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Still plugging away,


Used HHG to glue some triangular mahogany braces, 15' radius, onto the back.


And shaped them into a nice parabolic taper. Also fastened some diamonds between the braces to reinforce the glued up crack.

And then I got adventurous! I decided that this little guy would be the perfect place for my first venture into....
the land of the flying buttress!

So here's my poor-boy, backwoods version.






I didn't have any CF on hand so I flexed some dowel rod, not too stiff, and then I tried some good bracestock 1/4" x 3/8", and it was pretty stiff. So I figured it would be worth the experiment. I carved each end of the brace into a rough dowel shape and used epoxy to anchor them into the holes, and glued the buttresses onto the sides with titebond.

And it really stiffened the whole thing up really well. No back on and the neck feels strong. I think I'm going to like it!

I even got the back glued on just before dark, so tomorrow I'll definitely have a guitar shaped object to ponder!
Till then,
Joe

edit.... and yes I did fix those old kerfing pieces, before I closed her up.

Joe,

Way to go and welcome to the club. You don't have to use cf - Mike Doolin uses laminated buttress braces and I used spruce on the Harp uke. The way you have done them is similar to Rick Turner except he uses two cf ones going angled from back side to top side. It's amazing just how stiff the rimset is with the linings and buttress braces in place and at that stage you can throw your mold away The rimset is such a strong structure that using it to deal with most of the forces of the neck string pull on the instrument is such a no brainer.

The bracing of your top and back looks really nice too - but I would say that

All right Joe! How wide is the lower bout? Howard Klepper is using that basic buttress with CF tubes. I may try that one too. This is going to be interesting!
Another thought is to run this style of buttressing and add a couple of tubes from the tailblock to the buttresses. Hmmm...

Thanks Dave and Hanns!

I'm a convert! It's amazing how much the flying buttress stiffens the guitar, you can just feel the stiffness when you handle it, I'm a believer! Like you said Dave, it really is a no brainer, to transfer the string tension to the rim, such a great solution. I first became aware of the need for this on my long scale 12 str. When I would change from standard tuning to open G or D, I would retune the strings that change and then have to retune all the strings because of the tension change. Which tells me that the neck/body relationship was moving, and retuning all 12 strings, often more than once because of the tension changes is indeed a real pain. And my 12 has two cf bars and a hotrod trussrod in the neck, so the movement must be happening in the body.

Now the FB probably wasn't necessary on this little parlor, but it was a good place to get my feet wet.

The lower bout on this one is 13 1/4" Hanns.

I think I mentioned that I was going to try to get the back and top glued on here without removing the dovetail neck since it was tight. And as you can imagine getting all the angles right was a little tricky. So I had it going good with the top on and the flying buttress in place, neck line-up was good and angle was good. In fitting the old back into place I notice that the waist has spread a bit in the rims and the old back doesn't quite fit. So I wedge in a shim on each side between the temporary form and the side and pinch it in so the back covers nicely and glue and clamp it on.


As you can see, that sucker ain't getting away!

The next morning I unclamp it, great sounding thump, looking like a guitar. And then I re-check the neck angle, it changed. Too much angle. So I study and realize that when I pinch in the waist so the back covers nicely, naturally that brings the ends of the body up, changing my carefully sought angle. Now to fix that I think I'll try an old neck reset trick I'd read of where you "slip" the neck block on the back. Since the ends moved in when I pinched the waist there was plenty of overhang there.

So I get out the iron, start heating over the neck block and working the palette knife in, using a folded paper towel to keep the back from scorching. Get the end loose, pull up the towel and see that I've opened a nice new crack in the upper back also. I clamp the neck down to the building board, reglue the back, pushing the new crack back together and leave it overnight.

Next morning, pull it off the building board, check the neck angle, all's good. Hurray! Success! Start thumping again on the box checking out the new bracing and start hearing a little rattle. Come to find, when I used the iron to release the HHG from the neck block it also released the upper back brace. It's still in place, but you can work a palette knife under it from end to end.

Reglue the brace, and now all is good! Sure had me chasing my tail there for a while though. Focus on one problem and fix it, not noticing that the fix is screwing up something somewhere else. Ah the pleasures of guitar building!

Don't follow my path,
Joe

Joe,

Well we said we wanted to see more threads on repairs More inspiration from the mentor Percy V Rance - if you don't make mistakes and work out how to fix them you don't learn anything. Great stuff, onwards and upwards . . .

Yeah Dave, good old Percy, he can teach us a lot if we can put up with him!

Next up is routing for binding. This one didn't have a rosette or any binding to start with, so even though I'm going with plastic binding, , thick cream sandwiched with a thin black, it's quite a step up on this old guitar. First I laminated the black and cream together, using acetone and sliding them through a binding laminator that stew-mac sells. Works pretty good.

And here's my binding router set-up.

The tip of the wood base is tapered to allow me to keep the router vertical on the tapered guitar back. Spiral down-cut bit and the roller guide that came on the router. Not the best system perhaps but it doesn't do too bad.




Ledges cut, and then since the neck is already attached I had to do some freehand ledge carving around the neck front and back. Exacto knife and sharp chisel took care of that pretty quick.


And I got the back binding on last night.


And here's the top binding in place. I've got to say I'm kinda drawn to that big bold checkerboard binding!




Pull the tape off tomorrow and let the binding harden back up for a couple of days and then I can scrape them down. I tell ya, there's a place for plastic binding, maybe not on your finest build but it has it's place.

All for now,
Joe

Wow Joe, you are really making some progress. Lookin good.

Lefty

I'm gonna be interested in hearing about how this one sounds. Guess it's about an inch larger than my parlor. I'd love to use tone bars on everything!
I like to use celluloid binding on my best...guess it's just tradition...