Bill Ballard wrote: ><snip> The 6th and 7th octaves just sparkle. The bass can easily go up a >notch in forcefulness, if needed. For tonight's concert, I sat at the back >of the 400-seat closed concert shed, and even with the piano pushed back >in from the proscenium, and at half stick for this Dvorak piano quintet, >even at this suppressed volume, the sounds were very clear. Sustained and >projected. Hey! You have a good time! <glad> >>Can you describe the solution you used? What dilution, which >>alcohol? Or premixed? Did you find that the color was a problem? What >>impressions did you have as you >applied it? Did you do any wet-voicing >>with it? > >3# clear shellac from the local hardware store (date of manuf: 10/4/01) >which I cut back to 1#, for caution's sake using the instructions on the >can. Denatured alcohol the next shelf down from the shellac. Methyl, >Ethyl, I can tell'em apart, they've got the same freckles and buckteeth. >Color was not a problem. (BTW, that's one of the reasons I went down to >1#: nice white Steinway hammerfelt should have big butterscotch stains on it.) Yes, I doubt that the lovely garnet shellac would be quite the thing ... I've used ultrablonde, but I thought I might try some of the bleached flakes as well. >As for the shellac's ability to penetrate the felt mass, as mixed, it had >(SWAG) 25% of the viscosity of plastic/acetone, but it flowed right into >the shoulders even with a pre-existing plastic content. Interesting question, how it gets past the plastic, since I don't think that pyralin will dissolve in alcohol (will it?) There seems to be more to penetration than just the viscosity number. >Wet-voicing? Do I eat my brownies after only 11 minutes of baking time? >Does the bear sit down in the woods? No, I regulated or tuned. (I >especially wouldn't want to hit a wound string with a hammer still wet >with shellac.) point well-taken ... drying time: >I did put a drop of plastic/acetone and the 1# shellac on a piece of >mirror. The plastic was solid nearly instantaneously, the shellac was >still gummy after a minute. But if we're going to experiment, let's be >rigorous about it. First, observe and time the evaporation of the >solvents, equal volumes of each. Then, before observing the hardening of >the resins, make sure that you samples have the same % of solids. One >might assume that viscosity and solid content might be directly related. >Maybe not though, in which case rigorousness of the experiment just got >more complicated. IMHO, you can't be rigorous about shellac vs. acetone drying time unless you figure out the age of the shellac and the water content of both the shellac and the alcohol. Methyl and ethyl may have some different properties as well (aside from toxicity) but I don't know what they are. Unless you work out how much water is in there, I don't see how you could test for methyl versus ethyl as a carrier. If you want to follow up on your experiences, Bill, I think you might try going to that shellac website: http://www.woodfinishingsupplies.com/Shellac.asp and getting some of their super-dry alcohol. It has even less water than the liquor store 190 proof. It seems to me that shellac freshly made from flakes with the really water-free alcohol may well behave in a hammer in a quite different way than pre-mixed shellac from a hardware store, cut with the denatured (which is now only 4% methanol, I believe, but has quite a lot of water in it.) Whether it works better or worse or just different we won't know until a few people have tried it. It may be that the water in the mix affects the wool in a gentling sort of manner. It may be that the slower drying time might change the voicing characteristics as well. Mr. Dunlap kindly wrote us about how drying alcohol attracts moisture from the air which affects felt. I'm quoting his post below, since I found it very interesting. Has anyone worked out whether acetone does the same thing? Lots to find out. Thanks for sharing your initial observations. Do let us know how that piano behaves down the road. I have no idea what was happening with those "hissers" you found in the third visit, but I'm not sure that cure time can be ruled out. If you let shellac get old enough and wet enough, it never does harden up. Susan Date: Thu, 06 Sep 2001 19:56:15 -0400 To: pianotech@ptg.org From: "Earl S. Dunlap, Jr." <dunlapes@home.com> Subject: Hammer Juice Solvents, Alcohols, Long Sender: owner-pianotech@ptg.org Reply-To: pianotech@ptg.org List: In case it helps when you make your choices ethanol is "grain alcohol" and will not contain less than 5% water when water is boiled out of it to concentrate it from mash since water and ethanol form a "constant boiling mixture" at 5/95 percents, respectively, of each. This means one cannot make ethanol stronger than 95% when boiled just with water . Ethanol can be made to go to 100%, I believe by boiling with benzene (highly toxic). It would then be called "absolute" ethanol although there would be residual benzene. The U.S. Government permits use of several formulas (schedules) using fixed percentages added to ethanol of various chemicals so it is "denatured" or made undrinkable (poisonous) and thus not taxed as drinkable alcohol. These formulae are different enough that some may work better for some industrial purposes than others: yours? Some could conceivably be made back into drinkable form more easily than others (none easily.) E.g., one of these uses methanol or as the only denaturant. For this reason the BATF (Bureau of Alcohol Tax and Firearms) requires--or at least used to require--special handling/permitting for this grade. This may be available to you; you could call the BATF for information. "Wood alcohol," methanol, is easily obtainable as 100%, and both this and denatured ethanol are sure to be cheaper than 190 proof drinking alcohol. Methanol may work well to dissolve shellac, but methanol vapor at any significant concentration air would be something I certainly wouldn't recommend. The denaturant formulas in ethanol (and possibly colorant) may possibly be a problem for piano technicians. The denaturants are indeed toxic, but are in low concentrations. Depending upon ventilation and quantity used they may not give you difficulty. Again, 5% water is present in all grades unless sold as "absolute" ethanol. If you feel you need more info. all the people that sell alcohol--for that matter, all chemicals: and what isn't a chemical?-- must be prepared to supply those that request it an MSDS, a Material Safety Data Sheet, that tells more than you'll want to know about that chemical. You may call the chemical manufacturer's number (or the state or federal EPA if you get a hard time)! When you read the MSDS, you'll be scared to death. Their respective MSDS' make aspirin and table salt to appear as terrible poisons: and don't bother reading the one on saccharin! I'd guess this "crying wolf" is to minimize potential legal problems for the manufacturer. By the way, any of these alcohols are very water soluble (as is acetone (very much more volatile & thus more flammable) or methyl ethyl ketone (a bit less so)), and when they evaporate rapidly, will chill the area drawing moisture from the air--more so in humid climates. This moisture has the potential to release the press in the wool! (Re: Susan Kline's correct "steam in a bottle" comment on 04 Sep 2001 18:30:15) I could say lots more but I'm sure you're sick of it by now. Apologies. Thanks for your patience. Keep on doing the great jobs you're doing, RPTs. Earl Dunlap, Textile Chemist and lurker (with your kind permission)
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