An Oddity...old bass refurb

[Andyjr1515]

This is a bit of an oddity.

So much so that true luthiers should look away now.  And to the general readers...DON'T TRY THIS AT HOME - the techniques and methods demonstrated in this thread have been undertaken by an inexpert who has spent years gaining no skills and expertise and therefore has a complete and imperfect knowledge of what he is dealing with.  The techniques on view are not conventional and should not be attempted by anyone who has the slightest amount of common sense or sensitivity to fellow builders or modifiers of instruments.  

I was contacted a few weeks ago by a guy I did some small stuff for last year.  He'd bought an old 'project' bass (70's/80's) on fleabay and it turned out to be in even worse condition than he'd suspected.  "Now who would be daft enough to take this on?", he thought ",....Oh yeah....that crazy guy who made that bass out of african balsawood...Wonder if he's been let out of the institution yet...."

Was I happy to take a look?

Of course

Now when it arrived.....wow.

At first sight it looked OK.  A bit Alembic Stanley Clarke (although emphatically NOT an Alembic)...definitely a bass of its time...not my kind of thing but quite characterful:

 

Now - you may have noticed the little dark line between the middle neck splice and its neighbour...

...the through-crack looking dark line:

...and the 'go crazy with a blunt forstner bit' chamber

 

 

...and the 'just go crazy - why waste energy putting a bit into your press drill....let's try a rusty nail instead' control chamber rout:

 

Oh...yes...and about those body laminations...why use glue when you can use old marshmallows?:

 

This isn't the stripping commencing - this is finding out how deep that crack is ( and that's a 9" palette knife!):

 

So, Andy.  Fancy tackling this, then?

 

Too b****y right Andy does!!!! 

[ScottR]

I was looking at the first two pics thinking are those chambers really as bad as they look? Nope-- much worse.

I'd guess that has seen use as a canoe paddle.

And I can just see you rubbing your hands together and cackling with glee as you get set to sink your teeth into another fun project.

SR

[SIMpleONe89]

Dayum! And I thought my control cavities look shoddy! 

Looking forward to seeing how you turn this around Andy!

[Chuck_Chill-Out]

Yep, I have a need to follow this adventure. 

[djobson101]

Nice 

[Andyjr1515]

As you can imagine, I spent a lot of time just looking at this...and measuring...and thinking...and sticking things into various bits of it....and bending things...and re-measuring.

First of all, the woods.

Neck:

• Oak centre (yes - quite!)
• then maple (maybe)
• then mahogany
• then at the headstock more maple (maybe)
• then a darker mahogany-type of wood

Body:

• Ash top
• then mahogany
• then maple (maybe)
• then mahogany
• then OAK!!!  Cross-grained!!!!!!

Other observations included:

• Catastrophic failure of a number of the glue joints - probably due to water or dampness damage
• It must be therefore assumed that ALL the joints are suspect
• Had it been re-glued in the past?  At first it looked like it had...now I wasn't not so sure
• The fretboard was clearly ebony but appeared to be a bit sine-wave shape.  The frets looked like they have been levelled with a used house-brick

My conclusions and good intentions (during the time I was still attempting to be correct and proper in my luthierial approach) were to:

Take it all to bits, clean it up and rebuild it part by part.

As you will soon see....so much for good intentions...

 

 

[djobson101]

22 hours ago, Andyjr1515 said:

As you will soon see....so much for good intentions...

 

 

I'd say your intentions are better than the old auspice of "saving on wood glue by upcycling stale marshmallows"  

[curtisa]

You say refurb. I say rebuild. You've certainly got your hands full with this one.

[Andyjr1515]

3 hours ago, curtisa said:

You say refurb. I say rebuild. You've certainly got your hands full with this one.

Yes - in fact, it won't be much different in the end to a full build....

[Andyjr1515]

18 hours ago, djobson101 said:

I'd say your intentions are better than the old auspice of "saving on wood glue by upcycling stale marshmallows"  

I've go to say, stale marshmallows work just fine on many of my builds but, like all things, it's all about practice and technique.  And expectation.  

Hmmmmm....maybe I could do another 'Bedroom Builder' tutorial on the topic 

[Andyjr1515]

So - to taking it all apart.

Let's start with the panel that is already 80% off (and I exaggerate not).  That'll come off easily.

Here's the palette knife:

 

and here's how far it goes in:

 

Easy - a bit of steam will have that off in minutes...

 

....four hours later (FOUR HOURS!!!!) after trying:

• steam
• hot palette knife
• very hot thin scraper
• medium japanese saw
• huge japanese saw
• hammer
• chisel
• I even got this far and I STILL couldn't get it off:

 

but eventually....it came off.

You can see the small areas that were stuck by the lighter patches on the mahogany.

 

With reference to the 'take it all apart and rebuild it' master plan....clearly in need of a rethink!

 

 

[ScottR]

What's that big two handled sheet metal thing you've got stuck in there?

SR

[Andyjr1515]

It's the flexi stainless steel sheet I use with the bending iron for the acoustic.  Keeps the steam in and is said to reduce splitting...

[ScottR]

Ah. I thought it was something like those old two man lumber saws.......for king sized bread maybe.

SR

[Prostheta]

Wow.

Words fail me.

[Andyjr1515]

17 hours ago, Prostheta said:

Wow.

Words fail me.

  Words that didn't contain some ripe anglo-saxon expletives failed me, too, at about 3 1/2 hours in!     

[Andyjr1515]

So the change of plan was this:

• Doing it the 'proper' way was simply not going to work.  ie Send it back from whence it came or attack it to try to pull it apart with almost certain bonfire material at the end of it
• Or onto the pragmatic - with the unknown glue potentially ready to catastrophically fail anywhere and everywhere else, a bit like with 'Tom's African Fretless' build, could it be established that at least the neck was strong enough and sound enough?  And if it was, then simply secure all the rest of the exploding components as best as they could be.

I discussed it fully with Mick, the new proud owner, and he agreed.  Let's go for it   

He also brought me up to date with things he would like incorporating into the build...   Based on the well known formula that "near-impossible challenges = extreme excitement", I became very excited indeed  

But first, was it going to be strong enough....

[KnightroExpress]

Your projects are great fun to watch! I can't wait to see what happens next....

[Andyjr1515]

The start of the empirical and pragmatic approach (because common sense and theory says this bass is going to fall to pieces) meant fitting a bridge, some tuners and some strings and putting real-life tension on to see what happened.

Mick, the owner, was ahead of me an already had sent his preferred hardware (that triggered a few more challenges, more of which later).

Aware that the zero-angled neck would probably mean a heavily recessed bridge, Mick's preference was to fit a tune-o-matic and stoptail.

At this stage, I would only need to drill for the stoptail.  But before I did that, I HAD to stabilise the extremely long (from the tailstock up to the heel) parting of one of the neck laminations) because the two sides of the body were wobbling about everytime I touched it!

Not a great way of doing it, but I flossed the joint as best I could (yes, that sandpaper goes right through:

 

Then swamped it with Titebond Extend and clamped the life out of it.  The crack didn't seem to extend beyond the heel, but I will be drilling into the heel and gluing a stabilising dowel in there before I'm done.

I also put the levelling beam on to flatten out the significant set bow, so that I could assess the relief and the effectiveness of the trussrod.  Some of the frets were sanded down to almost nothing but they were all going to have to come out anyway.

Then the stoptail bushes holes drilled, tuners fitted, bridge placed in a representative position, strings put on and tightened up:

 

It was tuned up, left overnight and then checked.  Conclusions were:

• It held tune (really!)
• The neck stood up to a fair bit of manual attempts at bending and distorting with no cracks, failures or tuning variation
• The relief was OK.  Interestingly, the neck seemed very, very stiff and relief didn't change at all with progressive tightening of the truss rod (that, otherwise, seemed to be behaving itself) and nor when the stings were slackened or tightened!
• The acoustic tone and volume was pretty impressive

Hmmm....

 

 

[Prostheta]

Well, it could have been a lot worse. It did seem to try and be a lot worse, let's face it.

[Andyjr1515]

1 hour ago, Prostheta said:

Well, it could have been a lot worse. It did seem to try and be a lot worse, let's face it.

Still might be....

as the old joke goes, 'Praise the Lord for it could be worse.  So I did praise the Lord and it did get worse...'

[Andyjr1515]

Having concluded that it was going to be a case of flossing, swamping and clamping, I set about cleaning up some of the other joints and re-gluing in situ.

The second back panel was only about 20% parted so I set about that one first.

One of the unusual features of the build that the back panels were oak....and cross-grained.  I managed to get the captive one re-glued:

It was glued SO well, and clamped SO tightly, this critter wasn't EVER coming off again.

I did the same with a split on one of the mahogany layers.

I then set about regluing the removed back panel after cleaning it up and re-flattening it

But this was odd - it had shrunk quite a bit - in TWO DAYS!!!:

 

Still drying and shrinking maybe.  

 

But, hang on....it's also got WIDER in the same time:

So clearly, whatever stresses and strains had pulled the bass apart in the first place, were still pulling it apart!

 

So back - once again - to the drawing board.

The oak cross grain panels were going to have to go.

Oh...remember the "this critter ain't never coming off" pledge? 

 

[Prostheta]

The whole problem here is the grain running 90°. If you look at the comparative expansion/contraction percentages of woods, there's a huge bias towards tangential shrinkage, closely followed by radial. That Oak is clearly on the quarter because the medullary ray flecks are visible. That means you've had huge shrinkage radially (IIRC, perpendicular to the growth rings).

Cross grain glueups never work. I've done a number of breadboarded table ends, and because of the huge difference between longitudinal vs. radial and tangential they need to be fit with work with the movement. That simply won't happen here.

How many years did it manage to stay in "one piece" before it started to rip itself to bits? You simply will not be able to keep this one in check. Time to source a bit of white Oak, methinks....

[Andyjr1515]

2 minutes ago, Prostheta said:

How many years did it manage to stay in "one piece" before it started to rip itself to bits? You simply will not be able to keep this one in check. Time to source a bit of white Oak, methinks....

....or WALNUT perhaps 

[ScottR]

The walnut is a good call. Now the back will look like a squinty eyed dude with a Fu Manchu.

SR