To regraduate or not...

[Matthew Tucker]

Originally Posted by Ken Smith

Here's a tip for you. If you tweak the thicknesses in the Top, work 'around' that Bassbar and leave a small platform build up of wood around it like a shelf. My Gilkes was made this way and also a full sized bass attr. to Maggini was as well.

Originally Posted by Ken Smith

the density of the wood itself will govern how thick or thin it can be. The width, length and arching, mainly the arching will also have an effect on the Top strength or lack of if flatter. Each bass must be individually evaluated for graduation and not according to some plans of a bass whether the model is true or not.

For the very reasons that Ken gives ... that every bass is different, and every piece of wood is different ... I DON'T think you should take Ken's tip

Its been discussed before, but the "shelf" on the co-called "Maggini" and the Gilkes seems to me more likely to be the result of graduation with bass bar in place. It hardly seems like a recommended thing to strive for just because it worked in those basses. or not.

Also, you should know that the graduations given on ALL Chandler's plans* are, according to him, taken from the one Busan model he copied while it was open at Heinls. I don't think he had the others open to measure. I don't really like his thicknesses, though they will work. But every piece of wood is different.

You have only given two measurements but the thicknesses sound, to me, pretty normal. 9mm in the centre isn't that thick. Have you made a map of the top with your gauge, at all points on the top? Probably most critical are the thicknesses near the edges, but as Ken said, the arching shape is important too. How would you describe that?

I think most luthiers would agree (do you?) that there are probably other things you should try first, like strings/soundpost/tailpiece/tailgut/bridge etc, that aren't so drastic as regraduation. Have you been down that path yet?

And how about posting some photos of the patient, and/or your graduation maps, in case anything stands out? Its a bit hard to say anything without seeing the bass.

Matthew

* including the plans of the "Amati" model, that everone now knows is probably not an Amati, any more than Ken's "Loveri" bows are Loveris! But it says "Amati" on the plans because Corky Davis had some documentation (right or wrong) and told Chandler thats what it was, so that's what he wrote. What else could he have called it? So those plans will continue to be called the "Amati" plans for as long as the plans are sold!