uncle duke

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  1. plate tuning specs ?

    If you have a good ear and don't happen to be tone deaf then a safe way can be to use the online frequency generator by Szynalksi. It is not the best way but it is a safe way. I mention not being tone deaf because you will need to be able to pick out the generated tone that matches the tone of your plate when you think you're getting close to where you think you need to be or really anywhere during the carving process. You may as well get a scale that reads grams for weighing - one of those $15.00 or so digital scales from Walmart will work for violin. Arching height, shape and edge work should be given higher priority than just searching for the hz of your work and possibly the weight, though paying attention to weight while removing unneeded wood will get you to where you need to be quicker. You'll notice when you see the orange colored screen at the tone generator website that the number 440 hz is present. Take any piece of wood and try to see if that wood rings higher than that 440 hz tone or lower. Next use the arrows to raise the tone or lower the tone to match the tone of the wood you have in hand. Find pictures showing how to hold a piece of wood for checking it's ring tone. What I do is turn the generator volume down to 2% or 3% and put on headphones over one ear and leave the other ear uncovered so that I can hear the wood being knocked on. Don't leave the tone generator sound at 100% volume using headphones. This method is a different type of testing that what you see with others who use the computer, speaker and sawdust. glitter etc, for viewing vibration of open plates but will get you close to where you need to be to get better help from some of the better makers here at Maestronet - you just gotta catch them at the right time for help.
  2. French Polish materials

    Soft rubbing can be accomplished with either french polish alone or a mixture of polish 60% and spirit varnish 40%. Most available spirit varnishes are a relatively low grade finish and are used in conjunction with shellac. Spirit varnish improves the build of the polish and imparts a higher shine to the finish whereas shellac improves the durability of the varnish giving it greater flexibility and reducing it's tendency to scratch white. Manual also says the initial sealer coat will always look somewhat streaky and no attempt should be made to even it up by brushing the polish out in the way you would with house paint {brush}. Because the polish is very thin in body it dries very quickly. It should be simply laid on and allowed to dry. Drying time for a coat of polish is around fifteen minutes. If you choose to spray instead of brush or cotton/rag then waiting time for drying will be longer. I put the above here because you mentioned varnish being totally gone in places.
  3. French Polish materials

    1. Orange shellac is the most common. This produces cloudy orange polish - cloudy because it contains lac wax and will tend to yellow light colored woods such as spruce. De-waxed shellac can be purchased or made by filtering orange polish through filter paper. It is darker in color - almost wine red but is clear. It will polish to a higher shine than orange polish but also yellows light colored woods. De-waxed and de-colored lac are also available from specialist suppliers - some examples are blonde, super blonde and platina, which is the palest. Bleached lac is not recommended. 2. methylated spirits or denatured alcohol. For general work 8 ozs - 250 grams of lac should be dissolved in 32 oz -1 ltr of methylated spirits or denatured alcohol. Obviously work those amounts down for violin work. Strain through fine muslin to ensure mixture is free from grit. Avoid metal containers which can react and color the polish - glass, stainless steel or enameled are best. 3. Oil - I guess take your pick but from experience olive and especially lavender take too long to dry for my taste. Oil wasn't mentioned for use in the source I'm referring to but there is a final rub back with steel wool recipe of sorts mentioned - dissolve beeswax in turpentine {mineral or vegetable} so that a soft paste results. Not sure if this would be needed for violin antiquing work. 4. bed sheets and pillow case qualify as close weave cotton. What I used was cotton balls or fine pore sponge/foam inside pieces of worn t-shirts. Air brush or sable, civett or squirrel hair brushes are other options. Info. for this post is from the J. Williams and company guitar making manual. Even more info. is possible through the Dept. of Labor & Industry Book of French Polishing. Dept. of Building, Sydney Technical College, Polishing Section, Sydney, N.S.W., Australia.
  4. buying a violin upgrade for a teenager

    Firstly, this has nothing to do with me but just reading here leaves me puzzled, scared and somewhat confused on what to do. The good I see is the charm of an old French violin and the student likes to work with it. So my question is can the entire timber of sound coming from the violin change for the worse with the addition of an ebony fingerboard, nut and new bridge? What about other fittings? It is such a gamble that I'd be afraid to play. Maybe find a pro violinist or two in the area that may have an extra instrument they may want to part with. Don't forget the trip to the violin shop so that a pile of instruments can be brought out to see what jr. really likes. good luck
  5. Saving the mold

    I use a two piece mold but only because that's what the website I was teaching myself from said to do. Here's what you'll need. A 1/2" or 12 1/4 mm thick piece of plywood/wood for one section and a 3/4" or 17 1/4 mm piece of plywood/wood for the other section. Total thickness 29 1/2 mm for a mold. Lastly, about a dozen 31mm wood or sheetrock screws to hold the two sections together. The smaller thickness will stack on top of, for the time being, will be the bottom thicker section. When it's time to cut out the form shape you can cut out the outline one section at a time or try both sections at the same time - which may be tougher to do - the object is to have the rib resting surfaces square to the faces of the plywood/wood using a square while shaping. There's no point really in using a two piece mold if squareness isn't going to be the priority. When finally shaped remove the screws one at a time and counter sink the screw heads where they're just beneath the surface of the mold. This comes in handy for leveling the rib/block surfaces using a few pieces of sandpaper on a flat surface - sometimes using a file for leveling blocks and ribs gets old. Speaking of blocks - when you apply glue for attaching to the mold just use a small 3/16" dot and attach to the thicker piece of mold, not the thin section. This is where you'll eventually find out if you squared your cutouts well enough. You'll notice the screws petruding through the other side some. Adjust the heights of all the screws until there's no wobbliness - that'll be good enough. Use a surface that you wouldn't mind getting scratched by the screw tips and watch you fingers/palms while doing so - hurts a little bit. The surface with the countersunk screw heads will be your first plate gluing side. I glue the back plate first so what's next after leveling is to make sure my linings are ready for gluing. Then remove the screws and carefully remove the thinner section of mold without dislodging any blocks from the thicker lower section. As soon as that is done glue in the linings and shape. Spool clamps should be at hand by now so put your plate to the mold and see if you're really ready to glue. If so, size the end and neck blocks, if you choose to do so, and get ready to glue your plate on. I use the back plate first just for the simple fact that I don't want to break any belly wood with possible over tension with the clamps. Be careful with the other edge of ribs, if they're in the way. When it's time to remove the other section from the blocks use a worn, thin 1" putty knife carefully. Glue the other linings now, shape them and get the belly on before the ribs have a chance to do any moving. If movement doesn't bother you then just use the one piece mold like everyone else does. Well, there you have it - one complete and squared box assembly.
  6. Cedar top repair question

    Western red cedar. After all is said and done with making a wrc bellied vso, one will have to accept the fact that what he/she made using cedar can only be called a fiddle, not a violin. Others have mentioned that cellos?, violas and fractional sized instruments can be had with cedar but not the 14" violin size - for some reason it doesn't work soundwise. 30 to 40 grain lines per inch if you want to experiment. Cutting purfling channels are a pain along with belly removal issues are a few things I remember about cedar. Maybe Martin or Ben have an old Craske made with cedar laying around somewheres to provide sound samples - probably a waste of time.
  7. plate tuning specs ?

    Here's something else I found. As usual, written by someone else but I thought worthy of keeping...... ........ if a plate at a given mode 5 frequency is "x" grams heavier than the ideal weight then you can estimate the correction to it's mode 5 by multiplying the excess weight "x" as follows: x 32/24 for a belly and x 19/24 for a back. Ideal weight 65 gr for belly, 109 gr for back plate. ex. {a} a heavy belly at 90 gr and 330 hz mode 5. It's excess weight over the reference weight is 90 - 65 = 25 grams. Multiplying that number by x 32/24 converts it to hz and gives a mode 5 correction of 33 hz: so the idealized mode 5 is 330 hz + 33 hz = 363 hz instead of the present 330 hz.
  8. Seems to me that if you're using 120 then that would equate to 8 notes per second, right? That's pretty quick if that's the case. I wouldn't get distracted by using other exercises/etudes unless you find the one or two etudes that can actually lead you to a better playing #2 Kreutzer - I have no idea what that would be. It is early enough in the year that you could very well be ready for springtime recital. Try this practicing tip from Andrew Victor: 1. practice - until it's right. 2. next practice - until it's right 9 out of 10 times. 3.next practice - until it's right 1st time, every time.
  9. Articulation of Violin Concerto in C major, Hob.VIIa:1

    That's what I'd do - the two previous notes leave no option.
  10. plate tuning specs ?

    here''s something that could help.......... I can't remember who said this a few years back but I believe just for the time being that he is 2/3rds right. .........for more power and less complexity take away some of the curvature and make the center more of a flattish plateau. For a sweeter, more complex tone with less power take the recurve further into the plate [long arch wise] and add a more curved profle from the trough to the peak. Doing so adds complexity to tone at the expense of power. The other 1/3rd of the 2/3rds rightness may have something to do with getting lucky by choosing the right piece of wood, correct arching profile for that piece of wood, the height needed and just plain old luck while going through the rest of the making process.
  11. 44.5 string spacing for the nut and just under 59mm spacing for the string holes in the bridge. From nut/fingerboard line to the 12th fret at the body join can be just shy of 328mm. Doubling the 328 mm to the bridge saddle plus a mm or two for compensation in addition to the already 356mm gives a scale length of 358. IAs of recent with myself I have contracted a severe case of Faulk-itus. That would otherwise be known as classical guitar making. Since Aug. 2017 - almost three down, one more to go. .
  12. plate tuning specs ?

    Let's see - 370 multiplied by 370 multiplied by a plate weight of 71gr. = still to heavy, imo. The mode 1 is sorta getting close so if you decide to keep thinning - be careful.
  13. Drying A Pigmented Oil Varnish

    I can't tell what you're really working with material wise but just for a scroll/pegbox try mulling the pigment into the varnish you said dries fine. If you want a brushable varnish all I can suggest is to keep at it without ending up making a bunch of unnecessary material. That usually means adding thinners like spirits of turpentine or mineral spirits with your cold pressed oil being used as a retarder. Retarder means to slow down drying. What's bad about turps, min. spirits and more than likely plain linseed oil is that they kill the gloss sheen. Maybe that's expected for some but I hate it. Afterwards just apply clear over your colored work. As for a ratio. If you are powdering your colophony into hot oil then maybe a 1 to 2 ratio gum to oil measured by weight. How that dries by itself after application to wood I have no idea, just a suggestion.
  14. Drying A Pigmented Oil Varnish

    Use the same method on a scrap piece of wood. After you think it's dry enough try peeling the finish off of the wood. If it seems rubbery then it's too much linseed oil.
  15. Glair and Oil Varnish

    1. To me that is a good thing. Using egg white for a seal coat the first dried coat is sort of opaque looking/no sheen , the second coat is where shinyness shows. The sheen, weather dull or shiny, still doesn't matter to me. If it works on the canvass of the old artists' for holding their media it's good enough for me on violin wood. 2. How do you know that or who told you that? Sir, with all do respect, I ask. 3. I understand how you go about varnishing with the non-antiqued method. What or how you ground your work doesn't matter to me. If you were taught a certain way or learned something else you should keep doing what you do. After all is said and done here I'll be the only one sealing with eggs - fine with me. 4. Again, how do you know that? I've found egg white is difficult, well not difficult, but not easy, to remove from wood using turps spirits. That tells me it stays on the wood. As for oil staying on egg sealer? First, I'm not 100% sure two coats of egg seal the wood in the first place. If it doesn't then I have a little oil passing thru to what could be wood. I'd think that would be o.k. If the oil lays on the sealer without penetrating then good, that's what I need. No chippies yet - I just don't see how that could happen just by lying around on egg white sealer. Bumping into music stands or a bow riding along the surface of the belly in a case is just a by-product of the nature of playing a violin - it happens no matter the finish on the wood. My antiquing work is getting better - you guys better watch out.