Double Bass Replacing an endpin block?!

[eh_train]

Hi TBers,

This is addressed particularly to luthiers, or luthiery-minded bassists...

I have acquired yet another distressed plywood bass that I am determined to repair. It's labelled as an 'Anton Schuster' and is about 50 years old, and made in Germany. Among the positives, it has a very nice scroll and an undamaged neck.

Among the bad stuff, the neck is unfortunately off the body right now (due to a fall). Worse, and the reason for the post, is that the endpin block has come loose. As a result, the ribs around the endpin have started to separate and distort. I think that the distortion isn't so bad - yet - that they can't be steamed back into shape.

I have taken the top off, and the attached pic. shows the damaged block. [Note, the shards of wood to the right of the block are part of the top - since reattached!]

It seems like the install of the original block was a very quick and dirty job. In most instances, isn't the block a wider piece of wood, usually with a nice arc shape to the top portion?

Anyway, my questions are: Where do I obtain appropriate wood for the block (e.g., what type of wood, and how old and how dry does it need to be)? Any suggestions as to whether I should try to straighten the ribs first, or shape and install the new block, then worry about the ribs? Maybe I need to do both simultaneously??

Any help is greatly appreciated!

Paul
(Eh_train)

 

[eh_train]

Hi all,

No response to my many questions, so I'll try just one: Am I correct in thinking that the original block (see pic.) looks extremely flimsy? Note, it's actually less wide than the saddle!

Chandler's book recommends Pine for the blocks. I'm still curious, however, as to whether it needs to be particularly dry, or aged, or what have you...

Anyone out there done this??

Thanks,

Paul (Eh_train)

 

[Jake deVilliers]

That looks about average.

Are you sure you need to replace it?
If you really need to replace it, the older and drier the the better, within reason.

I'll try to attach a picture of a Kay end block; its what I have a picture of.

Jake

 

[PoorPlayer]

I have never seen an open bass first-hand. Check Matthew Tucker's build and see what his looks like.

Upton Bass' workshop shows some pictures of open basses you could look at for comparison.

Ken Smith has pictures of an open [Invalid or Expired Link Removed] where you can see the tail block.

 

[Matthew Tucker]

To me, it looks like its not the block that has failed but the plys it was stuck to. What happens with old plywood is that the glue gets brittle and the layers delaminate. Then there's nothing for the block to hold onto. I think that's going to be what you have to repair solidly. Then just glue the block back on. The block isn't split, is it?

 

[eh_train]

Thanks all!

I have done a similar repair on a Kay bass, although in that case the ply ribs had separated cleanly from the block. Jake, thanks for your pic. It still seems to me that the block in my Kay - a 1940 - was a little wider...

Matthew, you're quite right that the real problem is the separation of the plys. I will try to get the block out without too much further damage (unfortunately it's still nicely glued to the back), then see how best to reglue/repair the rib plys.

Cheers,

Paul

 

[Jake deVilliers]

The block in the picture is a 1950 Kay.

Why do you need to pull the block off the back? Could you just align the ribs and glue the whole thing back together using the end block as the inner caul? I mean, its hard to tell what's going on from the one-dimensional photo, but are you complicating things?

Seeya, Jake

 

[mpm]

Also, sometimes the small shards of wood that pulled off the opposite surface help in the alignment of both surfaces.

 

[eh_train]

Jake/MPM,

I have looked at it again, and the whole business *might* go back together neatly. I sometimes run into trouble when there are little loose bits that almost fit back together. If they get out of alignment then they act as the "fly in the ointment", and very effectively keep the parts from going back as they should. I suppose if there are such odd bits, I should take them out altogether, rather than risk a poor fit??

Also - and I hope this isn't a can of worms I'm opening - I'd be more comfortable doing this with carpenter's glue than with hide glue. Whenever I use hide glue, I'm always leary of getting it together quickly! With carpenter's glue there's more time to ensure the correct fit...

Faced with a similar repair (remember it's an inexpensive ply bass), would others tend to worry about "reversability", or just go for efficiency??

Thanks for any further thoughts!

Paul

 

[Jake deVilliers]

I would have no problem with you using LePage's yellow for that repair. The joint has also been contaminated with who knows what kind of glue.

It is possible to take apart basic yellow; just don't use something like Titebond III!

You're making a permanent repair anyway, not a serviceable joint.

Git 'em Paul.

 

[Matthew Tucker]

So, what you going to glue the neck back in with??

I'd use something permanent for the repair to the ply (like epoxy), if you don't repair the ply first, no amount of yellow glue will stop it coming apart again. The endblock takes more wear than the rest of the bass, every time you stand it upright. If the plys aren't stuck together permanently, they'll work apart again.

That's what I think.

Go on, use hide glue for the block. You'll need practice anyway for when you do the neck!!!!!!!!

Clean all the old **** off the block. check your dry clamping setup first and make sure you have a close fit between clean surfaces. Warm the block and the ribs with a hair drier. Use nice fresh hot glue. prime the surfaces thinly - doesn't matter if the glue gels a bit. Then, quickly slop in more hot hide glue, the hot glue will remelt the primed surfaces. Then clamp like mad. Run a bolt and wingnut through the endpin hole too, that'll keep the thing in position.

That's what I'd do.

 

[bassist1962]

I have a carved German shop instrument that the end block is twisted, loose, or detatched in some way. I know that I am going to get a lot of 'take it in and see what the luthier says' replies, but the nearest on is 50 miles from me, so I would appreciate an estimate of cost - worse case scenerio, if possible, before I take it.