BYO - the top

bluemoves

My dad has no instructions to proceed from and is only experienced in building violins.

He seems to think he's got to get the two halves of the top to the correct thickness AND bend the 'pliage' into both BEFORE glueing them together..

That seems to me to be making things more difficult for no reason.. Why not glue them together first and then shave to thickness (I presume the top is a uniform thickness all over, right?) and THEN bend the pliage across the entire piece?

Any experienced tips would be appreciated!

billyshakes

Can't imagine how you could do it separately and get them to line up correctly. But I'm not a luthier.

Bones

There are some BYO Pliage topics. Use the search box in the lower right. I think most thickness the wood to CLOSE to the final thickness then bend each half separately then join the two halves. It's actually a bit tricky to line them up but you do need to make a form that will both set the precise angle of the bend and also keep the halves lined up for gluing. The tops are pretty thin and flexible so they can be clamped into near perfect alignment on the fixture but you do want to do a good job bending and fixturing each half to get the pliage as close to the right angle as you can or you will be fighting it during joining and also you need it precise anyway because the pliage and brace arch radii affect neck angle and bridge height.

Some have joined and then bend the pliage I think. I was nervous to try that since you need to use a fair bit of heat and some moisture to bend the spruce and I didn't want to compromise the glue joint on the center seam as heat and water will weaken most all adhesives.

billyshakes

Goes to show what I know! Thanks for chiming in @Bones . It does make sense that the heat would compromise the glue joint.

Bones

I leave them just a hair thick so if there is any slight misalignment I have something to play with. But that said if you fixture it properly in a go-bar deck they should be spot-on.

Oh and FOR SURE do a "dry fit' in the fixture to make sure everything is perfect before you try gluing. As a visual guide I like to draw a few light, straight pencil marks across the glue joint during the dry fit when I have everything lined up so I have a visual guide while gluing.

bluemoves

Ah, OK, I get it.. it's about not compromising the glue joint with the heat and moisture..

That makes sense!

Thanks so much for you input chaps! It's a tough path to walk with no guides :D so, I appreciate it. A lot.

Bones

All that said, I do believe that some do join the top first then bend and are successful. I'm just saying how I've done it. Also part of the reason I do it that way is I can bend it over a hot pipe and I only do the full pliage in the middle since the edges of the top where it mates to the sides is flat anyway. I taper the pliage to nothing at the outer edges. I didn't see the point to bend the pliage all the way across only to force it flat again on the edges when bonding to the sides (which are flat along the mating surface with the top, i.e. the sides do not have the contour of the pliage, if that makes sense I know I'm not explaining it very well).

bluemoves

Guys, another kwick kwestchun - thought I'd ask here rather than start another thread..

re: Top bracing

The long shallow brace that runs down the top's glue line..

Is it 'sectional' (as in, does it skip the lateral braces)?

Or is it one piece and each brace notched to pass over it?

Thanks oracles!

(pics soon, I pwomise)

Bones

That's not really a brace, it's more like a reinforcement for the center seam. No clue how the originals were made but I did not notch my lateral braces. The reinforcement is not continuous, separate pieces between braces.

crookedpinky

I've only built two but I always notch the cross braces as my centre joint reinforcement runs from the tailblock to the soundhole.

pdg

For regular (non-GJ) guitars, this reinforcement strip is only on the back (because the tops are thicker). And the back braces go continuous across the back, for structure and sound transmission (even more important for the top).

You can glue pieces of the reinforcement strip between the brace locations (line them up!). Or, glue one long piece, after having put wax or something where the braces will go, and then chisel out those parts and fit the braces in there.