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. A bit to early when I wrote that to think in an orderly fashion. David Love www.davidlovepianos.com -----Original Message----- From: David Love [mailto:davidlovepianos at comcast.net] Sent: Wednesday, January 20, 2010 6:46 AM To: 'pianotech at ptg.org' Subject: RE: [pianotech] Renotching-Repinning-Reusing Bridges in rebuild 1. Pull all bridge pins, clean bridge top first with denatured alcohol and rags to remove old graphite then sand bridge flat just removing string grooves. If you are not going to use graphite on the bridge later then stain the bridge top with whatever color stain you like to make a uniform color (I like a dark red mahogany--darker is better because of the old graphite stains). If you are going to regraphite the bridge then skip the staining. 2. Paint bridge top with thin epoxy and lightly swab old bridge pin holes with toothpick to resize and support holes for redrilling. 3. When epoxy is cured lightly sand bridge top with 400 grit just to get it smooth. 4. Redrill holes for new bridge pin sizes and then recut notches. Drill for #7 in treble, #7 or #8 in tenor, #8 in high bass, #9 in low bass. 5. Repin the bridge. Set the pin heights by tapping them down to uniform height, don't file them. Put a drop or two of thin CA glue at the base of each pin to secure them. Enough to wick in put not pool. 6. Shoot the bridge top with clear lacquer. A couple of light coats. You don't want a huge build up of lacquer. That's basically my procedure. It's important not to try and drill the holes until after the epoxy treatment to avoid chipping. I replace all #6 pins with #7 pins. David Love www.davidlovepianos.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Joe DeFazio Sent: Tuesday, January 19, 2010 9:05 PM To: pianotech at ptg.org Subject: [pianotech] Renotching-Repinning-Reusing Bridges in rebuild Hi all, I would like to get some feedback from the rebuilders on the list about the procedures that you follow in reusing a bridge without recapping. I am always tinkering with my methods (in an attempt to improve them, hopefully!). If the bridge is structurally sound (no splits or cracks, no cap delamination), and if speaking lengths are not changing due to a rescale, I reuse the bridge. I also sometimes reuse bridges with small splits at some bridge pins; I trust WEST System epoxies. If splits are bad, or the cap attachment is suspect, I recap. I will outline the bridge reuse protocol that I am currently following, and would like to hear your opinions about the procedure, specifically about any steps that you add/omit/reorder/do differently. 1) Measure old bridge pin diameters, remove and save them. 2) (optional) If bridge pins are shallow, deepen holes with a bit slightly smaller in diameter than the bridge pins. 3) Resurface bridge to so that string cuts are barely visible. Resurface bridge sides. 4) Vacuum out bridge pin holes. 5) Temporarily partially reinsert old bridge pins (1-2 mm depth). Rationale: keep lubricant from next step from entering bridge pin holes. 6) Apply lubricant (gray McLube, DAG, or raw graphite) to top of bridges. If graphite, seal with Permalon. 7) re-remove old bridge pins. 8) Renotch bridges, bisecting holes and slightly deepening notches 9) Epoxy in new bridge pins (WEST system). Use overflow to seal notches. 10) Level new bridge pins. I have tried various methods for this: coarse/fine file, ROS, and after a discussion here a year or two ago, just leaving them unleveled. This had the benefit of not applying undue heat and vibration to the pins/epoxy, but I was unhappy with it aesthetically, as overlapping holes in the treble prevented the pins from ending up at the same height. Open to other suggestions (air inline sander, anyone?).... --- I am especially interested in feedback on how you accomplish (or don't accomplish) steps 2, 5, 6, and 10, the order in which you do things, and why you do things as you do. Thanks, Joe DeFazio Pittsburgh
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