Time to get moving on this project already! A couple of pieces of 150 grit sandpaper taped to the work table* removed the rough spots on the back of the top –

Careful pressure to be sure the surface was sanded evenly and Bob’s yer uncle – a beautiful smooth surface for gluing to the blocks and ribs. There’s really no question of sanding further to thin the edges of the plate – the back is pretty thick around the edges and the fiddle will be prettier if the plates match, so thick edges it will have.

Next I spent some time with a sheet of carbon paper** and the thicknessing gauge to determine where the inside of the belly needs some work –

There are about a million different versions of graduation patterns to peruse on the web, and they all differ, which each maker having a valid argument for their particular pattern and thickness zones. You can lose yourself in scientific research, tap tuning, vibrating plates and findings from museum instruments. How does a new builder decide what authority to go with?

In the end I decided to use Ossman’s basic graduation pattern as a rough guide for thickness zones, but I’ll be striving for an even, symmetrical graduation, not as thin as many believe is optimal because the spruce top has a pretty widely spaced grain, which should enable good vibration even if it’s a bit thicker than “optimal.”

At this point, the inside is fairly smooth, with a few tool marks, but is in no way symmetrically carved. There’s a thin spot*** on the lower belly on one side that will have to be balanced with an equally thin spot on the other side. The difference between the sides is quite dramatic in places – nothing like symmetrically carved and it will be a grand experiment to see if I can do better. Stay tuned…

Helper dogs watch attentively –

* The table was formerly used for drafting, so I’m reasonably sure it’s flat. Sanding on the glass-topped kitchen table didn’t seem like a good idea…

** Who uses carbon paper these days? Pretty much no one, judging by how hard it was to find. I had to buy 100 sheets at Staples, which is a supply that should last me about 17 lifetimes at this rate of use.

*** 2.75mm thick – we’re talking about fractions of a millimeter and a human caliper that is quite fallible, even on her best day 😉

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