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HoGo

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  1. Too late. Don't you know the biggest factory in Luby (former Schonbach) in Czech republic was called "Cremona" Luby. They churned thousands or even millions of cheap fiddles a year from 50's till 90's...
  2. The old texts mention spirits of wine that has been rectified(distilled) at least four times... that can get you above 90%. I buy anhydrous ethanol dirt cheap, like 3 Euro per liter. Sold as fuel (bioethanol) denatured only by traces of bitrex. I consulted with the producer and it is above 99.9% ethanol (in the final denatured product). Best stuff ever for dissolving shellac for french polish. I've got a bottle of pharmacy grade ethanol and that is 96%.
  3. In my experiments I followed information I collected from various papers. Basicly I baked for an hour or so at 100+C to get rid of most water then immediately packed the wood into thick aluminum foil with as little air trapped as possible (of course there is some air/oxygen in te wood but it didn't affect the results - the goal is not to burn the wood) I packed it well and sealed with aluminum tape (heat resistant). Then I baked it at 160-170C for few hours (first samples for 4 hours, the real wood for a few more) and let it cool slowly for a day or so. Then opened the packing and let the wood sit for few days. I weighed the wood to find out when it reaches equilibrium. Without the aluminum foil the wood would burn or at least darken to dark brown color. There was no problem with steam coming from wood so no need for vacuum. But this is different from "wet" process as te water surely causes some hydrolysis and other changes in wood that the dry process does not.
  4. I don't know about violin players but there are more than just a few top level mandolin players who are lefty and play righty. Chris Thile being one of them.
  5. CT is reliable but problem usually is somewhere between the screen and seat. There are various CT scaners, the modern micro CT are extremely precise (but expensive), the old common CT's are nowhere near that, something like 0.5 to 1 mm voxel size. You can approximate a lot even from such fuzzy data but the operator must know what he is doing.
  6. Are you using some professional pressure cooker? 170C steam is at about 9 BAR pressure, that is not that much, many common pressure chambers for steam bending wood can handle that. Of course DIY units made of PVC pipes or such can explode and cook someone alive. I've done some "baking" of wood but without steam in oxygen free environment. I did measure density only.
  7. CT scan is fuzzy voxelized object and the density is calculated by the sw for each voxel (color darkness is proportionate to density but the machine must be well calibrated with samples of known density) the edge voxels may be half air - half wood and their calculated density will be distorted. If those voxels are included in the final calculation, the average will be too low.
  8. Doesn't potash and alum generally desctribe the same thing? Potassium aluminium sulfate?
  9. I just can't see any bending problems with violin ribs that are 1mm thick. I bend mandolin curly maple ribs at 2mm+ thickness and some of the bends are just as severe as violin c bouts. Takes helluva patience to bend smoothly. One problem may be with maple that has "runout". Runout combined with heavy curl will make some parts really splitty. I would recomment using sanding belt as backing strap for those and bend slow and almost dry, it keeps the outer parts of end with less tension than using steel strap.
  10. No, it comes with free internet expert opinon :-)
  11. Big Brother (Google) watches you and wants to know who browses their web :-) That should be safe, but I personally never follow these links.
  12. If you use clamps you can plane dead flat. But tiny gap in the center can help keeping the ends closed when center clamp is tightened first and the end clamps added after that. I experimented with clamping order and even when the dry wood mated perfectly when dry clamped on one end only, after rubbing the joint with glue and end clamp added the other end opened visibly presumably because the added moisture. So I prefer application of two clamps simultaneously on both ends and then add third in the center. If you intend to use rubbed joint with no clamps you'd better plane some hollow into the joint.
  13. That is certainly reaction wood (called compression on softwoods). I've played number of flat top guitars made with wood that had much wider bands of compression wood than yours and they played nice... but on flat top with the heavy bracing, bridge plate and bridge glued to top, the top makes much smaller part of the whole. I've got one mandolin top carved out of reaction spruce firewood. I'm not sure I will use it, but once I have a scrap back to match I will certainly give it a go.
  14. Spirit of wine is old name for alcohol (ethanol). You see it all the time in historic texts. Look for molecular sieve. You can get it up to to 99.9%. But it's better to begin with high percentage.
  15. When I made buffalo horn picks I polished them just like plastic, I used progressively finer sandpapers (wet sanding, up to 2000-3000 grit) and finished with car polish (grey 3M paste I used to polish up some fine scratches on my car, it contains no wax, just fine abrasive, or I would suggest using Novus or similar lacquer polish).
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