TheGreek's Mystery Bass Rebuild

[Andyjr1515]

No sooner has the varnish started drying on the Dreadnought Acoustic (other instruments) when another project has already got me engaged and excited

I got a PM from Mick (TheGreek) last week. He'd recently got hold of a really old bass that - when he received it - he realised was in need of major surgery. But it wasn't straightforward. And it didn't look easy. And it might not be possible. So was I interested?

Of course, I was interested

It arrived yesterday, a day before we leave for a long weekend at our daughters in very cold Aberdeen. Useful - it will give me something to ponder about while I'm (hopefully) huddled for warmth over a glass of one of my son-in-law's whiskies.

Because this is a [size=5]Granddaddy [size=4]of a challenge[/size][/size]

The bass has a strong hint of Alembic about it, but for reasons I'll go through later, I think it is an early 'in the style of' build. And, there's no way of putting this subtly, it is falling to pieces.

Here's the good:






...and here's just [i]some [/i]of the bad:





(yes - that's the other side)



This crack shows clear daylight all the way to the heel. It is only the fretboard that is holding some of the neck laminations together....




I was interested just how deep the cracks were on the wings laminations, so I got a spatula out of the kitchen.

Now you see it:


...and now you don't:



There's more...but this is more than enough to help me while away a few hours if the conversation dries up at my daughter's house.

The big ponder is this:[list]
[*]There is clearly a catastophic failure all over the place of the glue
[*]BUT - it does seem to be firmly glued in places
[*]The right thing would be to take it entirely down to the constituent pieces, clean it all up and rebuild from scratch
[*]But I might not be able to without splitting the wood in unpredictable and random places
[/list]
That should get me from Derby to at least Glasgow...and maybe Dundee... without having to make strained conversation with MrsAndyjr1515...

Andy

Edited April 20, 2016 by Andyjr1515

[scojack]

It's always cauld in Aberdeen .. take yer thermals Andy!
You have your work cut out there m8 looks like water damage to me ..good luck !
Ian

[Andyjr1515]

[quote name='scojack' timestamp='1461166854' post='3032101']
You have your work cut out there m8 looks like water damage to me ..good luck !
Ian
[/quote]
Yes - I think so too. Probably sat in a damp shed for years...

[TheGreek]

When I first saw this on eBay the photos didn't show the extent of the damage but I loved the look of it - that Alembic-esque-ness - that I couldn't resist. To me it's a bass that has had (at least) two lives. Whoever built it originally knew what they were doing - you can see that in the quality of some of the work. I believe that in it's second life whoever did the work on the pick up cavity/reglue was "[i]less skilled[/i]", let's say.

Andy had done some great work on a previous project I'd sent him and I'd religiously followed the build on Kert's singlecut bass (what a beauty that turned out to be) so I have absolute confidence that Andy will work his magic on this and bring it back to life and into the 21st century. Plans include the use of Sims Super Quad p/ups and gold (most probably) hardwear.

The big problem for me is that I'm going to have to follow this thread from behind a computer screen. I'm now facing the prospect of being the proverbial "[i]kid on Xmas Eve[/i]" for the foreseeable. For somebody who's used to "[i]instant gratification[/i]" and impulse buying this is going to be difficult...to say the least!

Looking forward to watching the build progress and, most of all, getting it back!! Can't wait!!!

[Norris]

If anybody can fix it Andy can. (No pressure! )

I'm looking forward to this one

[gary mac]

Really looking forward to seeing this one brought back to life.

[roman_sub]

Wonderful new project. I think this has potential to become quite a looker.

[TheGreek]

Andy and I were chatting about what it's made of. I think the darker woods some sort of Mahogany. Not sure about any of the other timber used. Suggestions??

[Norris]

The top and back laminates almost look like oak. Is the centre neck laminate walnut? Not easy to tell on my mobile phone with my knackered old eyes

[Andyjr1515]

I'm not entirely sure, but I'm thinking the neck is an oak middle, then maple, then mahogany. At the headstock, there is an extra slice of maple and what looks like mahogany, but is a different shade to the main splice, so might be a different wood altogether.

The body middle I reckon is maple, then mahogany either side, but I wonder if the top and bottom splices might be ash. It certainly looks like ash at the top. At the bottom, it's the same wood but there are birds eye-like blips and it has been laid on cross grain...and that looks less like ash to me.

And just to finish the materials analysis, the fretboard is ebony, and the glue is absolutely genuine 1970's Golden Shred Marmalade...

Edited April 22, 2016 by Andyjr1515

[Manton Customs]

With the grain orientated like that on the back it'd definitely cause issues like seam separation if given half a chance (such as damp conditions). I'd probably replace the back if possible for that reason, as it could happen again!

Your guesses on the wood species sound about right to me . Definitely looks like an Ash top with Mahogany and Maple. The back could also be Ash, but it appears to have those white marking low down on the bass side wing. They are an Oak trademark usually and won't be present in Ash.

Good luck with it! Look forward to seeing it restored

Edited April 24, 2016 by Manton Customs

[Andyjr1515]

[quote name='Manton Customs' timestamp='1461541089' post='3035587']
With the grain orientated like that on the back it'd definitely cause issues like seam separation if given half a chance (such as damp conditions). I'd probably replace the back if possible for that reason, as it could happen again!

Your guesses on the wood species sound about right to me . Definitely looks like an Ash top with Mahogany and Maple. The back could also be Ash, but it appears to have those white marking low down on the bass side wing. They are an Oak trademark usually and won't be present in Ash.

Good luck with it! Look forward to seeing it restored
[/quote]
Really interesting stuff ref the white markings - I wouldn't have known that's an oak signature

[Joebethell]

Looking forward to seeing this saved!

[Andyjr1515]

Started the exploratory stages today. These included:[list]
[*]Will it be possible to remove the split sections?
[*]How strong is the glue that [i]hasn't[/i] failed?
[*]Does the truss rod work?
[*]Will the neck be usable and, if so, will the neck angle be able to accommodate Mick's preferred Tune-o-matic bridge arrangement.
[/list]
The first thing to do was to make sure that the split in the body didn't extend all the way up the neck while I was moving things around. Presently, the split in the one thru-neck splice through the body extends to - but thankfully not past - the heel. I put on a violin clamp at the heel that stopped any inadvertent widening of the split from the heel upwards:


...and, when access would allow, clamped the body to try to put minimum strain on the existing crack:


My first target was to see just how easily the 'almost off to start with' rear right layer would come off.

The answer is - not very easily at all. Considering that 90% of the layer was already showing daylight, the final 10% was an absolute beggar.

I tried steam - lots of it at pretty high pressure directly into the gap - using a steam mop adapter:


I used a spatula, heated to almost red hot. I used a stiff scraper, again very hot. I used a pull saw, heated. I used stainless steel acoustic side bending sheet:


In the end, I got the big bas***d out:


Even once I'd got the whole section free at the bottom - and the side was already cracked at the glue joint halfway, like this:


... it still took hot knives, sharp knives and - in the end - a few chisel blows to finally release it:




With it having taken me about 4 hours to get this off, with pretty much all the tools and techniques you would expect for a job like this - and remember it was 90% off to start with - I have drawn a few initial conclusions:[list]
[*]The glue joints that haven't already failed are probably OK. When I was trying to release the edge of the section above, if the glue had been brittle, it would have just snapped off once I could start levering the whole thing. It didn't! It took me another hour of hot knives and platters and, in the end, a chisel, to release it.
[*]I think it would be almost impossible to get any of the remaining split panels off (the worst have less than 25% separation) without something irrevocably splitting or snapping. So for the others, I think it is a 'clean it up as best as possible in the splits, force glue in, clamp very tightly'
[/list]
Other things I checked were:[list]
[*]the truss rod - I [i]think [/i]that works well enough. I certainly works, although I don't know yet whether there is enough adjustment
[*]the neck angle. To fit a TOM bridge almost certainly will mean routing a slot for it to sit low enough for a decent action. Early days yet for that discussion because:
[*]...the frets may have to come off anyway and the fretboard re-radiused and refretted. The frets are all over the place, although the neck itself seems relatively warp-free. I'm not certain there's enough metal to be able to sand them down enough for a straight starting point
[/list]
Anyway - that is all academic unless I can glue the body back to the required stability...that will be where I focus my ponderings and tests and trials.

Edited April 26, 2016 by Andyjr1515

[Andyjr1515]

[quote name='Manton Customs' timestamp='1461541089' post='3035587']
With the grain orientated like that on the back it'd definitely cause issues like seam separation if given half a chance (such as damp conditions). I'd probably replace the back if possible for that reason, as it could happen again!

Your guesses on the wood species sound about right to me . Definitely looks like an Ash top with Mahogany and Maple. The back could also be Ash, but it appears to have those white marking low down on the bass side wing. They are an Oak trademark usually and won't be present in Ash.

Good luck with it! Look forward to seeing it restored
[/quote]
I think you're right about the back being Oak. The end grain that can now be seen on the edge of the section I've got off, looks just like Oak end grain.... Thanks for the tip-off

[HowieBass]

I think there ought to be TV shows about this sort of instrument restoration work - 'Bass SOS' anyone?

[Manton Customs]

[quote name='Andyjr1515' timestamp='1461686134' post='3036765']
I think you're right about the back being Oak. The end grain that can now be seen on the edge of the section I've got off, looks just like Oak end grain.... Thanks for the tip-off
[/quote]

No problem, glad I stopped by and found the thread, it looks like it's going to be fun to watch . It definitely looks even more "oaky" in the latest pics. Those pale white markings I mentioned earlier are called Medullary Rays if we are going to be technical.

I'd be tempted to rout the other half off as it was such a pain to remove! Then give it a new back with the grain running the right direction. But maybe that's part of its character!

Edited April 26, 2016 by Manton Customs

[Norris]

[quote name='Andyjr1515' timestamp='1461686134' post='3036765']

I think you're right about the back being Oak. The end grain that can now be seen on the edge of the section I've got off, looks just like Oak end grain.... Thanks for the tip-off
[/quote]

My eyes are not that bad yet then I'm pretty hopeless at the "guess the wood" game though

[scojack]

American white oak wood be a good possibility

Edited April 26, 2016 by scojack

[Andyjr1515]

I've done a lot of pondering on this and am probably going to go the Andyjr1515 unconventional way. Experienced luthiers might want to look away

My logic is this. The conventional approach would be to either:[list]
[*]Judge that the bass is irrecoverable
[/list]
or[list]
[*]Take it apart absolutely bit by bit and rebuild
[/list]
My approach assumes:[list]
[*]To attempt to take it apart bit by bit would probably render it irrecoverable anyway
[/list]
So, the unconventional approach is this:[list]
[*]Secure the central split to ensure there is no unplanned parting and splitting of the neck woods while wrestling with the remaining loose body panels. This may be temporary or permanent.
[*]Attempt to remove the two remaining water-split body panels. This will confirm if the glue that is still stuck really is as tight a bond and that it is as resistant to 'normal' de-glue and disassembly approaches as I think it might be.
[/list]
If they come off more easily:[list]
[*]dissassemble where necessary and possible
[/list]
If they don't come off then, rather than abandon the project, instead simply switch to a pragmatic and empirical approach:[list]
[*]Floss, clean, glue and clamp the splits
[*]Drill a stabilising dowel through the heel laminates
[*]Fit (budget) bridge, nut and tuners
[*]String it up and check the stability, straightness and adjustability of the neck
[*]If it's not OK, proceed no further and knock around the options with Mick
[*]If it [i]is [/i]OK, then put the effort into the pickup, electrics and finishing preparation and the financial outlay into the pickups
[/list]
Whatever, that central split needed to be stabilised:




I spent some time this morning carefully 'flossing' with sandpaper until the sawdust from both sides consistently came out wood-coloured (the crack is conveniently all the way through allowing 2' of sandpaper to be pulled through at each stroke ):



Then, significant squeeze-in and distribution of Titebond Extend before some serious sash-clamping and screw-clamping. Based on the squeeze-out at both sides, I'm pretty sure the glue got everywhere:


Got a gig this evening, so I won't be tempted to touch it until tomorrow

Edited April 29, 2016 by Andyjr1515

[Andyjr1515]

To most of you, this will look exactly the same...but to me this makes me very, very happy :



No crack in the middle. What's more, with lots and lots of weight on either wing trying to intentionally break the back, no movement, no gaps, no creaks.

Clearly, it's only when the strings are on under full tension that you know for sure, but I'm beginning to think that this might be strong enough...

In the meantime, I'm cleaning up some of the smaller splits on the other side of the back to see if I can stabilise those in a similar way.

[Joebethell]

Good work hope it holds!

[PlungerModerno]

Promising - There will always be some internal stresses in the wood - hence wood will always tend to shift when dimensioned / redimensioned.
With solid glue joins like the ones you've put on those surfaces you should be golden for the forseeable future. You'll know pretty quickly (or as soon as it is strung up & tuned)

[Andyjr1515]

A couple more evaluation checks and a bit more progress.

Mick wants a Tune-o-matic bridge with stop-tail. Normally, the neck angle in a thru-neck would be predetermined at the build stage, usually with a 3 to 5 degree angle to match the height of a tune-o-matic. This has been built flat-angled for a standard low profile bridge and I needed to calculate whether a T-O-M could be accommodated, both in angle terms and position of the stop tail.




I think - with a Warwick-type recess for the T-O-M to drop around 4mm - I can get it low enough with the existing angle. The stop tail will also be low enough for an adequate break angle. The combination will probably cover all but a single row of existing predrilled holes used for the old bridge.

I also spent a long time cleaning up the crud in the split between one of the mahogany body sections and the maple layer next to it.

I have some HUGE clamping force on this with some very good glue. Based on the squeeze-out and the very thin remaining joint line, I think it's clamped as well as it could be so will be a decent test for stability when the strings are put on for the final strength evaluation:



Mick's sending me some tuners and strings this week. It should be ready to string up for the final strength-based feasibility part of this project which will include the effectiveness of the truss rod. That should be done by early next week. If all goes well, the major steps will then be:[list]
[*]Strip down, sand, and reform the joint lines
[*]Defret and re-radius the fretboard
[*]Re shape the neck to accommodate a narrower nut (present is a massive 47.5mm)
[*]Refret
[*]Route out for pickups and electronics
[*]Refinish
[*]Reassemble
[/list]
Fingers crossed it all holds together to render those steps necessary....

Edited May 3, 2016 by Andyjr1515

[scojack]

Serious clampin' !
Looking good so far Andy