VSO #5 ep.3

continuing with the top...

it's been a couple of days and i think the top and wedge sandwich is fairly dry. when the clamps are released, i get this:

 if i put them next to one another, i get this:

not exactly usable :) its time to shoot the planks on my make-shift shooting board:

the joining begins when no light peeps through the joint when both boards are held together. joining is done with crazy glue of course. one board is nailed to my bench and the other is pushed against it. crazy glue is squeezed onto the seam and the glue shoots through very quickly, accelerator is sprayed onto the joint to make the glue dry instantly. excess wood is cut off with the band saw.

the back is now nailed onto the over-sized top temporarily. this way, i can file the edges until both the top and back look the same. i pencil some purfling on the top is see how the corners look.

to be continued...

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...

Viola Shaped Object #5 episode 1

Hello world! I make Viola-Shaped-Objects. It's fun and requires no training!


i'm just now starting to make VSO#5, please join me for a good laugh if you like.

i begin my “process” by drawing. there are many things I like about many different violas, so I try to cram as many favorite qualities as i can in a Frankenstein instrument.

In drawing a “design”, I’m looking to put the bridge almost center on the top and keep a stop length appropriate for a 365mm string length, which works out best for my fingers. The stop length is the distance between the shoulders of the viola where the neck joins the body to the bridge of the instrument. This length must be within a certain ratio in relation to the length of the neck of the viola (nut to shoulder). Otherwise the instrument will feel out of proportion as you shift hand position.

here's an interesting article about those proportions i'm referring to in pdf: http://www.maestronet.com/m_library/violin_violinist/19431210.pdf

another thing to consider is the width of the middle C-bouts. on my first viola, the bouts were too wide, bowing the C or E string (5 string) meant bowing onto the bouts. the neck has to be reset at a more acute angle to compensate. i'm not the first to encounter this of course, have a read here.

you'll find i won't offer much by way of measurements and templates, i don't how how. every instrument is about deaing with whatever i happen to get closest too. the arching on the back for instance is determined by how thick my planks happen to be, i don't own measuring calipers, so everything is done by touch and eyeballing the sucker.

things in my life seem to happen backwards, so back starts making with. I bought this $35 two piece maple back from International Violin Company and proceeded to try and join the planks. this is hard stuff... I spent 3 hours planning ½ an inch off each side and still couldn’t get the halves to join seamlessly! i prefer one piece backs because there is less work to do. plus one or two makes no provable difference in sound.

I can keep going and will probably join it eventually, but what am I going to do with a ½ size violin?

on with "Plan B"

Plan B requires me to rough out the back arching on both planks with my Wecheer powered carver (my favorite little monster) and then plane them on a make-shift shooting board. The thinned edge on both planks makes it easier to join. Joining is done by nailing one plank down and wedging the other tightly up against it. All the available neck material I have is laid on top of the planks to prevent them from flipping up due to clamping pressure. I use 5 minute epoxy for joining.

Once the (yes, you read it right) epoxy is dry, I cut out the viola form and proceed to thin the edges with the Safe-T planer, which is this wheel armed with sharp mowing blades underneath it. Having mounted the plane on a drill press and adjusted to a specific height, anything taller than my height setting is sheared off. Wonderful… the process creates a nice flat border around the fiddle in preparation for the purfling process.

unfortunately, the planks flipped up overnight, and now we have a strong glue line showing down the length of the back. if this was hide glue, we could undo the join and start all over again, but it's a little too late for this one. oh well... what the heck, I'm no Stradivarius. It's close enough for jazz, we're not saving lives here! On i go with the hollowing out of the back.

turning to Michael Darnton's website is always a help:
http://darntonviolins.com/viola.php

to be continued...