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  #1  
Old 12-03-2015, 06:27 PM
rogthefrog rogthefrog is offline
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Default First try at building

After a lot of "studying" and asking questions (thanks to all the luthiers here and elsewhere who've patiently answered them), I finally decided to jump in and build a guitar-shaped object and started today.

Because the odds are excellent it will be a disaster, I'm going with the "whatever orphaned bits of wood nobody wants" option from RC Tonewoods, which this time around consists of:

* "student grade" cedar top (which is nonetheless pretty resonant, with a Bb tap out of the box)
* birch back and sides, OM-sized
* Adirondack spruce brace blanks
* maple bridge plate
* Spanish cedar neck, pre-cut
* mahogany neck and tail blocks
* makore bindings
* EIR everything else (bridge, fretboard, headstock overlay)
* a growing collection of salvaged hardwoods and ply for jigs, etc.
* tools I mostly inherited from my contractor / cabinet maker father-in-law when he passed

Today was spent preparing for jointing the top and back halves and testing my carving skills on actual hardwood (I have a spare bridge blank for practice):

* dusted off an old but functional router for saddle slots
* rehabbed a good but old, dull and rusted out hand plane--now it's clean, functional, true, and sharp
* made this jig to join tops and backs. The glued-on strip of redwood will anchor the left side; the right side will be ringed by nails and wedges pushing the right half towards the left, clamping the center glue joint tight; and the bits sticking out on both sides of the jig will receive rope or twine wrapped around the top, holding down a 2x6 on top of the joint.



The jig is inspired by something like this:



My goal with this thread is to document it for my own sake, entertain woodworkers with my ineptitude, and (ab)use advice any luthier foolish enough to read this may be willing to dispense.

We could call this Chronicle of a Disaster Foretold. Let's see how it goes.

Next time:

* true up the edges to be joined on the top and back, and join them
* make body, bridge and headstock templates
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  #2  
Old 12-03-2015, 06:57 PM
difalkner difalkner is offline
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I'm about 2/3 complete on my first build followed closely by about 1/3 complete on my second (glutton for punishment...) but not near as brave as you. Not a single photo until I finish, and then only if I like what I've done. So my proverbial hat is off to you, Rog!! Looking forward to seeing the next steps.
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Old 12-03-2015, 07:25 PM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by rogthefrog View Post
... The glued-on strip of redwood will anchor the left side; the right side will be ringed by nails and wedges pushing the right half towards the left, clamping the center glue joint tight; and the bits sticking out on both sides of the jig will receive rope or twine wrapped around the top, holding down a 2x6 on top of the joint.
If the joint fits together well, it doesn't require a great deal of force during clamping. The nails and wedges are sufficient. Provided you don't use excessive force - buckling the two halves being joined - you don't really need the 2x6 on top of the joint to keep the two sides flat: looping rope over top of the 2x6 isn't going to provide much downward force on the two halves of the joint. It is a different approach to the sticks, wedges and rope method. If you find you do need the 2x6, just clamp it at its ends rather than use rope. If you slightly round the bottom of the 2x6, along its length, that will provide adequate pressure in the middle when the ends are clamped.

There are many methods that can be used to glue/clamp the two halves. The simplest involves two heavy bricks and a length of masking tape. Doesn't stack very well, though.
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Old 12-03-2015, 07:42 PM
rogthefrog rogthefrog is offline
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Good to know! Thanks, Charles.
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Old 12-03-2015, 08:14 PM
rogthefrog rogthefrog is offline
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Quote:
Originally Posted by difalkner View Post
I'm about 2/3 complete on my first build followed closely by about 1/3 complete on my second (glutton for punishment...) but not near as brave as you. Not a single photo until I finish, and then only if I like what I've done. So my proverbial hat is off to you, Rog!! Looking forward to seeing the next steps.
Come on, pix or it didn't happen!
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Old 12-05-2015, 05:47 PM
rogthefrog rogthefrog is offline
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Today I trued up the inside edges of the top and glued them.



Turns out I did use the "hooks" I cut out on my joining board, because I don't have a long enough clamp to clamp down the center block, so I used rope and wedges to hold that down. I also added an extra nail and wedge on the bottom corner (not in the picture).
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Old 12-05-2015, 06:23 PM
Tom West Tom West is offline
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rog:
Nice to see you giving a go at building. Notice you are working outside. Wonder if you are aware of the implications of relative humidity...? Generally guitars are built in a RH of about 40%. Some way to measure and control RH prevents problems down the road.
Tom
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Old 12-05-2015, 06:28 PM
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murrmac123 murrmac123 is offline
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Tom's just jealous ... he hasn't seen sunshine in three months ...
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Old 12-05-2015, 06:43 PM
Sam VanLaningham Sam VanLaningham is offline
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Way to go, rog! Good luck. I like the start so far.

Sam
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Old 12-05-2015, 06:59 PM
rogthefrog rogthefrog is offline
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Quote:
Originally Posted by Tom West View Post
rog:
Nice to see you giving a go at building. Notice you are working outside. Wonder if you are aware of the implications of relative humidity...? Generally guitars are built in a RH of about 40%. Some way to measure and control RH prevents problems down the road.
Tom
Yes, it's been a concern of mine. I don't have a good spot indoors to do the really dirty stuff, but I'll bring things inside asap.
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Old 12-05-2015, 08:11 PM
dekutree64 dekutree64 is offline
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It's fine to work in high humidity for a lot of stuff. Cross grain gluing is where you run into trouble. Rosette, bracing!!, gluing the plates to the rim, gluing the bridge.

Gluing the fingerboard extension to the soundboard can cause trouble if the fingerboard is ebony, simply because its humidity expansion rate is so high. If both are acclimated to 70% when you glue up, and then you take it into 30%, the fingerboard will shrink significantly more than the soundboard and may cause the common fingerboard edge cracks, like this:


Rosewood has about the same expansion rate as spruce, which is still higher than cedar, but unlikely to cause any trouble.

Filing down the fret ends level with the edges of the fingerboard is another time you want to be acclimated to low humidity, or else they'll poke out in low humidity later on.

But pretty much everything else can be done in uncontrolled humidity.
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Old 12-05-2015, 08:25 PM
rogthefrog rogthefrog is offline
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That is great information, thank you.
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Old 12-06-2015, 07:31 AM
Tom West Tom West is offline
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Quote:
Originally Posted by murrmac123 View Post
Tom's just jealous ... he hasn't seen sunshine in three months ...
Mur: Think we are in luck.................I see a bit of blue showing today...!!
Tom
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Last edited by Tom West; 12-06-2015 at 12:00 PM.
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Old 12-06-2015, 05:50 PM
rogthefrog rogthefrog is offline
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After 24 hours, I took the top out of the clamps, and much to my surprise the joint appears to be solid. I candled it with a bright flashlight and it's tight except at one end that will be cut off. So I'm calling this a success.

RC tonewoods indicated this student-grade top isn't as stiff as they would like, and it does feel very floppy (though I've only ever handled one other top, the Italian spruce top for my harp guitar, which may have been chosen for extra stiffness to handle all those strings). So I only took a little bit off with a hand plane and coarse sandpaper. I'll sand more tomorrow and call it done until I get a scraper to take care of the glue squeeze out on one side.

Next up: same thing, with the back. If the back works out well, I'm feeling bold and will attempt to put in a strip of contrasting wood across the joint to pretty it up. The back and sides are very white birch and I will almost certainly stain them darker.
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Old 12-06-2015, 06:14 PM
rogthefrog rogthefrog is offline
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Question: I got a neck block and end block from RC tonewoods, but I also salvaged three blocks of an unidentified hardwood that are big enough to make a few such blocks. The wood is dark maroon/chocolate brown, and sands a bitnon on the orange side. There's no particular smell to it. I picked it up because it is extremely dense and heavy. Any idea what it could be?

Here's the mystery wood, next to mahogany for reference:



One of the mystery blocks isn't much bigger than the mahogany block:



The mahogany block is 6.50 ounces, and the mystery block is 16.03 ounces (!).

I did some math:



The mystery wood is 1.68 times as heavy as mahogany.
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Last edited by rogthefrog; 12-06-2015 at 06:49 PM.
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