<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "> A couple of things about brass that haven't been mentioned in this thread:<div><br class="webkit-block-placeholder"></div><div>1. I'm told that machinists generally have a second set of drill bits for brass whose cutting edges have been ground to have the cutting angle greater than 90û. That is, the angled cutting edge on the tip has been "dulled" by running a stone across the inside of the flute so the part that actually contacts new metal has a sharp edge but at greater than 90û. Think of taking a small slip stone and holding it nearly parallel to the drill bit and "touching" the cutting edge.</div><div><br class="webkit-block-placeholder"></div><div>The same can be done with these reamers. It greatly reduces the tendency of the bit to grab the brass. !</div><div><br class="webkit-block-placeholder"></div><div>2. Brass gets harder and more brittle with age. (As in more prone to breakage, and more likely to make noise!) Crystal structure changes. To thoroughly renew the brass, heat it red-hot (don't quote me exactly on this, I've not actually done it), and quench it in water. The opposite of steel. It redoes the structure from getting coarser over time to being very fine again. Dunno how close to new you can get. Perhaps there's a machinist among us that can comment?</div><div><br class="webkit-block-placeholder"></div><div>My experience is that even 20 years is enough to have new brass sound different.</div><div><br class="webkit-block-placeholder"></div><div>Not to mention 3. There are different kinds of brass, as in the red flat-topped Steinway agraffes we all love so well. They're harder--try the scratch test.</div><div><br class="webkit-block-placeholder"></div><div>Doug Wood</div><div><br class="webkit-block-placeholder"></div><div><br class="webkit-block-placeholder"></div><div><div><div>On Jan 7, 2008, at 7:05 PM, Donald McKechnie wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Alan, Mark and Fred,</div><div><br class="webkit-block-placeholder"></div><div>Thanks for the tips on the proper use of the reamers. Fred, I can see the radius difference by using a magnifying glass on the reamer I have and zooming in the picture on the MSC site. The reamer I have looks like a countersink with a pilot point. The one on the MSC site has a gentle radius transition starting from the point.Ê</div><div><br class="webkit-block-placeholder"></div><div>I will go with the polishing suggestion Alan mentioned if I can find a proper polishing tip locally. Otherwise, it will be the slower method as I want to try fixing the buzz as soon as possible. This problem is getting on my customer's nerves a good bit so I would like to be the hero sooner rather than later. :-)</div><div><br class="webkit-block-placeholder"></div><div>Thanks,</div><div>Don<br><div> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><br class="Apple-interchange-newline"><div><br class="khtml-block-placeholder"></div><div>Don McKechnie</div><div>Piano Technician</div><div>Ithaca College</div><div><a href="mailto:dmckech@ithaca.edu">dmckech@ithaca.edu</a></div><div>607.274.3908</div><div><br class="khtml-block-placeholder"></div><div><br class="khtml-block-placeholder"></div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span> </div><br></div></blockquote></div><br></div></body></html>