Said with due humility I am a hobby builder

_________________
"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

If the guitar is going to be your guitar, fix it and enjoy the guitar. If it's going to be sold to someone else,
throw that side away and get a new one. You'll regret giving a repaired side to a customer.

Never rely on spreaders or jacks to make a side fit your mold either. Bend it to fit the mold exactly. If it doesn't
fit, go back to the bending iron for a minute and make it right.

Regards,
Kevin Gallagher/Omega Guitars