Just trying to review my chemistry I referred to wiki answers. Here is what I found. Now to your question. H2O2 is a very weak acid in water, much weaker than vinegar, but still 103 - 104 times stronger than water itself. For all practical purposes, then, we don't consider H2O2 to be an acid. However, in strongly alkaline solutions, H2O2 is deprotonated preferentially to water to give the HO2- (hydroperoxide) ion, analogous to the HO- (or OH-) ion produced when water is deprotonated. This ion is the reagent in the Dakin reaction giving catechols and quinols. So, it has some acid properties. H2O2 is a much weaker base than water, and the H3O2+ ion is very unstable, obtained only with the strongest of acids (superacids). However, H2O2 can be dissolved in polar solvents which are far less acidic than water, some of which may even be bases - such as ammonia. In such circumstances, H2O2 can be the principal acidic species present in solution. Acid-sensitive compounds, such as Grignard reagents, are destroyed on protonation by hydrogen peroxide just as they are by water. Wow... lots of words. Let me sum that up for you. Hydrogen peroxide is not an acid. Cream of Tarter: this is what Wisegeek has to say. Cream of tartar is the common name for potassium hydrogen tartrate and is essentially an acidic salt. It is manufactured by mixing potassium hydroxide with tartaric acid. For centuries it has been formed from the sediment left over in barrels after the winemaking process. Cream of tartar also has other household applications (other than for use in cooking). It can be used to clean brass and copper cookware. It is also helpful in removing stains from sinks and bathtubs. Cream of tartar and hydrogen peroxide can remove even the most stubborn rust stains, without scratching a delicate surface. Always test the solution in an inconspicuous area first, however, to ensure its suitability for use on that surface. Apparently, one can use either to clean and in our experience as piano technicians clean and whitening ivory. Hydrogen peroxide mixed with ammonia is used to "bleach" hair in the professional setting and at home is used by itself in a 3% strength, allowing more time to work. Mixed together Cream of Tarter and Hydrogen Peroxide may provide an easier to work with and more efficacious solution to the ivory cleaning and whitening process. I have old ivory blanks to experiment with during the summer break. If you decide to use stronger 30% Hydrogen Peroxide it may work quicker, but be sure to use rubber gloves to protect your skin! Henry Nicolaides Piano Technician Southern Illinois University > From: johnparham at piano88.com > To: caut at ptg.org > Date: Fri, 23 Apr 2010 20:13:15 -0700 > Subject: [CAUT] Whitening Ivories > > List, > > I am not a CAUT tech, but I monitor this list because of the variety of > perspectives and opinions that it offers. > > The recent discussion of whitening ivories caught my attention. Tonight > I experimented with the idea of using hydrogen peroxide and cream of > tartar that I read about here. This is what I found: > > 1. First I used a topical solution of hydrogen peroxide (3%)available > from a drugstore on an old dirty and dingy-looking ivory head. Hydrogen > peroxide by itself seemed to clean the ivory very easily, similar to > using acetone to degrease metal, but it left a faint film on the ivory. > When I scratched it with my fingernail to simulate playing, I polished > the ivory. To finish the cleaning process, therefore, I had to buff the > key with a cloth. > > 2. Next I used 10 grams of 3% hydrogen peroxide with three teaspoons of > cream of tartar mixed in. Using a paper towel, I dabbed a little of > this mixture onto the ivory and began to polish it. The cream of tartar > immediately precipitated out as I polished the ivory. The end result > was a very clean, shiny ivory. I did not need to buff the ivory because > there was no film on it. I like the results so much that I will use this > technique on the old Chickering action I am working on this weekend. > > I am curious about specific techniques that you all have discovered that > work well. > > What specific ratios of solutions have you experimented with? Should I > use less cream of tartar so it does not precipitate out so quickly? > > Does a higher concentration of hydrogen peroxide work better to not just > clean but to whiten the ivories as well? > > Does the cream of tartar act only as an abrasive polishing agent? > > After using the acidic solution of hydrogen peroxide, is it necessary to > neutralize the ivory with a base to prevent any further interaction with > residual hydrogen peroxide and the ivory? > > Thank you for sharing your ideas. > > -John Parham, RPT > Hickory, NC > _________________________________________________________________ The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_4 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20100424/390470c3/attachment.htm>
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