I told you my soundpost was too tight...

[moles]

I had posted recently about looking for a luthier that could help me with soundpost fit and position, as well as asking him/her some questions about my fingerboard and endpin etc... Called a couple, but I'm jam packed for another couple of weeks so I figured I'd leave it for now and get things tweaked proberly when I can afford the time away from the bass.
In hindsight, that might not have been such a good plan.

While loading up for my evening of two rehearsals and a set-up and run through at the club I'm playing this weekend - I noticed the huge gaping crack in the back right at soundpost position.

When did this happen??!?!

Frantically called L&M, where I bought it. Technically it's missed the warranty by about a month, but it's so close that they're going to work with me on it. They're pretty good like that...
Sent me home with a rental for the weekend - nice enough bass, but it ain't mine, and I'm going to be struggling tonight with the different scale length and lack of pickup..etc etc..

Still - I'm not sure what the end result is going to be. It's a ply Strunal. I've read enough here to know the top is going to have to come off. Then what? Is a crack in such a high pressure area feasible to fix? Is the back going to have to be replaced? Is it worth fixing this kind of thing on a plywood bass?
Am I going to be kicking off the summer with a real expensive outdoor bonfire??

[farmerdude]

I dont know bout' the plywood "cracking" business ...but sounds like you will get a sound post patch. They may be able to do it without taking off the top??

[Gearhead43]

Yeah, how the hell did a ply bass crack THAT bad just because of a tight soundpost? In the ply bass world, Strunals are generally pretty well-made basses. Most plys come from the factory with the posts fit on the tight side, but what is really going on here?

[moles]

Well, yeah - I'm half joking about the tight soundpost being the culprit. But under normal circumstances (whatever they are) you would think this kind of wound would occur during - what, a fall from the back of a truck or something? It's been bumped around some since I've had it, but nothing serious. Or maybe I'm still green at this and don't know how fragile even a ply bass is? It's got some very obvious, much worse dings from previous users. A big chunk out of the scroll, and one on the right hand side rib near the top. To me this stuff is character, and (I thought) a good sign that the bass can take a little bit of bumping around and whatnot. The only thing I can conceive of is that it face-planted at some point in the past, but the damage was mild enough that it took this long for the tension to push through the crack -?
Either way, it's a rotten little surprise...
Who knows - maybe this'll be one of those situations in which the bass will sound better after it's repaired..
Fingers crossed.

[M Ramsey]

Originally Posted by moles

Well, yeah - I'm half joking about the tight soundpost being the culprit. But under normal circumstances (whatever they are) you would think this kind of wound would occur during - what, a fall from the back of a truck or something? It's been bumped around some since I've had it, but nothing serious. Or maybe I'm still green at this and don't know how fragile even a ply bass is? It's got some very obvious, much worse dings from previous users. A big chunk out of the scroll, and one on the right hand side rib near the top. To me this stuff is character, and (I thought) a good sign that the bass can take a little bit of bumping around and whatnot. The only thing I can conceive of is that it face-planted at some point in the past, but the damage was mild enough that it took this long for the tension to push through the crack -?
Either way, it's a rotten little surprise...
Who knows - maybe this'll be one of those situations in which the bass will sound better after it's repaired..
Fingers crossed.

Just curious. Have you been hauling this bass in a vehicle with the bass on it's back? Raod bumps and bass backs in vehicles are not a good combination, even with plywood basses. This may NOT be your case, but just trying to help you figure out how this happened.

[Damon Rondeau]

Bass luthier Jeff Bollbach has (used to have?) on his web site some compelling thoughts about the "tight soundpost" thing. If I'm remembering correctly, Jeff asks you to contemplate a normal, properly-fit soundpost under normal string tension. Imagine cutting a hand-sized hole in the rib of the bass next to the soundpost. Given the normal tension, you could reach in, grab the post and lift the bass up over your head and that post won't budge. Remember, under normal conditions it's sitting under hundreds of pounds of pressure. (Actually, probably not hundreds, huh? Anyone know how much of the overall tension is absorbed into a pressing-down-onto-the-table component?)

I'd bet the problem most likely wasn't a too-tight soundpost. I'd say one way or the other that bass got a whack. Maybe riding on its back in your vehicle, as Mike suggests. Could've been any other kind of mishap, who knows?

So, moles, I guess you're really looking for a bass luthier now, huh? I was thinking about this the other day and wondered if a guy like Bob Grierson -- local Lord and Master of all things slab, for DECADES now -- would have any ideas about who's around and who can do what with double basses?

[moles]

Yeah - I've read that bit on Jeff Bollach's site, and it makes sense to a degree anyway. I still wonder if there's something different about the way the pressure is distributed, even though perhaps the amount is similar in a well fit post vs too tight. Again though, I was just kidding around with the thread-title. I do that when I freak out about stuff. My ex-girlfriend didn't get it either.
If the post was too tight because someone tried to move it around themselves and wound up getting it stuck with the edge of the post pressing into the back (as opposed to straight) - I imagine that would multiply any stress placed on the back by tension, or bumps or whatnot. Am I right?
As for riding around in my vehicle - possible, but a bit of a stretch. It's usually not flat on its back, but half twisted to the left, so that it's supported by the rear right corner (the one that rests against my hip while I'm playing). I have a bit more room for other gear beside it that way, and I'm usually careful to not have it positioned directly on its side which would put it in danger of falling onto the bridge and, oh I don't know.....punch the soundpost through the back..? Right.
I suppose a cabinet may have slid into it at some point, who knows..
I still haven't heard anything from L&M. Called Friday - was told very little, but it sounds like the 'regular guy' was going to pick it up on Saturday.
Is is feasible to patch it without taking the top off?

[DaLong]

The only way that bass got that soundpost crack was from impact. Maybe when you were not looking, some one tipped it over. Good luck getting that fixed too. Of course the top is coming off and maybe you can patch it. The problem is that with plywood, they crack travels through the plys. You can't truly fix it. Thank goodness that they are putting it under warranty. A lot of times he cost to fix that is more than the cost of the instrument. Wood does not break on its own for no reason unless it is defective and plywood certainley doesn't do that.

[Jake deVilliers]

I don't mean to start an argument DaLong, but a guy brought a Seagull guitar into Long & McQuade last week for repair.

The plywood side had a crack right across the grain that was pinching his leg when he played! Very rare indeed, but it does seem to happen - must have been the two inner layers of the laminate having seams on top of each other.

I've seen cracks/splits in the outer veneer of Czech basses before too, right over the sound post. I think sound post patches are a good idea with a plywood bass.

[DaLong]

Originally Posted by Jake deVilliers

I don't mean to start an argument DaLong, but a guy brought a Seagull guitar into Long & McQuade last week for repair.

The plywood side had a crack right across the grain that was pinching his leg when he played! Very rare indeed, but it does seem to happen - must have been the two inner layers of the laminate having seams on top of each other.

I've seen cracks/splits in the outer veneer of Czech basses before too, right over the sound post. I think sound post patches are a good idea with a plywood bass.

I understand what you are saying, but the the cost of repair could be more than the bass is worth. To take the top off alone could be about 300 to 500 bucks, that before actually doing any work. Small cracks are ok. They can be taken care of. I had a bass come in that was a christopher plywood that a rockabilly bassist had jumped up and down on... The post was sticking about an inch out of the back. Maybe that was a soundpost hole not a crack. Either way it can be repaired, but you will have to pay out the nose to do it. but, tt all depends on how you look at it and your emotional attactment to the bass. (btw, watching someone take the top off your bass is like watching surgery on your best friend, its sickening.)

[1st Bass]

Yep, and frequently such a "soundpost crack" in a plywood bass can be repaired without opening the bass. Depends on how severe it is. I repaired one a couple of years ago, using the method Chuck Traeger teaches in his book, and it worked very well. It was a little scary, as I had never tried such a thing, but in the end, they had a closed, glued crack on the outside, and a round patch on the inside, about 75 mm across, if I remember right, and about 5 mm thick in the middle, tapering to 2mm around the edges.

I had first built a rather cumbersome frame in which to imprison the bass, so as to be able to put pressure only where I wanted it from the outside. I glued the crack, and used that frame to press the back and allow the crack to fully close.

Then, I made a "screw-jack" of a large turnbuckle, and inserted it through the f-hole, and adjusted it to where it was about right to hold the patch. I inserted the glue-coated patch onto the glue-coated location where it belonged, then used a short soundpost to hold it while I got the jack in place-- I turned the jack a couple of threads, and let the whole thing dry. Probably the soundpost would have been sufficient, but I was afraid the whole thing would shift under pressure. I wish I had had a small pneumatic cylinder with which to achieve my clamping pressure.

At any rate, it worked, the school it belongs to is happy, and the crack has neither migrated nor reappeared. Chuck would be proud...

[Jake deVilliers]

Nice work Chet.

That's more or less how I would approach Moles' repair except for the turnbuckle. Its easier for me to put a stick inside and then just clamp from the outside, right over the whole assembly.

Also keeps you from pushing the top off with the internal pressure!

[1st Bass]

Well, yeah-- that is why I had the "cumbersome frame" I mentioned-- I didn't have any clamps that were big enough to reach around the bass, so I made a large rectangle of lumber, and drilled to place large carriage bolts in strategic locations, so as to put pressure exactly where I wanted it (like a clamp). Clumsy, but effective.

[Jake deVilliers]

Ah. I didn't get that bit at first. My apologies.

[1st Bass]

Did you make the clamp you use? That must be one monster clamp. I s'pose I could fabricate something like that out of aluminum, but I had the lumber, so that was free-- just had to buy the carriage bolts.