Urban Luthier

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Posts posted by Urban Luthier

  1. 2 hours ago, Jim Bress said:

      A portable hepa filter unit will probably be sufficient for a clean room.  May also be all that's needed in Chris's shop.

    Like Ken I've been having sinus trouble from the dust kicked up from planing and sawing. A better N95 respirator has done wonders. 

    A combo of a good shop vac, portable help filter and window fan may do it for me. 

  2. thanks everyone! 

    Box Fan is a good idea and cheep -- could be hooked up to a timer also. I looked at the Festool products, thanks for the tip. They seem to be more for capturing dust at the source from power tools. Well made but expensive

    I like the idea of the overhead units as they seem to have quite deep filters. Any issue with putting it on a self on its side as long as there is free space around it?

  3. I have a very small shop 8 x 8ft with ceiling height of 6.5 ft! I don't have any power tools in the shop but I do most rib re sawing and flatting by hand. Saws and toothing blades kick up a moderate amount of dust. 

    I'm looking for an efficient way to filter dust. I came across a compact air filtration system  on Amazon. I can't mount it on the ceiling because of hight but I could put it on its side on an open self with enough clearance

    Any experience with these? Other suggestions?

    Thanks in advance




  4. It has been a while since I posted, but a PM from Jim motivated me to take some photos of current work. I started a cello based on the Davidov / Gore booth. I drew it up by hand based on Roger's poster. (There is a photo of the Gore booth with the belly off the body which was useful as well). 

    The form is two 18mm baltic birch plywood sheets laminated together - I was inspired by a from by Michael Koeberling posted in his bench. This was a lot of work to make but it is quite light weight and easy to maneuver.  

    I don't have a bandsaw capable of re-sawing cello rib stock so I ripped 3mm pieces by hand using a Japanese Ryoba saw. Great saw, tracks well but this was a lot of work.

    The cello wood I have is attractive enough but certainly not stellar. Still it should serve well for this project






  5. 2 minutes ago, David Burgess said:

    That looks like a really viable, convenient, and inexpensive option. Whether a static charge builds up in the plastic reflictive film, attracting dust, I do not know, having never tested it. If it does, it could be either advantageous, or a detriment.

    Humm good point David, never actually thought about that. I can say I used one of these on my last instrument and I had no issues at all with dust. In fact this is the only instrument I've mad where i didn't have to polish the top coat to get rid of dust zits. 

    Next time I set it up i'll test for static and report back

  6. Hi Jim for what it is worth i used 108mm in the upper and 110mm in the lower. Why? because that's the aprox measurement in the Sacconi drawing of his B form reconstruction.  I wouldn't go any wider as it is hard to find good willow from luthier suppliers that is milled more than 115mm. Figure i can always trim them back if need be.


  7. 1 hour ago, David Burgess said:

    I don't use a Strad viola model. What I use is more like an enlarged Strad violin.

    So why didn't Strad think of that? Perhaps he did? My theory is that he scaled up a long pattern violin (the CV design was done around the same time as the long form violins were being made). Then later modified the CV form by flatting the curves of the top and bottom to give a slightly more boxy look we see in the MacDonald and Cassiveti, Paganini

    Who knows what the strad shop would have come up with if they actually redesigned the viola form in the golden period. I did a quick scale of a golden period Strad violin in a CAD app and came up with UB 193 Middle 132 and LB 242 on a 413mm body. Quite a bit different than the CV form!

  8. Interesting to chart the progression of Strads violas -- The Mahler is an outlier -- the only one of its kind we know of. The CV form followed and the early violas on this form -- the Archinto in the RAM and the Tuscan in the Library of congress are a little longer (and rounder at the top and bottom than the later violas like the Cassevetti and MacDonald. It is possible the CV form was cut down at a later point (flattened a few mm at  the top and bottom block). Here is an overlay of the Archinto outline from the Strad poster and Addies tracing of the CV form --

    Screen Shot 2019-09-10 at 10.32.55 PM.png

    Screen Shot 2019-09-10 at 10.33.27 PM.png

  9. 1 hour ago, Húslař said:

    Violas from A.Stradivari´s workshop are really beauty!

    Thanks for photos - have you more photos of Tenor Medici? (I am interested in varnish of this viola on last days - most important Strad in this case)

    stunning to see it in person (but you have to go to Florence and skip by the David ;) Good photos in the B&G strad varnish book and the S&Z Tuscan violin book

  10. 3 hours ago, A432 said:

    Soloists who could afford Strads avoid them, it seems.

    I don't believe there are any soloists around today that could afford a Strad Viola. Peter Schidlof seem to do just fine on the MacDonald and (although he had troubles to begin with) Antoine Tamesit sounds just fantastic with the Mahler.

  11. I think the sad truth is Nathan that professional woodworking, for the most part, now is practiced by a small number of professionals and amateur enthusiasts. 50 years ago most schools taught woodworking and households would have has basic wood working tools. Fast forward to day and I'd guess that most homes don't have basic carpentry tools.  Although the current production Lee valley (veritas) and Lie Nielsen are made to much higher tolerances than Stanley's of old, there is no denying that it simply costs more to manufacture product for a smaller audience. 


  12. On 9/7/2019 at 6:54 PM, JavierPortero said:

    For some reason Stradivari violas are not regarded as model instruments, 

    Point of view started by the Hills and repeated over and over perhaps? 

    I've made a couple of violas on the Strad CV form (baroque and modern) that have turned out quite well from a tonal perspective. 

    The Mahler looks interesting too - there is a new and wonderful recording from Tamestit playing transcriptions of the Bach Gamba sonatas. Sounds wonderful 


  13. HI Jim

    I have made some progress. I was all set to go for the P.G. Rogeri cello based on the poster published by the Strad. I even drew the outline up in CAD (I did increase the length by 5 mm at the top to give it a slightly rounder (and increase the stop length to something more modern). See below. I have the Rogeri template in PDF  - just PM me if you want it

    I did a 180 at the last minute and decided to go with something more conventional - a Strad B from based off the Gore Booth and Davidov. I haven't made a cello before and there are a ton of strad related resources available to help along the way. I drew this one up by hand.

    Below is the 'work in progress' form I made for the strad b - double thickness baltic birch ply. A ginormous pain in the you know what to make.

    Screen Shot 2019-09-02 at 1.51.18 PM.png


  14. On 7/14/2018 at 1:23 PM, not telling said:

    But at this higher temperature, wouldn't you get something more like stand oil?  It can get so frustrating to wade through the information. All I want is to know how to make the oil siccative. Vernici Liuteria, what is the difference between boiled and stand oil? Time?

    What Jon says above will make linseed oil dry more quickly.  You can also sun, thicken but it takes longer. It easy to test the drying properties of oil. simply put a dab on a piece of glass or plastic and leave in a window. 

    Re varnish making, I feel we needlessly cycle here so often on issues, workflow and sound practice that has been so well documented in the forum.

    The bass book says most of what we need for a practical workflow, Neil Ertz shared a wealth of info. Freds posts continue to  enlighten.