Double Bass Double Bass snapped at the heel

[EAME]

Yes,me too UnbrokenC...It will Be good to get new strings and play again.
I've got both the glues,just waiting on the thread bar now.

Lag bolt is playing me up tho.

Ideally :

1.25 Shank [1 1/4"]
2.5 Srew [2 1/2"]

= 3 3/4 Inch total length [ 6mm ]


HEX HEAD LANDSCAPE SCREWS SLEEPER DECKING FIXING TIMBERFIX / TIMBERLOK / IN-DEX

This at 6.7 diam and 87mm length,with it being countersunk is the nearest I can find.Is this good to go?
I have to buy two packs on ebay,but local hardware ask me to buy big pack at twice as much,so ebay it is.

Is 100mm [just under 4"] going too far into the 6.5" Heel.??

 

[Ortsom]

In post #54 we were considering 2.5" total length for the central one, and 3.5" for the two top ones. Metric that is 63.5mm for the central one, and 89mm for the top two. The closest he has are 60mm & 87mm, but considering that here you need to countersink the head, those would be fine. Or take 3 of 87mm.

At 6.7mm OD these are a bit bigger though, but that should be OK. You'll have to judge for yourself how big the holes would be, properly scaled on the heel.

100mm long seems a bit pointless to me. You should not replace all the wood by steel, just repair the broken section.

Can you drill the holes?

 

[robobass]

I don't see the need for such thick screws. I'd choose something like a #8 drywall screw, 1.5" or 2" length.

 

[robobass]

I don't see the need for such thick screws. I'd choose something like a #8 drywall screw, 1.5" or 2" length.

Edit: That would be plenty strong, and you would remove a lot less wood!

 

[EAME]

Edit: That would be plenty strong, and you would remove a lot less wood!

Are you talking screw length or total RoboB?

 

[EAME]

Are you talking screw length or total RoboB?

Ye,good point about removing less wood.

 

[EAME]

Ye,good point about removing less wood.

Sorry,didn't see #8..

 

[EAME]

Can you drill the holes?

Yes I can do the drilling Ortsom,shouldn't be a prob

 

[EAME]

#8

Just a normal screw?
I think the lag screw's got to be a better idea,countersunk..


M5 (5mm) A2 STAINLESS COACH SCREW HEX HEXAGON HEAD WOOD SCREWS LAG BOLT DIN571


Right:This has got to be it.
All agreed?..
[good price also]

 

[Ortsom]

Eame, your focus on democratic selection is admirable, but I find it difficult to sit here behind my PC and shout enthusiastically 'yeah that's the one!'. I'm much better at choosing when I have the screw in front of me, as well as the thing they have to go into. What I'm trying to say is: as courageous fixer of broken things & fearless wielder of blunt instruments just choose something that makes sense to you.

That said, 6.7mm OD is indeed a bit firm, and with the neck part being 1.75" thick, a 1.5" tall screw is too short.

The longest he has in the advert you now linked to is 60mm, which would be roughly OK for the assembly screw, if countersunk, but short for the two top ones. Mind you: these latest are non tapping, the previous ones you showed were self tapping (which is desirable in this kind of wood).

PS.: look at the tip of the screw to see the difference. If they have a sharp wedge ground-out, they cut thread into the wood, if not they push the (sharp) thread into the wood, at the risk if splitting it.

 

[robobass]

I haven't been paying close enough attention to calculate the proper screw length, but I think 1" after the break would be a good target. I agree that the unthreaded shaft on a lag screw might be desirable, but I use simple drywall screws because they are thin and have a coarse and deep thread. As far as tapping screws go, they might be advantageous, but drilling the proper diameter pilot holes is more important. I usually test a pilot hole on a piece of similar scrap wood before committing to final drill size. Here, I would clamp the joint together as well as possible, and drill the pilot hole through the entire projected screw length. Then disassemble the joint, and VERY carefully bore out the neck portion of the holes to accommodate the screw diameter. Epoxy in the holes could cause a splitting problem, but I would apply it sparingly and try to keep it out of the holes.

 

[EAME]

Yes,me too UnbrokenC...It will Be good to get new strings and play again.
I've got both the glues,just waiting on the thread bar now.

Lag bolt is playing me up tho.

Ideally :

1.25 Shank [1 1/4"]
2.5 Srew [2 1/2"]

= 3 3/4 Inch total length [ 6mm ]


HEX HEAD LANDSCAPE SCREWS SLEEPER DECKING FIXING TIMBERFIX / TIMBERLOK / IN-DEX

This at 6.7 diam and 87mm length,with it being countersunk is the nearest I can find.Is this good to go?
I have to buy two packs on ebay,but local hardware ask me to buy big pack at twice as much,so ebay it is.

Is 100mm [just under 4"] going too far into the 6.5" Heel.??

Eame, your focus on democratic selection is admirable, but I find it difficult to sit here behind my PC and shout enthusiastically 'yeah that's the one!'. I'm much better at choosing when I have the screw in front of me, as well as the thing they have to go into. What I'm trying to say is: as courageous fixer of broken things & fearless wielder of blunt instruments just choose something that makes sense to you.

That said, 6.7mm OD is indeed a bit firm, and with the neck part being 1.75" thick, a 1.5" tall screw is too short.

The longest he has in the advert you now linked to is 60mm, which would be roughly OK for the assembly screw, if countersunk, but short for the two top ones. Mind you: these latest are non tapping, the previous ones you showed were self tapping (which is desirable in this kind of wood).

PS.: look at the tip of the screw to see the difference. If they have a sharp wedge ground-out, they cut thread into the wood, if not they push the (sharp) thread into the wood, at the risk if splitting it.

short for the two top ones

Don't forget , the two top ones are the Thread Bar.
Yes,I cant believe I'm dithering over a bloody screw!
The size in one but not the other,and of course I'd rather have them in front of me for sure.
Good point about self tapping...

 

[EAME]

Invalid Link Removed

Got this one,I'm pleased to say.
I measured the screws in the pic [I know it is a guide only.apparently] but they do seem to measure up in real scale,and the 75mm [ just edited this,I put 87mm?!] has the 1 1/4 shank that is ideal.I'll just have to go steady:
That neck is going nowhere ....

 

[EAME]

So sorry,been off line with a bad comp crash until now..
For anyone still interesested in this fixit experiment,I am now forced to concede that it is probably a bad idea going with the screw size I chose,and,now I have one here,it does look good but,as you've rightly pointed out,it would remove far too much of the wood for my liking,the point being is to leave as much as possible,and could quite easily cause some splitting if not done really well.
I have glued those chips in as well as I could,not being able to clamp them.
I am still waiting for the Thread to turn up,and so gives me time to find something like a 4.5 Lag instead of this 6.7 one...
I'll get there in the end......

A good progress made today and I found a 6mm [instead of the 6.7mm] and the hole is well cut,touch wood [sorry],there will hopefully be no splitting.There's no rush,I'll have me a Scotch and take it steady!
By the way,the neck sat in there sweet,almost no need to clamp,nice n tight.
Just got a slight downward angle,all I need now is the Thread to turn up and then the work really begins.
I'm confident with the angle as well,so I'm going to use the Flight Case as my guide to help set her up again.
Back soon.

No dont forget I glued the chips on the neck instead Ortsom,and yes they didnt go back on very well as Id of liked but they're syuck on as best as I could as clamping them was a problem without them slipping outward..
Here's the bar holes cut [no splitting so far and good room for the glue,not overly sloppy,so it should take gluing without splitting.
I just got on with it today to be honest.No amount ummin n rring will ever get it done,so here's today's effort..









































So I glue the threads into the Heel next.
I can do this with the Hide glue cant I?
Then when that's set or near set,I then glue and screw the neck down and position the blocks and get the angle sorted in the time before it set's for good and tightened up.
Then I glue the Fingerboard back on.
I think that's what we said .

 

[Ortsom]

Very good, ta for the update!

If your first pic above shows the chips glued in place, that looks pretty sound, in the sense that I can't see any glue lines.

I think it also shows why it broke the way it did: the 'mirrors' in the wood along the break suggest the quarter-cut face is pointing right up, along the break. That is the normal way for wood to split, and for better strength the wood should have been rotated 90° (so quarter face pointing sidewards, rather than upwards). A consequence of a cheap neck. But the idea is that the long reinforcement bars (inserted after glueing the neck back on) will take the load & prevent future splits.

Good fit or not, I still suggest verifying the alignment prior to glueing & before the glue sets. Then have a scotch while the glue sets.

 

[iiipopes]

[Sigh] A couple of months ago, my heel cracked. I took it to the the local luthier who works on school orchestra instruments. One look, and he said it was an internal grain flaw, wouldn't touch it, and sent me to the nearest major city dedicated bass shop. Before driving up, I called, sent pix. They said they wouldn't touch it until it broke completely.

Now, I am faced with playing it until it does break completely (as we all know - Murphy's law - it would probably happen in the middle of a gig), or alternatively using something like a really small needle and syringe to inject hide glue deep into the crack and clamp it to try to stabilize it, so I don't end up as a horror story or a botch story. Worst case scenario: it breaks completely, a hidden internal flaw or knot lets go, and I have to get either a new neck or a new bass. Since it was a CCBSO which I purchased inexpensively on purpose and set up myself to learn how everything works, I wouldn't be too disappointed if it disintegrated, because it has definitely earned its keep over the last few years, and an upgrade to a boutique ply bass would be nice.

That said, I would rather try to inexpensively fix it by injecting hide glue and clamping it to see what it does before spending the $$$ on another bass, as the setup is exactly to my personal ergonomics: mensure, scoop, etc., and I would hate to have to start all over from scratch. We'll see what happens going forward.

Hmm - install a set of starks to hasten its demise? At least that would finish opening up the crack so a luthier could actually see if it is worth repairing. In any event, as with my tuba, sousaphone, and electric basses, about which I am on a first-name basis with the respective techs and luthiers which keep them maintained for me on issues beyond straightforward maintenance and setups, I will keep in mind the Harry Callahan quote: "A man has got to know his limitations."

Right now I have essentially Bels with a Spiro 3885,5W E string to get old-school swing band thump which are overall half-way in tension between S42 Weichs and S42 Mitts. That gig has now ended. Go with S42 Weichs to ease the tension and make it last as long as possible?

[Not so tongue-in-cheek for the next comment] And also, keep bringing the pork chop to gigs with foam under the strings at its bridge so if the heel does let go, I can at least finish the gig....

[Completely tongue-in-cheek quote] Or take a rubber mallet and finish separating it with [either the Pink Floyd background comment or the Mikado Pooh-bah line, depending on your music background] one short, sharp, shock?

Any ideas would be welcome, as right now I am in a no-man's land with a crack literally staring me in the face as I play, dreading the next gig instead of looking forward to it.

 

[EAME]

Very good, ta for the update!

If your first pic above shows the chips glued in place, that looks pretty sound, in the sense that I can't see any glue lines.

I think it also shows why it broke the way it did: the 'mirrors' in the wood along the break suggest the quarter-cut face is pointing right up, along the break. That is the normal way for wood to split, and for better strength the wood should have been rotated 90° (so quarter face pointing sidewards, rather than upwards). A consequence of a cheap neck. But the idea is that the long reinforcement bars (inserted after glueing the neck back on) will take the load & prevent future splits.

Good fit or not, I still suggest verifying the alignment prior to glueing & before the glue sets. Then have a scotch while the glue sets.

That sounds like the best order of play,will do hh.

[Sigh] A couple of months ago, my heel cracked. I took it to the the local luthier who works on school orchestra instruments. One look, and he said it was an internal grain flaw, wouldn't touch it, and sent me to the nearest major city dedicated bass shop. Before driving up, I called, sent pix. They said they wouldn't touch it until it broke completely.

Now, I am faced with playing it until it does break completely (as we all know - Murphy's law - it would probably happen in the middle of a gig), or alternatively using something like a really small needle and syringe to inject hide glue deep into the crack and clamp it to try to stabilize it, so I don't end up as a horror story or a botch story. Worst case scenario: it breaks completely, a hidden internal flaw or knot lets go, and I have to get either a new neck or a new bass. Since it was a CCBSO which I purchased inexpensively on purpose and set up myself to learn how everything works, I wouldn't be too disappointed if it disintegrated, because it has definitely earned its keep over the last few years, and an upgrade to a boutique ply bass would be nice.

That said, I would rather try to inexpensively fix it by injecting hide glue and clamping it to see what it does before spending the $$$ on another bass, as the setup is exactly to my personal ergonomics: mensure, scoop, etc., and I would hate to have to start all over from scratch. We'll see what happens going forward.

Hmm - install a set of starks to hasten its demise? At least that would finish opening up the crack so a luthier could actually see if it is worth repairing. In any event, as with my tuba, sousaphone, and electric basses, about which I am on a first-name basis with the respective techs and luthiers which keep them maintained for me on issues beyond straightforward maintenance and setups, I will keep in mind the Harry Callahan quote: "A man has got to know his limitations."

Right now I have essentially Bels with a Spiro 3885,5W E string to get old-school swing band thump which are overall half-way in tension between S42 Weichs and S42 Mitts. That gig has now ended. Go with S42 Weichs to ease the tension and make it last as long as possible?

[Not so tongue-in-cheek for the next comment] And also, keep bringing the pork chop to gigs with foam under the strings at its bridge so if the heel does let go, I can at least finish the gig....

[Completely tongue-in-cheek quote] Or take a rubber mallet and finish separating it with [either the Pink Floyd background comment or the Mikado Pooh-bah line, depending on your music background] one short, sharp, shock?

Any ideas would be welcome, as right now I am in a no-man's land with a crack literally staring me in the face as I play, dreading the next gig instead of looking forward to it.

 

[EAME]

That sounds like the best order of play,will do hh.

Any ideas would be welcome, as right now I am in a no-man's land with a crack literally staring me in the face as I play, dreading the next gig instead of looking forward to it

I think that must be worse,you know,waiting....
But if it can be injected,why not try that anyway?...Mr Waters could be right,but as long as the 'Oh no *** have I done' face
doesn't get in and haunt your mind,try anything,but the Bass people in here will help you decide,far better than I can advise:
I made a terrible job of attempting a repair on this one originally,thinking I could just glue the bloody neck back on with something that apparently has the strenght of ten thousand horses [or something] but is absolutely useless at holding two pieces of wood together under tension....
If this actually WORKS [not the method,just my ability to implement it] then [I will have to buy Weiss strings for evermore..hh!] I will be well and truly big'd up about it,as I haven't got a clue what I'm doing!!
I like this forum for the advise it gives,about anything to do with 'Bass',by some knowledgeable people:
You are bound to get an answer that sits well with you.
I'm still wondering what you mean by still being able to play with foam under the Bridge tho?

 

[EAME]

AAARGH..!
The wood is screaming..
I hope somewhere in the world this did not replicate in flesh and blood,but,it probably did..
I'll be glad to get this unsettling face all covered up.....Voodoo Hoodo n' all that..

 

[EAME]

AAARGH..!
The wood is screaming..
I hope somewhere in the world this did not replicate in flesh and blood,but,it probably did..
I'll be glad to get this unsettling face all covered up.....Voodoo Hoodo n' all that..

Only one thing for it:
will have to make it a 'smiley' before I'm done:
Unintentional Voodoo, for happy people.