BYO: The Pliage

bill raymond

Someone inquired above about the weights Pete was using when he glued his soundboard.

As I recall, Pete had had some discussions with Jon LeVoi and also David Hodson about this, and I believe it was LeVoi who told him that he took a little extra material out of the soundboard halves at each end of the seam, sort of like making a dart in a piece of clothing, so that the top would form a shallow cone with the high point at the pliage, then clamped the edge of the soundboard halves while weighting the seam itself to clamp the joint.

That is why, I believe, that he has placed weights (not magnet, I don't think) on the top as shown in the photo of the glue up.

Peter Davies

I'm glad the Maccaferri project building log has been of some use. I think, Craig, you've come up with a great way of bending the pliage. Is it OK to add it to the list of techniques?

The pliage issue is still a mystery to me. It seems the people who've actually seen the originals don't concur on whether there is a scored line under the dome. It would be nice to see pictures of some originals (with their original tops).

So far I've seen a couple of a restoration (No 436) on Benoit de Bretagne's site -
http://www.benoit-de-bretagne.com/phpBB ... php?t=1134

There's also a picture on Frank Ford's taken with his Spycam -
http://www.frets.com/FRETSPages/Luthier ... ycam2.html

No sign of a scored line in the small photos though.

So the bottom line is - does anybody out there know anything?
But then, that would spoil the fun wouldn't it?

All the best,
Pete

Craig Bumgarner

Peter,

Welcome to the BYO Selmer subforum (sounds pretty subversive eh?) and thanks for your comments. I see what you mean about the mystery. We know how to make one but not exactly sure how Selmer did it. Well, next time I have my hands on a Selmer, me and my little mirror will have a look and I'll let you know what I see. I don't have many opportunities, but I do make a pilgrimage to Jacques Mezzaloni's every couple years and he is kind enough to indulge my curiosity even though I'm not buying.

Oh, and certainly okay to add my method to your website.

Craig

bill raymond

I just received an email from jazz guitarist George Parry. George was a friend of the late Louis Gallo, and also knew Marco Rocca at Clifford Essex. Being left-handed, George has made several Selmer style guitars, out of necessity. He has, through his association with the above-mentioned men, had the opportunity to examine the undersides of the soundboards of Selmer guitars. He tells me that there was no scoring. Although he did not say so directly, he also seems to dismiss the "bent over a hot pipe" theory, as he feels that Maccaferri, aware of the variability in workers' abilities, set up a production that would assure consistent results, and wasn't even present at the factory for much of the production; he feels that the iron clamping frame shown in Charle's book was used to create the pliage.

I doubt that it makes much difference just how the pliage was or is made, but rather that the method produce the desired result.

I hope that pretty much sums up everything we need to know to create the pliage.

Note that the pliage in the Ibanez Maccaferri guitars was apparently a true cranked top, and that's a different matter entirely; though it seems to continually confuse the matter.

Bones

I'm coming in late to this thread.

If you bend the pliage all the way across, how does it mate with the sides? Do the sides on original Selmers have a 'V' shape to the edge that mates with the 'V' shape of the pliage?

thanks

Craig Bumgarner

Bones wrote:

If you bend the pliage all the way across, how does it mate with the sides? Do the sides on original Selmers have a 'V' shape to the edge that mates with the 'V' shape of the pliage?

I believe the sides of Henri Selmer guitars and all replicas have sides with relatively straight edges, there is no V at the pliage. Even if creased all the way across the top, the top will straighten itself out as you clamp to the sides, it has to. The side rigidity is much stiffer than the top in this matter.

This is a minor aesthetic issue. If you make a hard fold all the way across, to me, it looks a little overdone, though I gather this is how Henri Selmer Co. did it. If you taper the fold, it looks better, at least to my eye. It can also be argued that folding the top at the edge and then straightening it out again doesn't do the top any favors. I got on to this idea tapering the fold because of the comments of Bill Raymond in his post earlier in this thread. I also like the comments about putting the "dart" in the glue edge to dome the part of the top below the pliage, but have not tried it yet. It can be tricky gluing up the top with pliage and trying to force a bend in at the same time sounds challenging.

Which brings us to Busatos. I don't know for sure, but I'm guessing the Busato bombe is formed by darting the edges of the top pieces. Busato used more than two pieces for the top perhaps to have multiple darts to form the rounded shape, kind of like a lute back. If anyone has more info on this they would like to share, maybe they can open a BYO: Bombe thread.

Craig

Craig

pzwinakis

The sides are straight (on a plane). The pliage transitions to nothing right at the edge. Probably by the top being forced into position when it was mated to the sides. The pliage does go as far as possible towards the edge. As far as scoring of the top before bending. Selmer did not do that, at least not later on. I have looked with my own eyes at the bend on a couple oval holes and there was no scoring. As far as how they bent it. Sure looks like a hot pipe helped do the job.

Bones

Ok, the tapered Pliage makes sense to me. No point in bending all the way to the edge and then trying to straighten it out when gluing to the sides. As you say, Craig, it may not hurt anything to re-bend it back but it doesn't seem like it would do the top any good.

Two questions remain:

1) If I use Craig's bending method rather than the hot pipe, how do I accomplish the taper.

2) Isn't the top also somewhat radiused in the long and short directions (as evidenced by the templates for the braces in the Collins book)? How does this play into the shape of the top and sides when combined with the pliage?

Thanks for all the help!

Craig Bumgarner

Bones wrote:

Ok, the tapered Pliage makes sense to me. No point in bending all the way to the edge and then trying to straighten it out when gluing to the sides. As you say, Craig, it may not hurt anything to re-bend it back but it doesn't seem like it would do the top any good.

I wouldn't worry about it too much. I was looking at the guitar I most recently made with the fold going all the way across and it really looks just fine. I know I started this, but tapered, not tapered, much adieu about very little.

Bones wrote:

Two questions remain:

1) If I use Craig's bending method rather than the hot pipe, how do I accomplish the taper.

Just don't clamp down as hard on the outboard side. This will be obvious once you do it. By not as hard I mean on the outboard side, clamp the top within about an 1/8" off the bench, where as the inboard side should be clamped down hard to the bench. Be careful to have a clean surface on you bench or use a dedicated piece of MDFB or you will injure to soft top wood.

Bones wrote:

2) Isn't the top also somewhat radiused in the long and short directions (as evidenced by the templates for the braces in the Collins book)? How does this play into the shape of the top and sides when combined with the pliage?

If you use a pliage, viewed from the side, the centerline of top is straight from the pliage to the head block (there is usually a little dip around the sound hole, this is not intentional, just a result of string tension). Viewed from the side, the sides are also straight at the edges. The only arch is across the body as introduced by the cambered bracing. The pliage takes care of the drop to the tailblock. The overall effect though is that the top rises in all directions to a high point at the bridge. This is all quite obvious from the Francois Charle plans which at $25 or so is the BEST investment you can make if you want to build a true Selmer replica. Only having a real one in hand is better.

Without a pliage, the sides need to have a bit of curve so as to throw some arch into the top lengthwise. This is up to the builders discretion, I used a 15' radius sanding dish to arch shape the sides. I also shaped the lengthwise braces up by the fingerboard to 15' R whereas in a pliage top, these braces are straight.

Craig

Bohemian

Bombe... an extreme bulge

In furniture making Bombe ( pronounced bombay by many) is a bulbous dome...
In guitar making there is flat, curved, domed, amd bombay as the extreme. as seen in the Busato guitars.

In Benedetto's book, he plainly states that an excellent guitar can be made from off the shelf lumber. He further states that he uses kiln dried and air dried wood with similar results,. He shows a photo of a guitar made with materials at hand and says it has excellent tone and playability.

Theoretically a plane can only be bent in one direction... guitar making attempts to counter physics..
but wood is elastic to some degree and controlling the elasticity is where the luthier practices his magic.

There is an archtop builder who makes his tops without carving. Instead he uses several pieces of wood canted and formed into an arch with cutting the glued longitudinal edges on an angle.
He claims it works well, and also structually more sound than a carved arch top because it does not cut across the grain. Interesting concept.

LMI has some inexpensive spruce tops... keep in mind... tops are graded and priced by appearance which has zip all to do with a guaranteed acoustic result. There are too many other variables.

Also can't see why common birch should not be suitable for backs and sides. Gibson used it extensively. Cheaop and readily available