Thread: #2 Build N. Silky Oak Classic

Week 7:
As it turned out, day off didn’t materialise, and with the weather continuing foul in the main, I didn’t get much done this weekend.
Did get most of the backlog around the house done however.

What did get done was the boring bits: Linings cut and facetted, tentellones cut, linings kerfed, ledge cut in headstock for the top, tailblock made, sides cut to template and bends touched up to fit ............... Ages to do, and nothing to show for it.

So now I’m poised for a big step change. Provided the weather plays along, (or I can improvise a full-size dry box), I’m ready, and have the time this w/e to complete the soundbox, which will be a milestone, (and will be accompanied with pics)

Wish me luck, and offer a libation to the weather gods for me........


regards

Week 8.

Well finally an uninterrupted week end on the build, with the weather playing along, and as a result some tangible progress.
But also a visit from the f#ck-up fairy, and a good one.
I should have seen it coming, as I had just congratulated myself on how well it was going.
Painstakingly aligning the soundboard centreline with the neck, and gluing and clamping. Then as last week’s weather continued, it needed to go back into the dry-box, and that’s where the problems started. Too big for the existing box, so I converted an old cupboard into a larger replacement. Even then, it could not accept the workboard, or even the instrument, with clamps attached.
Attachment 191632
Taken later, but shows the problem.
BUUUT the clamped joint had already set, so it was stable, so no problem.............NOT.
With the neck/soundboard standing as in above pic, the joint crept, until the centreline at the tailblock was off by ½”. What was more important, however was that I didn’t recheck. After all, I’d done the setup, and the joint was set. (wasn’t it?)
So it was on to gluing on the tailblock, and trimming and fitting the sides. Strangely, they didn’t fit as well as in the freehand check I’d done before.......... must have moved with the humidity.
Soooo, laboriously fitted to the best compromise, wedged in the heel, glued and clamped at the tailblock, and set to with the HHG and the tentellones.
A long aching back day later, it was back into the dry-box.
Next morning I pull it out, and proudly display to the family, and only THEN do I sight down the neck, and see the kink.
Fixing now presented a conundrum. Glued at the tailblock, and heel wedges superglued into the slots, so a complete disassemble wasn’t possible. In the end I took what seemed to be the route of least risk.
As the problem was manifest in the upper bout, I carved off the tentellones between the upper cross strut and the heel. Then I heated the joint between heel and soundboard with an iron, while applying corrective pressure. As the glue softened, I was able to pull the neck back in line, and then reclamp and allow to cool. Alignment was corrected, but there was collateral damage. With the heat, the soundboard joint also softened and opened up about 1/2mm, (fortunately only as far as the UTVB.) I’ve added a spruce graft in the space between the UTVB and the heelblock, and wicked superglue into the crack. All that’s left is the prayer that the neckjoint stability hasn’t been compromised.
The rest of the w/e was a bit anticlimactic in comparison. The tentellones in the upper bout were redone, and the back arched. Kerfed linings applied and levelled, and the back brace-ends and pockets cut, ready for roping on the back.
Attachment 191633 Attachment 191634
However, by this time, it was Sunday evening, the humidity had got to everything again, and I needed leccies and stuff for the roping, so further progress (hopefully) this week.
I really would like the box closed before Xmas, as I have a 3m sliding door arriving this week, which will hold me up for a while.
regards

As noted over on the ANZLF forum the problems you're having relate to releasing the guitar from the workboard before the back is glued on and providing support for the Spanish foot.

For roping up I use dress makers bias binding tape.......usually the 3/4" or 1" wide stuff works for me. Macrame rope is another option.

Cheers Martin

I dont think Ive ever built anything without a visit from the fairy. The good bit is that you can unglue the box and fix it. Im curious to hear more about your opinion of a dry box. I doubt I could even make one at the moment The monsoon has moved south.

Originally Posted by Sebastiaan56

I dont think Ive ever built anything without a visit from the fairy. The good bit is that you can unglue the box and fix it. Im curious to hear more about your opinion of a dry box. I doubt I could even make one at the moment The monsoon has moved south.

Hi Seb,

Up until now I've thought of it as useful, and certainly, it has helped me to keep going recently.

I think I can confidently say that without, I would have had (at least) soundboard and back going into reverse bow, when the weather dried. As it is, when I've had parts out into the humid air, they have tended to increase bow, which is healthier?????

Hard learned lesson from above is to be sure that it is big enough to take the whole assembly, wb and all, (or mould etc).
From my perspective, I would stay with the dessicant, rather than a light or heater: as if left on, or in drier weather, these could continue to lower RH to disastrous levels.
Once you get down to the equilibrium point of the desicant, however, it ceases to absorb, (and may actually release moisture if the air dries out further?)

There was a thread on ANZLF a while ago, where a couple of the guys up north had contributed some info as well.

regards

Alastair,

When building spanish method I generally only get fussy about humidity and the top while the top is being braced and before the sides go on. Once the top is on the workboard and sides are on the top is fairly well supported and isnt going to warp.

On a positive note...your problems are pretty much run of the mill for a beginner. If it was all straight forward and easy it wouldnt be as much fun!

Cheers Martin

Week 9
Early update, for a couple of reasons:

Not working next week, so probably too NAAFI to log on.......... we’ll see.
Also I have a 3m tri-panel glass sliding door to install next week, which will keep me a bit busy.
Finally, BIG milestone yesterday

Despite the hassles of the last week, the box is closed, and it looks like a guitar.

Got the workboard ready, and with my version of roping, (BIG bag of No. 109 leccies from Officeworks), the back went on without problem.

Attachment 191873 Attachment 191874

After it came off the workboard, and the soundboard and back overhangs were trimmed, finally a good look at it.

Attachment 191875 Attachment 191876

At present it looks a bit pale, but with Imbuia bindings to match the back stripe, ebony fretboard and bridge, and with finish applied, it will acquire more definition.

Speaking about the backstripe, my lingering concerns from above have manifested themselves, however, and I fear this won’t be the perfect build I was pitching for.
The distortion introduced by the inlay is still there, in spite of the arch and bracing. For most of the back, it is minor, and will scrape and sand out, but there is a small area, between the lower bout brace, and the tailblock, where I think I will be left with a dimple, no matter what I do.

Unfortunately my planned FP finish will make this stand out like d#g’s b@lls, so I am considering a rethink to a satin lacquer instead. We’ll see how we go.

Two weeks off, to do things now, so a happy festive season, and see you in 2012.

regards

Originally Posted by kiwigeo

Alastair,

When building spanish method I generally only get fussy about humidity and the top while the top is being braced and before the sides go on. Once the top is on the workboard and sides are on the top is fairly well supported and isnt going to warp.

On a positive note...your problems are pretty much run of the mill for a beginner. If it was all straight forward and easy it wouldnt be as much fun!

Cheers Martin

Thanks Martin,

I think you should be talking to my ulcer, however.

The problem is I am as much a perfectionist as you, but without the painstaking skill

regards

Looking pretty good Alastair.

Time to take a rest from the rigours of guitar building and enjoy the festive season.

Have a great Christmas and New Year.

Martin

Week 11
Well, Xmas and New Year wishes to all, and on into 2012.
In between the festivities, spent most of the break ripping out the end wall of the rumpus room, and installing a 3m sliding door. Mostly done, except for replacing the weatherboard, and sheeting the interior, but took time.

So had a quiet 2 weeks regarding the build, but at least resolved the back issue, as far as I can see, until the finish goes on!

Thanks to some advice from the gurus on the ANZLF, I had the idea of relieving the stress in the backstripe.
I set up and clamped a meter rule, so I could score along the margins of the inlay with a craft knife, on both sides, down to the depth of the inlay. Initially no visible effect, but after wetting the area down, and allowing it to dry out, the back has resolved to convex all but for the bit between tailblock and lower brace, which has resolved to flat. Wicked thin CA into the cuts, and scraped and sanded back, with no discernable witness marks, (unless the finish brings them up).
Tailgraft installed, to match the back inlay.
Then on to the highest stress of the whole build............ routing the binding channels.

These were done on the router table, using a bearing straight bit, set up to give a 2mm x 6mm channel. To get this finished without any disaster, was a Christmas present in itself.
Imbuia bindings were bent on the hot pipe, and glued in using the same roping technique as above, with no gaps visible. Scraped and sanded back, the only slight detraction is the waist on the back, where despite measuring, the binding is just visible as narrower. I take comfort from No. 1 son, who told me “that is up against your stomach anyway...”. But I’ll know it’s there, as with the kink in the lower bout.
Not visible, but evident to the stroking hand. I specifically straightened this during final touch-up, but the “memory” which the SO exhibited some pages up, caught me napping again, and it came back before I finally got the box locked.

No pics to go with this post, but I’m taking the rest of this week off, so will post some when I get back.

regards

Week 12.
Firstly, the promised pics showing the completed binding.


Attachment 194150 Attachment 194151

That said, with being on leave last week, I made a fair bit more progress, despite sharing the time with the reno work, but unfortunately the camera battery died, so I’ll only post pics later this week.

In terms of progress, I got the fingerboard made up, slotted and tapered to spec, but when checking in place, found the clearance at the bridge position was below min. I seem to have some doming of the top across the bridge pad, but I can’t rely on that coming out when I glue on the bridge, so it was time to plane out most of the clearance I had just planed in!

Fingerboard was finally fitted, and frets installed, levelled and polished.

Basic neck carving is done, and I’m refining the profile, and doing the throat shaping. Working on the “slowly, slowly...” method, and referring regularly to quality control, (in my sons’ bedroom), as to final shape.

I’ll add some more pics tomorrow.

regards

Originally Posted by Alastair

In terms of progress, I got the fingerboard made up, slotted and tapered to spec, but when checking in place, found the clearance at the bridge position was below min. I seem to have some doming of the top across the bridge pad, but I can’t rely on that coming out when I glue on the bridge, so it was time to plane out most of the clearance I had just planed in!

Alastair,

Is this instrument a flat top or did you build the top in a dish an introduce doming intentionally?

Regardless of the answer to above question shape the underside of the bridge to accommodate the doming rather than flattening the top. This can be achieved by a bit of judicious work with a cabinet scraper on the underside of the bridge blank or you can attach some 120 grit sandpaper to the top in the bridge area with double sided tape and then work the bridge blank across the sand paper to profile the underside of same.

Cheers Martin

Ok it's a classical and you're working on a workboard with a dish in it so the lower bout is domed. Normal procedure is to shape the underside of the bridge blank to fit doming of the top as Ive described in previous post.

Originally Posted by kiwigeo

Ok it's a classical and you're working on a workboard with a dish in it so the lower bout is domed. Normal procedure is to shape the underside of the bridge blank to fit doming of the top as Ive described in previous post.

Hi Martin,

I'm working off he Cumpiano book, so the the upper bout is flat, but the lower cross strut is arched (I think 1/16th, or 3/32", can't remember, and the book is in the shed.

As braced, the fan brace/bridge area was pretty flat; the arch was higher up towards the waist. However, I have a feeling that with the increase in humidity after it all came out of the dry box, the expansion against the cross grain bridge patch may be adding a bit to the dome.

I notice that C&N specifies a dead flat bridge. I'll see what the clearance at the bridge is once I tsart on that, and decide whether to stick to flat, or slightly dome.

regards