I should add that if the bridge is getting nickel/stainless/whatever pins that are rounded on top, I'll do any depth drilling that is needed as soon as the old one are out. Then, when installing, I have two different punches I use that Dana Mazzaglia (http://www.mazzagliatools.com/) made. I ground the tip down on one a little and now I have two depth settings I use for installing the pins. For copper pins, I just drive them in and then use the sander, for nickel/whatever, I drive them with the punch, just short of marking the top with the punch, then they are all even right away. William R. Monroe On Wed, Jan 20, 2010 at 4:14 PM, William Monroe <bill at a440piano.net> wrote: > Hi Joe, > > My procedure doesn't differ all that much from yours, but here goes: > > 1. Pull old pins and record size - discard into recycle bucket. > > 2. Resurface bridge, either using a handplane, or sandpaper, depending > upon the amount of material to be removed, whether or not the bridge cap has > any steps in it, and my mood. I don't specifically remove the old DAG first > on an old bridge - it'll just get DAG again in my shop so....... > > 3. Sand the sides of the bridge. > > 4. Vacuum up the mess, then blow the old bridge pin holes with compressed > air. > > 5. Apply DAG - judiciously. I try not to slop over the edges, into the > notches and such, but I'm not obsessive. > > 6. Re-Notch bridge to the pin hole centerline or just behind it (into the > bridge, that is) - Makes the bridge pin the termination point for the > speaking length again, and cleans up the notches. > > 7. Epoxy in new bridge pins with West System, then, while still wet, use > panty hose (I prefer knee-highs [?]) in a shoe shine method to remove > excess epoxy and seal the notches, and the bridge root. I've tried two > different ways to apply the West System: the first method is to mix it up, > put it in a hypo-oiler and (using a spring clamp to speed up the flow) fill > the old bridge pin holes with the stuff. I find I need to mix in two > batches this way, sometimes three. The other method is to mix a small pot > of West System, and dip the pin prior to driving it. I think I prefer the > latter method. It's a bit quicker, and I only have to mix one batch, but > the first method will do a better job of filling any voids or cracks in the > bridge root. > > 8. Level Bridge pins with a belt sander and high-quality belts - it makes > a huge difference. I used to use coarse grit belt, followed by a quick > filing to clean up, but now I level them with the coarse and clean them up > with a p220 belt. Coarse grit does a good job of not heating the pins up, > so long as you don't sit in one spot from start to finish. > > 9. With the board taped off, shoot the whole mess with lacquer. Unless > you use a coatings epoxy, it is not UV resistant, so lacquer on top. > > Of course, as with any of my "systems," I'm not married to the procedure > and there is room for exceptions/changes, depending upon the condition of > the bridge cap, depth of grooves, downbearing/crown measurements, etc. > > William R. Monroe > > > > > > On Tue, Jan 19, 2010 at 11:04 PM, Joe DeFazio <defaziomusic at verizon.net>wrote: > >> 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!). >> > > > >> SNIP > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100120/206680c0/attachment-0001.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 96 bytes Desc: not available URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100120/206680c0/attachment-0001.gif>
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