#2 should read "swabbed" not swapped. Time for dreamland. Forgive any other typos I missed in my haste. David Love www.davidlovepianos.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of David Love Sent: Wednesday, January 20, 2010 10:59 PM To: pianotech at ptg.org Subject: Re: [pianotech] Renotching-Repinning-Reusing Bridges in rebuild Joe: First see my follow up on the procedure, it's a bit different than what I wrote with my first post. Numbers refer to your questions below which I've also numbered 1: String # 52 on a Steinway B is .038" in diameter. Even going with a #7 pin with .064" between the pins still leaves you plenty of room. 2: I use the epoxy mostly to strengthen the hole so I can redrill without chipping and to seal the bridge top and make it a bit harder. The epoxy is painted over the entire bridge top and swabbed lightly into the holes. I don't fill them but you can and let the epoxy seep into the cracks and crevasses in the bridge to solidify it. When I drill out the holes, however, I don't really want to be drilling into something terribly solid rather just a quick reaming, like a second pass on a pinblock taking out very little material. 3: Surprisingly I don't seem to run into intersecting bridge pins that often. When laying out a new bridge I adjust the rear bridge line so that I don't get intersections where necessary. It's usually only in a few spots. If I do have the problem on an existing bridge it's usually not with the pins hitting each other dead on but trying to squeeze by each other. I usually just file one side of the lower part of the pins where they will contact each other slightly flat so that they can more easily slide by each other. I only do this where I estimate they will come in contact. Generally it's fairly deep under the surface of the bridge. 4: I shoot the bridge with lacquer because it looks nice but the UV protections is a side benefit. After sanding the epoxy with a stain underneath, the epoxy looks cloudy. I don't use DAG so I shoot it with lacquer to put a nice finish on it. As I mentioned in a follow up post (don't know if you saw that) I clean, sand and notch the top; then coat it with epoxy; sand the top again lightly; pin the bridge; put a drop or two of thin CA glue at the base of each pin; then shoot the entire bridge with lacquer masking off the board. So the pins get a light coat too. I use an aerosol dispenser because I feel I can control the spray better and keep it to a couple of light coats. After that I run a wide piece of tape over the top of the bridge on top of the pins just to cover the bridge top and then varnish the board (I prefer varnish over lacquer on the board but either way is fine). I put the tape there just to be sure I don't drip any varnish on the bridge top. BTW the longer you can wait for the epoxy and lacquer to cure before stringing the better as it gets harder over time. I should add that my general procedure is to recap the capo section (especially on a Steinway). Often I find the need to increase the speaking lengths in that section as well as increase the bridge height. So most of the time I'm just doing the above on the tenor and bass sections but there are exceptions when I do the whole thing. With a new cap in the treble it gives the bridge a kind of two-toned look as the tenor and bass will be somewhat darker especially if I stain them and the treble section will have a new quarter sawn light maple look. David Love www.davidlovepianos.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Joe DeFazio Sent: Wednesday, January 20, 2010 10:01 PM To: pianotech at ptg.org Subject: Re: [pianotech] Renotching-Repinning-Reusing Bridges in rebuild Thanks, David. I appreciate your replies. I have a few questions, which I have interspersed among your comments (which I reordered for the continuity of my questions). 1: Although I have "gone up" in bridge pin size when repinning on some occasions, I have usually done so in the tenor and/or bass. I am interested to learn that you do it in the high treble as well. I haven't, out of concern about the rather slender bits of wood between the bridge pin holes up there. As an example, the S&S B in the shop at the moment has #6 bridge pins in the treble (.076), and the "lands" between them average only about .074 (you can barely fit a #6 bridge pin between less than half of the pin pairs). Going up to #7 (.086) would leave only about .064 of wood between the holes. I grouped your comments above together, because they point to the use of epoxy as a strengthening agent, allowing larger holes to be used with smaller "lands" of wood between them. I hadn't thought of that. 2: Now, when you redrill the holes, you presumably remove some or most of the epoxy (for instance, Pianotek recommends an .081 bit for #7 pins, and the holes must have originally been slightly enlarged .076+). So, is it your understanding that the epoxy wicks into the wood in sufficient quantity to remain in and strengthen the "lands" that are left after redrilling? 5. Repin the bridge. Set the pin heights by tapping them down to uniform height, don't file them.... 3: When you do this, how do you handle intersecting bridge pin holes (as can happen along the most curved part of the bridge)? It makes sense to keep the longer pins in the front (since it is the most important termination area). If you shorten the back ones, how do you do it? Cutting them deforms the cut end, which would be terrible for the integrity of the hole. I suppose you could grind them.... 6. Shoot the bridge top with clear lacquer. A couple of light coats. You don't want a huge build up of lacquer. From: "David Love" <davidlovepianos at comcast.net> Date: January 20, 2010 5:03:16 PM EST Correct that. Actually I recut the notches before I apply the epoxy coating. That way the notches get sealed as well. Then I redrill and then lightly sand the bridge top to smooth out any roughness in the epoxy. Then repin, CA, coat with lacquer.... 4: Is the purpose of the lacquer for UV protection (as William Monroe suggested in his post), or for another purpose? If I understand you correctly, the bridge top and notches have already been coated with epoxy. Am I correct that the bridge pins get lightly coated with lacquer, as well? Thanks again, Joe DeFazio Pittsburgh -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100120/520cce4e/attachment-0001.htm>
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