Catnip's (John K) Bench

[catnip]

       As this summer comes to an end there is nothing on the bench other than one violin that is drying in the sun after varnishing.  But I will be starting a new violin back from a gorgeous piece of wood that has been aging for several years. I have been collecting wood for the past 15 years and I have never seen such figure in wood.  I have a paper template that I can move around which allows me select which part of the board will give the best figure.  I purposely have not identified the wood because I don't think it has ever been used for a violin.   You are allowed to guess what it is.

[Wood Butcher]

Mahogany?

[catnip]

You guessed it!   Used a lot for guitars

[Guest]

Nice wood John! 

I'm also planning to build a five string from some Honduran Mahogany I have... rings like a bell. I hope you post some photos here on your bench when you start. Will it be a 5 string?  What will you use for a neck?

[catnip]

For the neck I plan to use some quartered Caro-Walnut (gun stock) that I have that closely matches the look and feel of this piece .

[catnip]

I decided to make a new mold for this violin based on the 1709  Viotti.   I did some research in my books and files and found that I have two different Viotti.  One from 1709 based on the G form ( thanks Addie) and has a one piece back; the other from 1718, also known as "Arnold Rose" has a two piece back and is smaller.

 For this mold I printed out the image from UK_RAM website on 11" x 14" paper and took it to Staples and enlarged it to 358 mm on 11" x 17" paper.  Split it down the middle and took the right half as my template.  Spray glued it to 1/8" Baltic plywood and cut and sanded to the outline.

Then reduced the outline by 3.7 mm (which is to outside of the purfling line) and further reduced to corners by 2 mm.   I taped this template to 2 pieces of 1/2" Baltic plywood  and rough cut the outline on the bandsaw. 

I taped all the pieces together and using a router trim bit finished the outline exactly so that length was 358 mm with half widths of 80.8 / 51.8/ 100.5.  This will give me  the approx  desired width ( UB/ CB/ LB)   of  161 / 103 / 201  mm

Now its just a matter of gluing the two halves together and marking with drill holes where the cutouts will be. Here the form is glued with the half template.   Note: this method does not use centered guide pins.   The locating pins are in the upper and lower bouts shown a green circled dots.  

Its almost done.  I just have to drill out the large clamping hole, varnish and label the form.

I learned this quick method from article S. Ovington wrote.   It takes roughly about 3 hours to make a new form with two coffee breaks.

[catnip]

Here is the finished form

[Jim Bress]

Nice. I like your labeling of demensions. Is the lower bout with correct?

-Jim 

[catnip]

I number the blocks from from #1 to #6 and include the approx. block heights.  Those other dimensions are for rib lengths and (lining lengths).   I use block numbers as a reference when I cut the ribs so that I don't flip the grain pattern which is easy to do.   I also sequentially number the ribs as I rip them from the stock so that I can  use the best sequential pair for grain matching at the end block

[Jim Bress]

Oh ok. Sounds like a good system for limiting waste. 

[catnip]

Ribs and linings  installed.  Looking forward to carving the back now.

[Nick Allen]

2 hours ago, catnip said:

Ribs and linings  installed.  Looking forward to carving the back now.

You make those clamps?

[Nick Allen]

2 hours ago, catnip said:

Ribs and linings  installed.  Looking forward to carving the back now.

You make those clamps?

[FoxMitchell]

Fanciest lining clamps I've ever seen!  

[catnip]

Yes, I made them.   I never liked the clothes pegs with extra elastics, since you can only do one side at a time.  I tried some cheap plastic G clamps but it was easy to strip the threads. 

 

Then I made some wooden G clamps but sometimes (not often) the leg of the clamp would break.  So finally I found some aluminum C channel and added the little plastic insert. These clamps work really well for me.

 

[Nick Allen]

1 hour ago, catnip said:

Yes, I made them.   I never liked the clothes pegs with extra elastics, since you can only do one side at a time.  I tried some cheap plastic G clamps but it was easy to strip the threads. 

 

Then I made some wooden G clamps but sometimes (not often) the leg of the clamp would break.  So finally I found some aluminum C channel and added the little plastic insert. These clamps work really well for me.

 

Those are really neat little guys. 

[catnip]

Rough outside arching done.  I have just finalized the overhang by temporarily gluing the back to the form.  Tomorrow I will remove the top,  finalize the edge ledge and then start on the purfling.   This mahogany was pretty chippy under the small finger planes because of the figure.

[catnip]

The purfling edge (ledge) has been finalized to 4 mm for the most part.  I leave the button a little thicker (4.2 mm) and the corners at 4.5 mm.

[catnip]

Purfling groove laid out and cut.  Corners finished and purfling glued.

Outside longitudinal and cross archings almost completed.   I like to revisit the arching over a few days with a fresh eyes.  The plate weighs 275 gm at just under 16 mm.  The next step is to do the inside graduations.

 

[catnip]

Took a two week break to redo the front steps.  I still have to re-install the railings but I needed to have functional steps as soon as possible.  The previous steps were destroyed by carpenter ants which I have addressed with some home recipes of borax and sugar.  Each stringer was custom fit to the ground with a template with a hinged bottom then planed to fit using a cardboard test strip. 

Looking forward to getting back to working on violins.

[Guest]

Is this mahogany fiddle going to be a 4 or 5 string? Please continue posting photos and especially a sound sample when completed. I'm very interested in your project and making a 5 string from my mahogany stash.

[catnip]

I finally finished my front steps and now I can get back to the mahogany violin.   This will be a regular 4 string violin.   I have made three 5 String violins.

[FoxMitchell]

48 minutes ago, catnip said:

I finally finished my front steps and now I can get back to the mahogany violin.   This will be a regular 4 string violin.   I have made three 5 String violins.

Pretty!

 

On 9/17/2018 at 11:13 AM, catnip said:

Purfling groove laid out and cut.  Corners finished and purfling glued.

What glue did you use here?

[catnip]

I decided to take a picture before I started gluing to document the process.   Using this method there is no time to take pictures.  You have to work quickly because the hot glue will swell the groove.   There are other methods to glue purfling but this is the method I am most comfortable with.   It is fast and efficient.   I also compress the purfling using a homemade press similar to what Peter Westerlund uses.

[Rue]

Love the new stairs!