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About JoeDeF

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  1. Making a harp

    Birch is used not because it is birch, but because "Baltic" birch is a plywood, is thin, and the better stuff is guaranteed to have no voids in any layer. The harp soundboard works differently than the other stringed instruments that you mentioned, in that the soundboard has many string holes through it and the entire tension of the strings pulls on the soundboard. For lower cost harps, Baltic birch is much more foolproof to work with, offering greater resistance to splitting and deforming, and is more dimensionally stable under changing humidity levels. Finer harps tend to use quartersawn spruce, just like violin and piano family instruments. But that comes with certain risks and complications (and graduation). For one take on the choices, see: Geoff1954, I think that you should plan on installing sharping levers as part of the build. Yes, they are relatively expensive (compared to the other materials you mentioned), but they allow so much more versatility. If you don't have the budget for them right now, at least buy one of your preferred brand, note its dimensions, and make sure that you allow room to add and adjust them. The plastic (or composite, not sure) Jordan levers are about the cheapest decent levers, AFAIK (I haven't used them), and they look to be very easy to install and adjust. I would stay away from the cheap Roosbeck lever with two poles; though at first it seems like a good idea in that it vaguely mimics the much more complicated mechanism in pedal harps, the pull of the transverse wave traveling along the strings tends to cause the poles to work against each other and also work against the friction which is the only thing holding the lever in the engaged position - all of this can lead to a wobbly, wavery sustain. It is tempting to make a bigger harp with more strings "on the cheap" by using all nylon strings, but nylon bass register strings really don't sound good. Just FYI. Best of luck with it.

    Wait, you're varnishing kitty litter? What kind of varnish? At least we're back on topic....
  3. There is another option to geometry

    Catenary chains (curves) are used (with some adjustments) in laying out piano bridges. They accurately describe an idealized progression of speaking lengths (the vibrating portions of consecutive notes). We typically have to deviate from the idealized curve for some reasons I won't get into here.
  4. Beady eyes... extreme version of fisheye

    I never used a fisheye eliminator with oil varnish, but I do use it in refinishing with nitrocellulose lacquer (on pianos) when needed. The photo shows basically the opposite of a fisheye, though, so I doubt that fisheye eliminator will work. Basically, a fisheye is an area of finish that has been unevenly contaminated with silicone (typically in a furniture polish), causing a lower viscosity spot which ends up sinking below the rest of the lacquered surface when dry. A fisheye is a dip, not a bead. My understanding is that fisheye elimator works by adding a small amount of silicone (and possibly other chemicals) to even out the viscosity of the finish, thereby allowing it to dry to a uniform depth of coat once the solvents evaporate. Once you add fisheye eliminator to a finish, the general idea is that you must use it in every additional coat (whether now or in 50 years), or the fisheye problem will most likely come back and be worse than it originally was.
  5. Beady eyes... extreme version of fisheye

    I know that you are very knowledgeable in general, but please take care of yourself. Personally, I wouldn't touch xylene with my bare finger. The quantities may be small, but I err on the side of caution; we only get one body and brain, and they have to last....
  6. Custom suction rib system, save 80 % of timeā€¦

    The "Safe-T-Planer" might be the most unsafe tool I own! (And I own a lot of tools.) I rarely use it for that reason. Once, due to the side-bearing forces as the stock engages the edge of the planer, the friction fit between the chuck and tapered spindle gave way, and the "Safe-T-Planer and chuck went spinning across my shop like a deranged, heavy, razor-sharp top. I jumped out of the way pretty quickly. I found it to be unsafe in a few other operations before putting it on the shelf (possibly for good) and turning to other methods for thicknessing. It looks like you made a nice holding fixture, though; good job with that.
  7. Help with mandolin - advice please?

    Thank you, Marijan. The instrument has a nice lively sound. I enjoyed listening to it. You should be proud of your work.
  8. Help with mandolin - advice please?

    Hi Marijan, Thank you for sharing your work on this mandolin. Is there any chance that you could share a link to the soundfiles of this instrument? I would love to hear it, and I bet some others forum members would also.
  9. My first real label. Is it missing something?

    Fixed it for ya, Nick: As they say around here, "Go Stillerz!" (For readers not from the US, the added symbols have deep runic meaning and inescapable metaphysical implications.)
  10. Need Help with Cello Butchery

    Here are a few somewhat speculative ideas for getting the part of the top that has been pushed in back up and level, and then reinforced: 1) Use a turnbuckle lowered through the F hole to push the indented part up. You can buy a small turnbuckle at most home improvement stores for a few dollars, and also buy a piece of threaded rod to replace the "normally threaded" part of the turnbuckle. Cut the ends off of the threaded parts and make (wooden or polyethylene or whatever) caps for them to push out on the cello. Cut the the threaded rod so that the whole assembly is about the length of the soundpost when the turnbuckle is at a neutral point in its travel (i.e. - so that you can easily make it longer and shorter than the soundpost). This Stew-Mac guitar tool should give you the idea (though a regular turnbuckle will be easier to turn through the F hole with your soundpost adjuster): You could use the same tool to clamp your thin Baltic birch patch in place. I would probably suspend and secure the cello F holes down, slide the patch into place, try to maneuver the turnbuckle so that it is standing on the patch, and tighten it down. Then, I would use several applications of water-thin CA glue to glue the patch in place. You can get it in there with a pipette or a syringe with a carefully bent needle. Capillary action will suck in in pretty effectively. (Standard disclaimer: of course I wouldn't use CA on cracks except in this type of low quality and currently worthless instrument.) Whether this approach is feasible or not will depend partly on your supply of patience and skill with extensible magnets, grabber tools, etc. or 2) Pull it up. IIRC, Cremona finishes are pretty smooth (lacquer?). Go to Harbor Freight and get their smallest suction cup dent puller. Clean the top for a good suction fit, and see if you can get it pulled up that way (use your other hand to push down immediately adjacent to the crack while pulling up). If that doesn't work, you could use double sided carpet tape or a reversible glue to attach a little wooden handle to the top, then pull it up. Then, rotate/wiggle the carpet tape free or carve away most of the handle and use your glue's solvent to remove the last bit. Once it is pulled up (and maybe thin CA glued), you could suspend the instrument face-down and apply as a soundpost area reinforcement either a few coats of thin CA glue and then one coat of medium viscosity CA glue, or (my preference) a long-set thin epoxy which will penetrate deeply into the cracks and fairly well into the wood also. System Three Clear Coat is what I sometimes use on piano soundboards (that's my trade; penetrating epoxy is an accepted part of piano rebuilding for certain jobs and has been written up in the Piano Technicians' Journal). or 3) Use a "WWI Tank clamp" (that's what they look like to me). With this type of clamp, a tiny hole is drilled right along the crack, and then a piece of wire with a clamping pad is passed through from the inside. The body of the clamp stays outside. The wire is threaded into the clamp's tightening mechanism (I use a piano tuning pin), which draws the assembly together, leveling the crack. Once the crack is glued, the clamp is loosened and the wire is cut. I suppose you could even use the patch as top layer of the clamping pad, get it almost tight, then inject thin CA and finish tightening it down. Once the CA is cured, loosen the clamp, cut the wire, remove the wire and whatever you used to anchor the wire. Here's a picture of one I use on piano soundboards (you might make a smaller one). You can then fill the tiny hole along the crack. Since the instrument is worthless as is, this is a chance to experiment a little bit, and maybe learn a few skills or techniques that you might use later in other situations.
  11. Perry Sultana...

    I had forgotten about this. Thanks for reminding me; it is a good resource. The part I enjoy the most is the "Moisture Resistant Joints" section, which reads:
  12. Wondering the origins of the violin

    I was expecting a rebab, rebec, vielle, gamba type of thread. Sorry I don't know enough to help you with info about your violin. But I like the green!
  13. Pegheads

    Assume nothing about the glue being used; you don't know what it is. I remember the directions recommending polyurethane glue, and hearing of CA glue (super glue; cyanoacrylate) as a recommendation. Muswell (above) also mentioned Titebond (PVA). None of these glues are water soluble. CA glue is softened by Acetone. Some PVA glues respond to some milder solvents like "De-Glue-Goo,"and heat and moisture (steam) will soften many of them, but they're not all the same. Polyurethane glue is very hard to remove; I don't know a good solvent for it. The one thing I'm fairly sure of is that if you damage the pegbox or neck, or heaven forbid, the corpus (or body) while trying to remove the Pegheads, the repair will cost far more than a new set of Pegheads (or Knilling Perfection Planetary Tuners, which are cheaper and plainer but essentially the same mechanism). Unless you have excellent woodworking skills, tools, and experience, I would either take it to a luthier or just get a new set for your new cello. If you have a reamer and can follow directions and money is really tight, you may be able to install the new set yourself; that's far safer than uninstalling a set.
  14. Bass bar tuning

    This principle is still in use in the Erhu (China), Kamanche (Iran and nearby nations), and other instruments (including most spike fiddles that I know of). They tend to have a tiny surface area as compared to Western bowed instruments, but can project very well.
  15. Fake maple flaming?

    HI Mason, It pretty much has to be painted on; look at how it stops at the edge (very visible in at least three of the pictures). Real flame is a perturbation in the growth pattern/fiber direction in the wood, and would be visible from the edge (though it would look different since the edge is more or less perpendicular to the back and would show different aspects of the fiber pattern). (Edit) In the electric guitar world, there are nearly paper-thin veneers that are sometimes pressed onto the curved body of the instrument for looks (and in the cheapest ones, a printed piece of paper is used as a substitute for the veneer). Though it might be possible to do something like that in a violin, that technique doesn't seem to have been used here. I just wanted to point out in this edit that someone who really wanted to make a very thin layer of real flame stop at the edge could do so (though why or if they might want to, I don't know).