Catnip's (John K) Bench

[scordatura]

I should have said Addie. Was that who you meant by AD?

[catnip]

Yes,   I printed out his Kreisler form and a hi-res picture of the back.   Then scaled them both at Staples.. The form was scaled to ~347 mm and the back was scaled to ~354 mm...  Since Addie did the hard work to draw the form it saved me the trouble of using the back and subtracting 3.5 mm from edges and adjusting the corners which is the way I usually do it.  As far as I know Del Gesu used just 2 forms so I could have used the Cannone.  In any case what is the arching height of the back from the Keisler poster.??  .. I am assuming it would be close to 14.5 mm.   Also the Kreisler f-holes looks very much like a Strad.

[scordatura]

According to the Strad poster, the top is 15 mm and the back 14.5 mm. Yes the f holes are kind of Strad like. When I have played this instrument it has qualities of both a Strad and DG. 

[catnip]

The back is finished.  I have left it a bit heavy at 120 gm because I intend to do an overall cleanup after I set it up in the white.  It has good flexibility and a nice ring tone and is in the acceptable range for its density.  The garland at 59 gm is also a bit heavier than normal but also still acceptable.  Time to move on to the top and the scroll.

[catnip]

It has been awhile since I had time to get back to this violin.   Just finishing the top at 65 gm with BB with mode 5 at 345 hz.   Next step is the scroll.

 

[J.DiLisio]

I'm enjoying seeing this come together. Thanks for sharing!
What is the M5 of the back if you don't mind me asking?

[catnip]

The back was left a bit heavy at 120 gm with M5 at 358 hz.  I do not tune to a specific frequency, rather I just record the mass and M5 to obtain a stiffness factor for future reference.  Almost finished the scroll ... it is not a copy of the Kreisler scroll but rather my own consistent style.

[jezzupe]

looking good man

[catnip]

Slowly getting there.

 

 

 

 

 

[catnip]

Now it is time to set the neck.  Since my neck root is ~ 86 degrees the mortise will deeper at the heel (5.5 mm) and shallower at the top ( 3.5mm)... roughly a 2 mm difference to get the correct projection.  I use the edge overhang as a guide to cut the mortise with a small veneer saw but it does not reach all the way to the button which must be finished with a knife (as shown)

 

 

[catnip]

I finished the violin about 2 weeks ago and thought I would try out a set of Alice 708 (silver, aluminum, nylon core strings) with your choice of a  wire-wound E or plain E.  The G and D strings were very good but the A and E were a bit weak even after the strings settled in.  I replaced the strings with  Warchal Karneol which settled in very quickly and improved the overall tone.

I am just waiting for the weather to improve before I start varnishing.

 

 

 

[Thomas Coleman]

Looking good!  What varnish will you use?

[scordatura]

Nice progress. Does your Kreisler want to play Liebesfreud? Seriously, how does it sound sans varnish?

[catnip]

Back to the mahogany violin to color match the top to the mahogany.   I used sodium nitrite ~ 4% solution to "age" the spruce.  I dampened the top with water before applying the nitrite then applied some transparent ColorFx dyes using a mahogany formula which puts you in the ball park.  But because the mahogany had a very slight pink- purplish hue I needed to a drop or two of blue.  The main caution with color matching is to do it incrementally and go lighter than you think.  Also the "wet" color is not the same as the "dry" color.

[catnip]

Almost finished.  Just some very fine sanding to do and one final coat.   This is the natural color of the mahogany with just a ground coat with fumed silica to seal the pores followed by two coats of  "Vernici"  amber oil varnish.  After all the pictures posted here I thought I might try it out on these three violins.  I have been using Hammerl varnish with good success but with any varnish you have to know how to use it and what solvents and additives are necessary at the various stages.  Nunzio's varnish is much simpler to use and dries much faster and has more shine to it.

 

[catnip]

Here are the quilted maple and the mahogany together in the sun, and the final flamed maple hanging from the lilac bush after its first ground coat. 

 

 

[J.DiLisio]

Wow! that piece of mahogany really transformed in the varnishing process.

[Evan Smith]

That all  looks delicious,,

Great job of matching the top to the mahogany  back.

Thanks for the explanation on how you accomplished it.

[catnip]

The violins are all finished now and are being played in.  I have been busy with promised repairs over the past few weeks... rib shortening with end block replacement, fingerboard replacement  etc...

I will be starting a new build shortly but I was reading Lashof's book on violin making and mentions making a collapsible form using three pieces 4 mm aviation plywood for a total thickness of ~12 mm (or 1/2")   Aviation plywood costs an arm an a leg since it is not a standard size.  I decided  to use  three pieces of readily available plywood 6 mm, 3 mm and 3 mm for a total of ~ 12 mm.  From reading and re-reading his description it is a rather interesting method but I had to adapt it to my style where I like a longer and narrower end block.  If you use 50 mm wide blocks the build is much easier.  This is a method for makers that don't have access to tongue and groove router slot cutter.   This, for me was more a proof of concept.  The main point here is the form with removable top and bottom center pieces is made first then the pattern is cutout afterwards. Here are some pictures to explain the method

[catnip]

Well the summer repairs are over and it is back to making again.  I have been thinking of transferring my half-templates to collapsible forms.  I finally figured out a method that works and it is easy to produce a stock pile of collapsible forms using a 3mm slot cutter.  I will see how they work on my next few builds.   I am sure I will have to make some slight adjustments.  Here is one with center alignment pins and the other with off-center alignment pins.  I just use 1/2" flat head 10-24 screws and tap right in the wood after it has been harden with crazy glue.

[Urban Luthier]

cool looking form. curious to see how it works for you

[catnip]

A little more progress:   Blocks are in,  combination of willow and spruce.  I like to use a longer thinner end block and trim later as shown.  It gives a little more support for future chin rests.  I just finished my Kreisler model so I thought I would continue in the same style with a cannone model   (slightly adjusted).

[catnip]

I am going to build violins from flamed ash, maple and cherry.   I am saving the collapsible form for the another quilted maple.  Here is the garland with linings for the flamed ash.   The mahogany blocks weigh 33.6 gm and the ribs weigh 23.4 gm so I am predicting that the garland will come in just a bit over 50 gm + the linings (10 gm) after trimming.

 

[scordatura]

Nice lining clamps!

[catnip]

Working with the back on  outside arching, corners and overhang.