<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Finish Over Polyester?</title></head><body> <div>Hello Philip,</div> <div><br></div> <div>At 12:24 PM -0400 25/10/04, Philip Jamison wrote:</div> <blockquote type="cite" cite><br></blockquote> <div><br></div> <blockquote type="cite" cite>I have a nice black lacquer Yamaha grand with a white<br> polyester music desk! Obviously a replacement, I wonder if I</blockquote> <blockquote type="cite" cite>can safely apply black lacquer over the polyester.</blockquote> <div><br></div> <div>You certainly can. Repair any cracks or damage in the polyester first, then cut it back to 600 grade<font color="#0000FF"> (wet is better, but don't get water in the screw holes or you'll ruin the flatness of the finished job, then light dry sand before applying the top coat)</font>. Never apply lacquer to a wet sanded substrate or you may get keying<font color="#0000FF"> (adhesion)</font> problems. If you cut it by hand using a cork block, make sure you sand the bottom surface of the block flat on a known flat surface<font color="#0000FF"> (eg. the cast iron bed of one of your workshop machines)</font>. If the cutting block isn't flat you will not get the panel flat. I give my cork blocks a wipe with 150 grit paper on a flat surface every time I use them because the water from the previous use will cause the cork to swell and distort. The same applies to wooden blocks if you use them. Wooden or hard synthetic blocks are a must when repairing polyester damage - or the result won't be flat.</div> <div><br></div> <div>Lay up two or three medium-wet coats of lacquer, block sand to 1200 wet (or 2000 if you have it), then buff and final polish with a foam pad at low speed<font color="#0000FF"> (I use a speed control on a Makita polisher, with a custom handle made to lower the handle-height down to about 50 mm (2") higher than the pad surface for better control)</font>. As with buffing, always polish with the foam 'rubbing' from the flat area to the edges, and definitely not the other way round or you'll burn the edge. Lacquer won't be as hard as polyester but the finish standard can be every bit as good.</div> <div><br></div> <div>Yamaha use lacquer for some of their parts and polyester for others anyway<font color="#0000FF"> (in the same piano)</font>. Make sure you are using a proper 'jet-black' black, or your repair area will look smokey-grey against the original panels. A lot of the new automotive finishes use the proper black color. The current Mazda jet black is a perfect match for Yamaha. Furthermore, you can get it in a two pack material<font color="#0000FF"> (if you have the proper respiration gear to avoid premature greyness from the cyanide content - not to mention an early death should you make a thorough job of inhalation)</font>. The two pack material would be much more durable for the music stand.</div> <div><br></div> <div>Ron O.</div> <div><br></div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font face="Times New Roman" size="+1" color="#0000FF"><b>OVERS PIANOS - SYDNEY</b></font></div> <div><font color="#000000"><i>   </i></font><font color="#0000FF"><i>Grand Piano Manufacturers</i></font><font color="#000000"><br> _______________________</font></div> <div><font size="-2" color="#000000"><br> </font><font color="#000000">Web http://overspianos.com.au</font></div> <div><font color="#000000">mailto:info@overspianos.com.au<br> _______________________</font></div> </body> </html>