HoGo

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  1. Well, in my situation back then it was either you make it yourself or you don't have it... And with a bit of luck to know some skilled friends to help with some steps (the welding was done by my firend, my welding skills suck). Living behind iron curtain (or still shortly after it fell) had at least some positive effects... todays folks just go and buy whatever they want...
  2. I made my own compressor almost 20 years ago, being student with no income and every luthier supply was imported (meaning extremely expensive) I had to make almost all my tools. I remember how I cringed when I bought the switch, pressure valve and trap for unheard amount of money (something like $50) but the rest was pretty much free... together with one afternoon of work... Two old refrigerator compressors, one (not working) cut open and emptied to make a tank and other wired and connected with hoses together and mounted on a piece of plywood. After first try I learned I need to add valve to release pressure between the compressor and tank or the compressor won't start against pressure over 3-4 bars (I set it to start at 4 and stop filling at 8). There are pressure controller switches with built in valve for relieveing pressure, but I failed to know that, but somehow managed to retrofit the switch with old bicycle valve (schrader) that releases pressure when lever inside the switch moves and touches the pin and it had worked well ever since. you can hardly hear it running... I've always wanted to build some casing to look more professional, but never had the time...
  3. Most of you seem to be repeating the idea that total mass is most important factor... but wouldn't a position of center of gravity make difference? Like tailpiece that has most of its mass near bridge vs. one that has more mass near tailgut and less towards bridge but the total mass remains the same?
  4. I've never heard of ponding as way of drying wood. I've always thought of it as fungus prevention before the logs are cut. What's the theory behind it?
  5. I'm not sure about how much water it will hold and not release back into wood upon drying out (especially at elevated temperatures), kinda like distillation... Also the alcohol evaporation rate would be likely quite high and wood drying pretty fast from outside towards inside possibly causing really huge stresses within the wood (the stresses that are avoided by sealing endgrain and drying relatively slowly after the free water is out i.e. approx 30% MC) I've read about kilning techniques involving saturation with hot oil that will cook the water out while preventing stresses, the harder part was removal of the oil using various methods being able to re-use the oil for the next wood. (also the alcohol could be possibly reused) There are some modern methods that are unbelievably fast and produce lumber superior to lumber dried with ordinary methods meaning less cracking and internal stresses induced by drying. One study mentioned world record of drying defect-free 10x10 cm oak beam in few hours from freshly cut (my memory suggests 2-3 hours). But all this is mostly in experimental labs as traditional air drying or common kilns are just much more cost effective, the only downside is some time and space for all the stacked wood.
  6. I don't know possible value but if it's not worth full pro restoration at least it looks like it could be good project for a beginning violinmaker or student at VM school... All parts are there and it would provide good base for basic repair techniques of cello and likely result in decent student cello for sale. I see similar "packages" sold on ebay.... If I had lust for cello I would take it.
  7. Both Side views are distorted. Both were taken with camera roughly level with upper bouts or even neck heel. That makes the lower end obscured by the lower bouts (you can barely see the endpins). Also the ribs of widest parts were closer to camera than ribs near neck or in waist, and even if pic was taken from large distance (at least 4-5 meters) the distortion can be in millimeters. Your best bet would be looking at tailgut as the end of plate and resize to that length. The only (relatively) reliable measurement of rib height woyld be at neck and perhaps near tailpiece. Measurements from waist would be inflated and moreso the upper and lower bouts.
  8. Flat sawn will split even easier. That split direction is exactly the direction how you split your firewood...
  9. I wonder if all the fancy machinery is really needed to get the tongue replacement done? Looks liek slight overkill IMO. I can imagine good old school guy cutting the groove with gouges and files and chalk fitting new piece of ebony before the machinist quenches his router bit. (I can see new man against machine contest...)
  10. I wouldn't call it master grade with that stain but it is likely structurally sound except that small spalted edge. You can bleach that stain using hydrogen peroxide (>30%) after carving. I've done that on some backs that had that blue/green stains in the past.
  11. OP says the strings were still under full tension after the scroll was broken off so all the stress goes towards the undamaged part of head. So all it needs is good gluing job with whatever glue one is familiar with and can get reliable tight joint. Most violin folks don't use epoxy as much as HHG and I prefer it as well for instrument repair. I know strengths of epoxy and used it several times on broken stocks of biathlon rifles where HHG would look nice but probably wouldn't hold for too long.
  12. The main problem with Epoxy it's nearly impossible to get invisible glue line. With HHG it is quite the norm on clean fitting surfaces. Epoxy is thick and almost impossible to squeeze out of such ragged crack. And most epoxies REQUIRE some thickness of the joint for mximum strength. You can use strong fresh HHG and just hold it in place for couple minutes till the glue grabs and use two small clamps though the D string tuner hole to hold the scroll in place till the glue dries keeping the bass with scroll over the joint during the drying.
  13. I don't think there will be high stress in the joint. It's right through the last hole and mechanic gears don't apply pressure like tapered pegs do, they will just bear on one side of the hole facing nut so no direct stress on the joint. The surface of break is clean and jagged whch will lock well during gluing and provide adequate surface. I would go for regular hide glue and clamp with shaped blocks as needed. I would be aware of application of the screw right through the break - I would pre-drill the hole while the clamps are still on or I would drill out 1/8" or so hole almost all the way through the side and insert some soft wood dowel (basswood or such) for the screw to hold in (but would pre-drill small hole anyway). Now I see that the break is quite angled where the screw hole is visible so what I would re-consider what I wrote above. Perhaps it would not be needed at all.
  14. I agree with rapid change from wet to dry. My own experience was when I bought new dehumidifier for my shop. I had been without dehumidifier for some time and humidity stayed somewhere in 60-65% and when I got the unit I just turned it on and set it close to max (it didn't have hygrostat with display, just simple turn knob) thinking I will check the humidity in the next morning and set it more carefully. Since my shop is very small and the dehumidifier was quite effective I found the humidity went from 60's down to 20% overnight and back center-joint of one of my freshly finished instruments opened on 2" at tailblock. I managed to massage thinned hide glue into the crack and it pretty much closed itself from the humidity of glue and stayed closed for a decade or so till the instrument got stolen from it's owner. I really measure humidity very carefully since that day.
  15. Viola? Which of the woods burns longer? :-) I think the difference between wood of european willows and poplars can be really small. Often it is hard to distinguish which as used. I personally would be tempted to use some nice curly aspen I've seen. I've also seen nice curly goat willow (salix caprea) trees close to my home.