To regraduate or not...

[Matthew Tucker]

I don't see why I would have created a fault line? The bar is still set at a slight angle to the top grain. If I'd finished the regrad at a sharp line parallel to the top grain, maybe. But the stresses are still distributed exactly the same as they were before, because the bass bar is in the same spot. The top is just slightly thinner, and a little thicker immediately under the bar.

[Ken Smith]

Originally Posted by Matthew Tucker

I don't see why I would have created a fault line? The bar is still set at a slight angle to the top grain. If I'd finished the regrad at a sharp line parallel to the top grain, maybe. But the stresses are still distributed exactly the same as they were before, because the bass bar is in the same spot. The top is just slightly thinner, and a little thicker immediately under the bar.

I think Arnold means that if the platform is at a right angle 90 degrees with the Bar directly under it, sitting on it, it acts as a pressure point along the edges or the 'bar joint. I think that is what he is referring to rather than a gentle sloped platform in which the 'bar would sit. That's how the Gilkes is done. You can feel it but you can't see it that easily. It is slight but it is there.

[Arnold Schnitzer]

Originally Posted by Matthew Tucker

I don't see why I would have created a fault line? The bar is still set at a slight angle to the top grain. If I'd finished the regrad at a sharp line parallel to the top grain, maybe. But the stresses are still distributed exactly the same as they were before, because the bass bar is in the same spot. The top is just slightly thinner, and a little thicker immediately under the bar.

Yes, I see your point. I was thinking the cut-out under the bar was following the grain, but this is not really so. Anecdotally, though, I have seen a bass where the regrad was done this way and the top cracked badly. I remember it being pretty thin. And the wall of old top wood on which the bar sat was a good 4-5mm high.

[Matthew Tucker]

I've taken off from 1mm going to 2mm at the tips. I'm not worried structurally, but as I said, I don't think I'd do it again that way. And your words of caution are duly noted!