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Kae Han's bench


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10 hours ago, Nick Allen said:

We're all looking forward to see! 



10 hours ago, Jim Bress said:

Welcome to our crazy "family".  I'm looking forward to seeing your work.  What part of the world do call home?


Hi Nick, Hi Jim ,  nice to meet you!   I live in Taiwan.  I started violin making 3 years ago, mostly following Strobel'sbook  as well as Chris Johnson and Roy Courtnall's book. Videos on internet are valuable resource to me, though their procedures are differ from each other.  Among which, I like Davide Sora's works the most.  

Currently I'm working on my #5... My tools, techniques, procedures vary each time...because I'm still feeling out  my way.... 

-Kae Han

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Self taught, even with books and internet is a very different thing from schooling. It isn't easy.  But if you've made 4, then you have the passion for it.

It is a lot of fun to make instruments, and I think that passion has to be there, or they will be sterile.  They may be perfect and still be sterile.  Those who like perfection may not think so.

Welcome Kae. 

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On 8/7/2019 at 10:16 PM, Ken_N said:

Self taught, even with books and internet is a very different thing from schooling. It isn't easy.  But if you've made 4, then you have the passion for it.

It is a lot of fun to make instruments, and I think that passion has to be there, or they will be sterile.  They may be perfect and still be sterile.  Those who like perfection may not think so.

Welcome Kae. 

Hi Ken_N,

Thanks for your encouragement.  Passion I have. Perfection? There is a long way to go...I'm proud of myself to have the courage to start from zero, though.


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15 5/8 inches viola project

I'd like to start my thread with my opus #4, a 15 5/8 inches viola.  Why viola? There is a little story behind it...  I built this viola upon my dear daughter's request.  She had an urgent need of an viola for a  string quartet competition earlier this year. As the initiator of the string quartet at her school, she volunteered to play the viola part despite the fact that she had never played one before.  The worst parts was we didn't have one.  I suggested the possibility that I could made one for her, and my daughter put her trust in me.....    

...I made it just in time for their national final...and the young fellows did a real good job, too!   

Sound of my viola (in a string quartet)-


Mold and Rib Garland

This viola is based on Henry A. Strobel's model, as given in his book. 

My work procedures were mostly adopted from Chris Johnson and Roy Courtnall's book, Strobel, and resources from internet. Nothing much is new...   Just posting them as a log of my work, and sharing the joy of violin making with all of us.

I used a 12mm thick MDF to build the mould. Holes were drilled as on Strad's mould and space for clamps was also reserved. 

I used a block plan to trim the spruce blocks square and roughly to heights. There will be a slight slant toward the neck in rib height. I anticipated the rib height variation when preparing the blocks. Three screws were used to level the mold when gluing blocks to the mold.



Outline of the corner, upper, and lower bouts were scribed to the blocks with the help of an aluminum template.  C-bout blocks were cut to shape with a gouge and refined by round files. 



Ribs I acquired from supplier were just of enough length  to make a small viola. No room for mistake!  I got to be very careful not to crack them when preparing them. I planned the ribs roughly to the target thickness with a  toothed blade, and then smoothened them with a thick HSS scraper, thinning to the final thickness. For planning the sides, I prepared two pieces of pine padded with cork to hold the ribs upright.




A steal strap and wood block with curved sides were used for iron bending. I ran into some problems with the tight turn in the upper C. To avoid the risk of breaking them apart, I stopped struggling with the hot iron.  I decided to rely on the pressure from the counter form later in the glueing stage.



I intended to mimic the Strad's way of fixing C-bout, i.e. fixing the counter form with strings, but later I found it rather difficult to accomplish the job without lots of practice.  The belly and back sides got to be of equal tightness, and you have to do it quick enough before the glue set.  After several attempts, I decided to give up, and switched to plan-B, fixing it with clamps.  


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The clamp consists of a counter form on one side and a flat piece of wood on the other side. Notice that instead of a hole, an open slot was cut on the flat part. This makes life much easier. It allows a quick access.


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To me, linings are harder to deal with than ribs. I haven't broken a single piece of rib since opus #2, but I messed up with linings quite often. After the linings were all in place, I trimmed the rib height with a plan.  I than further smoothen the glueing surface on a big sand board, and did some fine adjustment on the height. 

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The next step would be tracing the rib outline to the plates... I'll leave it for the next post.

-to be continued





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18 hours ago, Thomas Coleman said:

Great photos Kae.  I really enjoy in-process photos.   There is always so much to learn.  Your work looks great as well.  Do you have photos of the finished viola?

Hi Thomas, I'm so happy that you enjoy the photos! Here are some photos of the finished viola.  I don't have my own varnish yet. On this viola I used OldWood System. The color of the instrument on the photos appears wormer than it actually is. 











Edited by Kae
Redundant photos
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15 5/8 inches viola project (-continued)

The maple and spruce plates were jointed and prepared in an earlier time  The rib garland was also ready as described in my earlier post.


Front and back outlines-

To drill holes for positioning pins on the plates and on the blocks, I clamped the rib to the plate, made pencil marks for upper and lower edges. I then remove the rib from plate, and drilled small holes about 4mm inside of the pencil lines. To drill holes on the blocks,  I clamped the rib back again and inserted the drill bid through the existing holes, and extended the holes into the blocks.  The existing holes on the plate served as jigs to guide the drill bid, so that I could get holes match that on the  plate.


Flipping the whole thing over, I could mark the rib outline onto the plate and draw the edge outline with the help of an appropriate sized washer. 



Now that the lines were drawn, the plates were ready to be sawed out.



It's always an enjoyable moment for me to see all the main parts being cut out in shapes......They were not chunks of wood anymore....



Arching and purfling  -

The cradle I built was made of layers of MDF.  It can be attached to a ball/socket mounting I bought from DICTUM. 



I started to do the initial thinning of the edge after the edge thickness was scribed on the side walls of the plate.



Preliminary arching thus followed...



Flat surface along the edge was prepared for purfling.  Since I had had problems with cutting purfling groves, I decided to cut the channel first, and it's important to leave enough thickness for future modification.  With the channel precut, I didn't have to cut too deep.



I used a double-bladed marker to scribe the purfling boundaries first...  



.... and cut the wall with both a right-beveled knife, and a left-beveled knife.  




The floor of the purfling channel was cleaned up with a narrow chisel....

......and it's time to purfle...



I gouged the channel  a little deeper so that fresh and clean purfling could be exposed. Then, I blended the channel to the arching and did some adjustments mainly by eye. 


.....Scraping.....  and fine modification of the shape....  This has been the step that I enjoy the most!



-To be continued


Edited by Kae
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15 5/8 inches viola project - (continued)

Jig for setting the neck

I saw this article written by Joseph Curtin in The Best of Trade Secrets 3 in which a jig for neck setting was described.

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Based on the same idea, I made mine for my 15 5/8 inches viola project

In Curtin's jig the "bridge" is held in place by a screw.  In mine, the "bridge" is held by a magnet. I can easily adjust the position of the bridge without using a screw driver. 

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The whole structure is made of MDF.  In my setup, a piece of wood, the "bridge", is attached to a supporting arm of adjustable length. There is a thin piece of steal glued to the back of the "bridge" and there is a magnet glued to the support.  

On the "bridge" one can mark the projection height and position of the central line.  This jig made life much easier for it allowed me to have a definite and stable reference point to aim at

I built this jig the day when I worked on the neck setting, and the result turned out pretty good. I will use it on my next instrument, too. 



( My jig was heavy enough and set there quite well so I didn't bother to use clamps.)


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15 5/8 inches viola project  (- continued)

Plate Graduation-

I used two Japanese Gouges for rough cuts. Contour lines were first scribed to the flat side of the front plate. Doing so allowed me to have a clear idea about where and how much to dig. I reduced the thickness of the central area first,  to  thickness which the contour line marked and then moved on to the adjacent contour line, removing wood in a larger region...  Contour line by contour line, I gradually reached the outer most contour and it was time to switch to finger plane for a finer job.



Thickness were monitored repeatedly and some brain energy got to be spared for those numbers to make sense.  Writing the number down on the plate was a good idea for me because I could make my brain cool and having a good sense about what's going on. 

For back plates I drew my thickness plan on its flat side and reduced plate to thickness accordingly.  I re-drew the thickness plane again and again whenever I felt confused. Measurement data were also marked in situ.  (However, measurement and writing the numbers down is time consuming so I decided to build a thickness punch for my next instrument.)

For final thickness,  I listened to the tap tone.  I would accept the result as long as the modes were in harmony with each other.  Why? I don't know. Just out of intuition, for violins are complicated anyway. Why not leave some room for freedom and imagination? 

F holes and base bar -

Four eyes were drilled first with an F-hold drill purchased from Dictum. I used cope saw for the rough cuts and a sharp knife to finish the job.  Practice makes perfect. I finished the f-holes without relying on files or sand sticks this time.  My fluting was done after the f-holes were cut.





I had been sloppy on my first three instruments when fitting the base-bar.  It was the first time that I glued these little blocks of wood to help base bar fitting.  With the blocks glued on,  I got the work done efficiently for I was able to have a definite reference for location and orientation.  


And now it's time to remove the mold from the rib garland......

After some struggle, I safely removed the mode from the rib garland. .......    What an exciting moment to see all the parts ready!


Closing the sound box-

I used nails as locating pins  when I glued the plates to the rib.  Then,  I removed the pins and plugged the holes with wood plugs, maple for the back and spruce for the front. I usually don't let the plugs go too deep into the block. 







-to be continued


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15 5/8 inches viola project (-continued)

Scroll, pegbox and neck-


This was the 4th scroll I had carved and I was quite happy with my fluency in processing and improved knife handling skills :).  



This was the first time that I glued some little pieces of wood to assist alining the fingerboard to the scroll. (Skills I learned from Davide Sora's video.) Thanks to Davide!  I used to shape the neck before gluing the fingerboard on.  This time I did it the other way around. Plus Davide's alignment method, the fingerboard was able to have an orientation consistent with that of scroll.   The neck was then trimmed to width and further shaped, so were the chin and neck foot. 

I made oversized neck foot, and would trim it to size and proper shape after it was glued to the box.   I shifted up and down the neck with my left hand not only to check for smoothness but also testing for good playability.  Sometimes I felt an urge from inside of my heart to take bold actions in shaping the neck and neck foot.  Lucky enough, it always turned out to agree with the shape given by the neck templets.  With some scraping, the neck looked like a descent neck now.  And it's ready to be fit to the resonant box......






-to be continued 



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15 5/8 inches viola project (-continued)

Setting the neck-

At this stage, all the wood works were about coming to an end.  The only thing left was to put the parts together; however, it's not so easy a job. Sigh....

Neck setting is the most difficult part of violin making as far as wood working is concerned. All the requirements on neck length, over stand, projection, and alignment are to be met in a snug fit mortice junction.   Lucky enough,  I did a fairly good job this time but still were not comfortable with this difficult task.

From earlier experience with my #3,#2, and #1, the mortice tends to be wider then expected if I naively cut along the pencil line transferred from the back of neck foot.  To prevent this from happing, I took the measure from place 2mm below the actual level. For the bottom of the neck foot, I did some  math and extrapolate for the width 2mm below the bottom.  The results turned to be a good fit :P....   Perhaps next time I should leave some safety margin. 



Alignment and projection were done with the help of a jig I made (described in my earlier post). My jig held the "bridge" stably in position so that I was able to have  a reliable reference to target at.  

After some struggle, .....the measures were met!


Dry fit-



Glue -



.......almost done   ......... 


.....couldn't wait to hear its sound....:)


-to be continued

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  • 2 weeks later...

15 5/8 inches viola project (-continued)

Fitting and test drive-

I strung up the unvarnished viola on last Christmas eve.  At that time, I didn't have a viola bow yet, and I played it with a heavy violin bow in stead.  How did it sound?  I would say not bad! :lol:







On this viola I used commercial products- OldWood varnish and ground .  

Casein/borax solution was first applied to size the wood. It swelled the grains so I scrapped it down and applied once more.  



I must have scrapped too much after casein sizing and the spruce apparently absorbed too much ground liquid (OldWood A/B fluid).



OldWood refractive ground as the 1st layer followed by 2 layers of clear varnish, one layer of colored varnish, and 2 layers of clear varnish. No rubbing between layers ( for I had to get everything done before my daughter's string quartet competition ).





....  layer by layer,  in and out the UV box  ....

... and  its done!




The Music Competition-

This viola came out of the UV box just in time for my daughter's rehearsals and the national final this March. She played this viola in the  competition, and her quartet won the first prize.  So my job was done!








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  • 4 weeks later...

Recent I started to work on repairing some old student instrument.  It more fun then I had expected,  and changed the way I look at a violin making somehow....   Wood work part is ok for me.   The next challenge is retouching....

First time edge doubling job and End pin bushing


Flattened ...


...with a new head block.



End pin bushing

I made the cone myself with plane maple.



Drill guide hole.



Rimming and done!



First daring repairing job of mine.     Not bad for the first try!       :)   


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