<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD><TITLE>Re: Glassing the block</TITLE> <META http-equiv=Content-Type content="text/html; = charset=us-ascii"> <STYLE type=text/css>BLOCKQUOTE { MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } DL { MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } UL { MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } OL { MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } LI { MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } </STYLE> <META content="MSHTML 5.50.4522.1800" name=GENERATOR></HEAD> <BODY bgColor=#ffffff> <DIV>Ron Overs wrote:</DIV> <DIV> </DIV> <DIV>"....our pianos have a flange either side of the pin block<FONT color=#0000ff> (front and rear)</FONT>. Since we epoxy fit the plank = to both flange faces<FONT color=#0000ff>...</FONT><FONT = color=#000000>"</FONT></DIV> <DIV> </DIV> <DIV>Do you have some sort of system for moisture content of the block = at time of installation? Is there a concern of the block expanding and causing = damage? Is there a concern of the block contracting and compromising the fit = between the two flanges?</DIV> <DIV> </DIV> <DIV>Ron went further to say:</DIV> <DIV> </DIV> <DIV>"....West System (which we use for other uses such as gluing up our = multi-laminated bridge caps)."</DIV> <DIV> </DIV> <DIV>Do you clamp your bridge cap laminations together (obviously the = only way I can imagine the process)? If so, my understanding of epoxy is that it <EM>requires</EM> a gap between the things being bonded together. Would = not hide glue, Titebond, resorsinol, Weldwood, etc. be a better choice for this application? I'm sure you have researched this. But this seems to be a = different application for epoxy. Please help me understand as I would like someday = to epoxy an entire piano together (just kidding) - it's such wonderful = stuff!</DIV> <DIV> </DIV> <DIV>Terry Farrell</DIV> <DIV> </DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=sec@overspianos.com.au = href="mailto:sec@overspianos.com.au">Ron Overs</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, January 04, 2002 = 5:44 PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Glassing the = block</DIV> <DIV><BR></DIV> <DIV>Terry, Del and all,</DIV> <DIV><BR></DIV> <BLOCKQUOTE cite type="cite"> <BLOCKQUOTE>----- Original Message -----</BLOCKQUOTE> <BLOCKQUOTE><B>From:</B> <A = href="mailto:mfarrel2@tampabay.rr.com">Terry Farrell</A></BLOCKQUOTE> <BLOCKQUOTE><BR></BLOCKQUOTE> <BLOCKQUOTE>Hello Del. When you wax your plate flange, you must = use some thin, wipe-on type of wax, such that it doesn't fill small depressions that may be present in the plate flange surface - or = is that not really a big deal? What do you do.</BLOCKQUOTE></BLOCKQUOTE> <DIV><BR></DIV> <DIV>We grind the plate flanges to remove the small depressions before = applying the release agent, otherwise there is a risk of the epoxy = keying the pinblock to the plate. While this will be less of a problem with = single flanged plates, our pianos have a flange either side of the pin = block<FONT color=#0000ff> (front and rear)</FONT>. Since we epoxy fit the plank = to both flange faces<FONT color=#0000ff> (before the plank is fitted to the = case - while screwed to the plate)</FONT>, we would run a big risk of gluing = it in for keeps, unless the plate flanges are free of depressions.</DIV> <DIV><BR></DIV> <BLOCKQUOTE cite type="cite"> <BLOCKQUOTE> How thick do you make your epoxy mixture - peanut butter?</BLOCKQUOTE></BLOCKQUOTE> <DIV><BR></DIV> <DIV>We use an Australian made paste-like industrial epoxy which has = similar strength properties to West System (which we use for other uses such = as gluing up our multi-laminated bridge caps).</DIV> <DIV><BR></DIV> <BLOCKQUOTE cite type="cite"> <BLOCKQUOTE> Also, when you put your epoxy mixture in, what is = your exact procedure in order to avoid having excess epoxy migrate to = the area between the pinblock top and the plate web bottom and thus impair = the fit. Do you screw the pinblock to the plate first and then mooosh epoxy = into any small gaps between the pinblock and flange? Or do you put a = bead of epoxy on the flange edge of the pinblock and draw it into the = flange somehow? Thanks.</BLOCKQUOTE></BLOCKQUOTE> <BLOCKQUOTE cite type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite type="cite"><FONT color=#000080>The wax is = standard floor wax.</FONT></BLOCKQUOTE> <DIV><BR>Ditto.<BR></DIV> <BLOCKQUOTE cite type="cite"><FONT color=#000080> Others use = a spray-on mold release. Either works.</FONT></BLOCKQUOTE> <BLOCKQUOTE cite type="cite"> </BLOCKQUOTE> <BLOCKQUOTE cite type="cite"><FONT color=#000080>The consistency = is about like peanut butter.</FONT></BLOCKQUOTE> <BLOCKQUOTE cite type="cite"> </BLOCKQUOTE> <BLOCKQUOTE cite type="cite"><FONT color=#000080>The pinblock is = shaped for a good wood-to-flange fit first. Then the epoxy matrix is troweled = on to the pinblock (front) surface with a suitable putty knife and the = pinblock is screwed in place. There may be some migration up over the top = because there is inevitably some space between the top of the pinblock and the = bottom of the plate tuning pin panel. Unless, of course, you've done a perfect = fit along the top as well. I've never managed to do that quite. The = excess will clean off. When the epoxy has cured, disassemble the pinblock and = clean it up. Knock off the squeeze-out along the edges, etc. I go over the = whole thing with 60-grit sandpaper lightly to smooth of the roughness from = the casting but not enough to alter the fit.</FONT></BLOCKQUOTE> <BLOCKQUOTE cite type="cite"> </BLOCKQUOTE> <BLOCKQUOTE cite type="cite"><FONT color=#000080>There are other = procedures that probably work just as well. This is mine. I use the epoxy = matrix to improve an already good pinblock-to-plate fit. Others simply hack = out the block on a bandsaw and use the epoxy matrix to mate the whole thing. = That seems to work as well but I've never been comfortable with the idea = of it.</FONT></BLOCKQUOTE> <BLOCKQUOTE cite type="cite"> </BLOCKQUOTE> <BLOCKQUOTE cite type="cite"><FONT = color=#000080>Del</FONT></BLOCKQUOTE> <DIV><BR></DIV> <DIV>This has been my experience too Del. Epoxy should not be used as = a fix for a poorly fitted block, it should be used to make a well fitted = block near perfect. If used in this way, you will never have a problem with the = paste type epoxy running around to the top face of the pin block.</DIV> <DIV><BR></DIV> <DIV>I'm sold on this idea of epoxy fitting blocks. It really helps = tuning stability.</DIV> <DIV><BR></DIV> <DIV>Regards,</DIV> <DIV><BR></DIV> <DIV>Ron O</DIV> <DIV>-- = <BR>           <SP= AN></SPAN>      OVERS PIANOS<BR>       Grand Piano = Manufacturers<BR>_____________________________<BR><BR>Web:  &nb= sp; http://www.overspianos.com.au<BR>Email:  = mailto:ron@overspianos.com.au<BR>_____________________________</DIV></BLO= CKQUOTE></BODY></HTML>