I wouldn't scrape the dag off, clean it off with denatured alcohol and a rag. Scraping makes it too easy to create an unlevel bridge top with the variation in widths of the top of the cap. Afterward I would sand down to the bottom of the string groove or at least to the point where there is no indention--sometimes there is a mark left by the string. That's ok. Since that is already the level at which the string is resting, it won't change the existing bearing. If there is inadequate bearing because of the depth of the string grooves then you either need to recap that portion of the bridge or lower the plate. My preference is to recap the capo section as a general procedure in most cases. Once you have sanded the bridge top flat you will need to recut the notches with a chisel as the bridge cap termination will have migrated out beyond the pin line. Paying attention to these details is everything in creating clean terminations and a more focused tone. Of course, don't forget the capo bar reshaping and the proper dressing/replacement of the agraffes. The devil is in the details! David Love davidlovepianos at comcast.net www.davidlovepianos.com -----Original Message----- From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of McNeilTom at aol.com Sent: Wednesday, January 23, 2008 3:55 PM To: caut at ptg.org Subject: Re: [CAUT] bridge cap sanding Here at UT Austin, when restringing a piano, we replace agraffes and replace bridge pins. Standard bridge procedure includes, scraping off the old DAG, sanding the caps, gluesizing the pin holes, re-notching the bridge, etc. Here's my question/comment. When sanding, the old string groove is not completely removed, but it is minimized significantly. When I'm not trying to alter downbearing, just reproducing what was there (mostly), is that OK? In other words, is leaving a little groove a problem? Is removing it completely more of a problem or more desirable? Y'all have fun with this one. Thanks, -- Jeff Farris shape in the new year.
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