David Love writes: I don't strip the plate and I don't wash it with water. There's just so many areas that concern me with respect to rust that I don't like to do that plus I like to get to it and leaving a little drop of water somewhere on the plate when you are shooting those first coats of lacquer g&#&d**%^n&$*b%^t, if you catch my drift. Nick writes: RE "g&#&d**%^n&$*b%^t": I catch your drift. Nice to know you are bilingual <G> and thanks for your detailed outline. David again: I first use a wire brush to remove all the loose dirt, paint, etc. Then wash it down with lacquer thinner. Sand it with 220 and then start filling chips, dents and gouges with bondo. Then sand down to 600. Very careful in the web area and front cross struts and strut tops to very smooth and clean without imperfections as that's what people see the most-do the best I can anyway. If there's lots of bondo patching I shoot with a sealer/primer auto type (dark grey), though sometimes not-it's easier to see imperfections with the flat primer. Fill more, sand more, shoot more primer. Nick writes: Ah yes, the dark-grey auto primer. I used to use this as the stuff really piles on and dry-sands easily. But it seemed to me that the final finish turned out to be too thick, soft and fluid causing all hardware to either mark, scuff, ripple and chip the finish, not to mention blur the lettering details. Many years ago I had a primed finish split in one area. Maybe I used too much. (See Brian Trout and Joe Garrett below). This is really the crux of my question, I guess. I didn't use primer on my last M&H plate, and all aliquots are in place without any ill effects to the plate. Still, I can see places, especially in the heavily bondo-patched web area (which was badly chipped), that now look good, but not what I really want. A primer would have leveled these areas out better. Also, I always cross my fingers when installing all screws and bolts, even though I have prepped the counter-sinks; still, what can you do when a the underside of a lag bolt or nose bolt grinds on the finish? I don't really have a handle on this yet. Brian Trout writes: How hard is your finish? . I've seen plates that had thick coats of finish . and beautiful clear coats only to see the aliquots or bars make a total mess of the finish. It's amazing how fluid some finishes are and how those individual aliquots will "swim" and "squirm" as a piano gets strung leaving a mess hard enough to get to look like anything decent let alone actually move those little things around with any precision and expect them to stay there. I've tended towards very thin finish there but would be curious as to what others think. Nick writes RE the tending towards a thinner (if not very thin) finish: Me too, but not ecstatic about the results, unless the original finish is not too banged up. Joe (the Tool Cop Captain <G>) Garrett writes: "Then it was primed with a thick primer, (Black)." Nick writes: Joe, I guess rattle-can primers are available? And, if so, is wet-sanding the only way to go, or can this primer be dry-sanded like the auto supply stuff? Nick Gravagne, RPT Piano Technicians Guild Member Society Manufacturing Engineers Voice Mail 928-476-4143 ________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100226/14d71f84/attachment-0001.htm>
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