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Re: A very simple light box for checking seams
Posted: Mon Mar 07, 2016 3:14 pm
by John Link
Yes you did, Dave. And yes, I had read them. And yes, yes, I had forgotten. Looks like Brian rates the torrified top you have as quite good, though not at the very top of all the Stika he has tested.
Re: A very simple light box for checking seams
Posted: Mon Mar 07, 2016 3:23 pm
by Dave Bagwill
In a sense, the test did not really tell us anything about the efficacy of the torrefecation.
If I'd had Brian do a before/after test, that might have been more useful. I have my own set of deflection testing jigs - copied from Brian - but i don't have the sophisticated $700 software that he uses, so can't really do my own before/after comparisons.
OTOH it is a good piece of Spruce; anything above a final Q score of about 50 will yield an excellent top if handled properly.
I'd like to get a nice billet of italian/Carpatian/European spruce and have someone slice it up for me - wonder if we could do a 'group' purchase and save some $?
Re: A very simple light box for checking seams
Posted: Mon Mar 07, 2016 3:34 pm
by ken cierp
International Violin --- at one time they had European Spruce guitar sound boards for a very reasonable price.
Re: A very simple light box for checking seams
Posted: Mon Mar 07, 2016 6:56 pm
by Tim Benware
Re: A very simple light box for checking seams
Posted: Mon Mar 07, 2016 8:20 pm
by Dave Bagwill
Drool.
Here's my take on jointing torrefied Sitka - this is my second top and both have been very difficult.
I tried using a shooting board and a well setup plane; I bought that Veritas shooting sander - both of which work well on other wood. Not so much on this stuff.
What did the trick was first, the light box to show exactly what was what; then I reverted to something I used early on and it worked very well - chuck up a piece of flat material (3/4" mdf etc) tall enough to support the sides but giving plenty of room to grip them as well - and a straightedge (I use the veritas straightedge, a tip from Tim Benware long ago, thanks Tim) with sandpaper glued to it - into a vise.
A few rubs, turn around and put over the light box, mark lightly where you need to concentrate, a few more rubs and Bob's your uncle. For this torrefied stuff it is the only method I've found that works cleanly and easily - I do not have a jointer but even if I did, this wood is splintery and any snipe at all is going to make a bad day.