Geoff-UK

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About Geoff-UK

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  • Birthday 08/07/1950

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    http://www.richingsviolins.co.uk
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  1. Probably more important to have access to the opinions of some very good players - rather than makers. Geoff.
  2. Raw umber arists acrylic tube paint - mixed with some Ivory black pigment. Dries lightning fast - very opaque and very matt. Adjust the colour according to how much ivory black. Same for f holes and stock ends. Lately I have been varnishing the inner sides of the pegbox - and only blackening the base and nut end, feathered up slightly. Geoff
  3. Agreed - but there are often wildly differing prices for the same make tool - greed. It does not hurt to shop around. Geoff
  4. Cheapest I've found are at Madinter - 50 euro cello 1:25 - spiral cut. madinter Geoff
  5. Natural wear is ok - but actually modern cases can leave leave very unatural marks on instruments when the varnish is a bit soft and prone to marking on contact. I think its very easy to make a soft and fragile varnish - I've spent all my time trying to toughen it up ! 'Just' enough to survive case and shoulder rests - but not too much, is the quest I suppose. Difficult balance to achieve - given the timespan involved with judging ones results ! Geoff
  6. I did say white spirit mixed with Spike oil. On its own it realy safe, as you say - even with very fresh oil varnish. Spike oil is very agressive to oil varnish. Geoff
  7. A little bit of spike oil mixed with white spirit will often re-dissolve dried oil varnish in quite a controlled way. Not sure it will work with Hammerl though. Geoff
  8. Philip If you add some lime - I use calcium hydroxide - you raise the melting point of the rosin. In a back yard style set up though - as opposed to carefully controlled conditions, its a bit hit and miss - as the temps needed to fully react lime with rosin are up around 280 c. I've had good results with 5 gms lime to 100 gms rosin - cooked at about 210 c in the rosin for about 40 mins - then about 220 c with the oil added for about the same time. Keep your working process as similar as you can batch to batch. I'm experimenting with rosin limed with water added - and cooked at low temps, ie 180c max. It gives a rosin thats too hard really - but you can process rosin like this in advance - then add a proportion of the limed rosin to raw rosin. This is more controllable using simple cooking methods. Credit to tips from Joe - and a fair bit of searching online into commercial paint processes - which gleaned a few ideas. Not very scientific I'm afraid - but they never would buy me that chemistry set when I was a kid - so now I get my own back ! Geoff
  9. I'd say a violin can alter with age - but just as likely a good one could get worse or a bad one get better - or just a change in tonal colour. Likely culprits - wood and varnish. Thats playing safe - theres not much else there except wood and varnish ! Geoff
  10. The Guad 1785 Viola poster I've just used to make a mould is way off - and its not just a scale issue. The uppers and lowers are 2mm light - but the middle and length is accurate - comparing the outline drawing to the cited dims ( taken with calipers ) If the dimensions are given as marked with calipers - then check the drawing out and try to adjust things. They need to be used as a rough guide - its all they are. The original Guad is all over the place anyway - so it hardly matters. Geoff
  11. Maybe why Strad got all his mitres wrong - couldn't see ! Geoff
  12. I didn't mean to imply I get uneven overhangs - just the top plate may be distorted from the mould shape. You have no overhangs to worry about purfling after closing up - so long as you have enough spare of course. I generally trim the plate edge by eye outside of the scribed line before closing up - and that usually gives me a 3mm rough overhang minimum before trimming - if I don't get carried away. I leave more around the corners. One problem I find is you have to be careful of how you place your ff holes - as the c bouts and corners are a rough size until the final overhang is established - and you need to cut the ff's before that. Maybe why ff holes were marked out on the inside of the plate - you can work from your scribed lines of the rib outline. I'd really like to make some sort of caliper - that would go over the top when its located on the ribs with the two pins - and mark a centre between rib to rib onto the top. I generally I just make sure whatever I have rough over the scribed line is equal either side - before marking the centre of each bout. Or, I should try setting the ff hole eyes from the inside - maybe something to try out ? I find it quite quick to chamfer the inside edge of plate - so don't bother before closing up. Geoff
  13. I only make a template of the mould outline - which also serves as corner rib templates. I usually do a whole template as I router my mould forms from the pattern using a following cutter. I don't attempt to make this contra-facimile, as I flip it over to suit. The back plate outline follows that pretty close as its marked with ribs still on the mould. The top is marked from the rib outline as made up on the back. Its final shape is determined by the overhang to the ribs - which I do once the box is closed up - then purfle up and finish the sinking and edgework. The back and ribs is sometimes made up for a month or so before I do the top - and they can distort a bit. That does not bother me at all. Geoff
  14. Geoff-UK

    Back Graduation...

    Ernie - you only mention the thickness at the max. What's your thickness for the rest of the plate ? The Bergonzi I'm doing at the moment is about 5.1 central spot - but around the arc of the corners its down to 3.5 or so and in the bouts anything between 2.1 and 2.7. I mostly go on weight - and try to get around 100 -110 gms. No idea why ! Geoff
  15. The latest 'Bergonzi model' violin about ready for its neck set - and the last cello, a Guadagnini model in Poplar, finally 'off the bench' at last ! Geoff berg-top-corners by Geoff Richings, on Flickr - guad-body2 by Geoff Richings, on Flickr