VSO #5 episode 2

its time to make the top.

i bend most of my tops, as oppose to carving them. more info can be had about bent tops here:
Athanas Lolov  http://www.jstor.org/pss/841136
Charles W. Gadd ( http://www.scavm.com/Gaddbd.htm)
William Fulton (SCAVM also)
Helen Michetschläger (http://www.helenviolinmaker.com)
David Langsather (http://www.dalemfg.com/opus_019.htm)

there is brief mention of it here:
http://www.maestronet.com/forum/index.php?showtopic=120833

my process here is more limited and archaic. it starts with a pair of book matched sitka guitar tops i bought from Bob Tibbetts. i like his stuff the best. he calls the planks i prefer "grade 3", the lowest quality he sells, but they are great for bending, and the wide grain has a very "viola" look to it.

the stability of bent tops is questionable. it seems logical they "unbend" or warp over time. in my limited experience, i have to say i have never seen an old top that wasn't warped in some way, so i am not really concerned. i still have a top i bent and glued together with crazy glue in 2007 that i put on the dashboard of my car for months just to see if it'll hold. it did, and that's good enough for me.

to bend these planks, i will need a bunch of clamps, some clamping cauls, wedges to force the planks to arch and a heat gun to steam the planks into shape.



after the viola form is drawn on the thin planks, i cut them out with a band saw and soak them in a (dirty) shop sink of water overnight.


i start the clamping process the next day first by clamping the ends lightly together and forcing the planks apart at the center with a wedge, taping it in with a hammer a bit at a time while heat is applied, along with water from a spray bottle.

more clamps and wedges are added and adjusted to get the shape i want. in this case, a split crack has occurred at one end on one of the planks. i decided to continue with a quick fix involving forcing glue in the split and then spot wedge/clamping the sucker.

i am cautious about forcing the planks to bend any more because of the crack. thus arching is maxed out at about 15mm. which means it'll shrink back to 13mm or so after it dries. some planks will allow me to get as much as 18mm+ out of it, some planks somewhat less. i use whichever by happenstance.

to be continued...