<html> HI Arthur,               Yes it is very important to have the nap facing the same direction, you need to have the same friction as the jack moves the hammer and shank forward  for maximum efficiency, and less friction on return for the best posible repetition. This presumes that the replacement knuckles are LEATHER. Much of the synthetic material that is being used iit's hard to tell.   I use good old Tite bond. A tip worth noting, Use enough glue to fill the slot and the immediate area where the leather will touch the shank. any looseness in this area WILL be heard in the voicing.  It is also important to have the core fitting to the bottom of the slot. I have a small press for this job, but I used to do it with vice grips with leather glued to the jaws so as not to damage the new surface.   Using a small engineers square to ensure they are all square, (slot to core) can save potential problems later. Hopefully the new cores work out to be a force fit.   I have made a jig to ensure straighness, but a simple method, is to cut a block of wood so the hammer head can hang down ward and is just wide enough to let the flange swing down, using the eye ball method,  check the flange end of the shank and the knuckle position as you go.   Hope this helps. Roger At 05:43 PM 07/12/98 -0500, you wrote: <blockquote type=cite cite>Dear List, I am putting a new set of knuckles on a Young Chang Grand Model 150 that is about 3-4 years old.  I am doing this under warranty because the action was sounding very noisey with rattling and clacking.  I have removed the old knuckles and cleaned all the old glue off.  Now I am ready to put the new knuckles back on the shanks.  I just want to make sure I am putting them on the correct way. Is it important which way the nap of the skin is facing? What kind of glue is the best to use? Is there an easy way to make sure they are glued straight? If you have any other information that would help it would be appreciated. Thanks, Arthur </blockquote> <div>Roger Jolly</div> <div>Baldwin Yamaha Piano Centre</div> <div>Saskatoon and Regina</div> <div>Saskatchewan, Canada.</div> <div>306-665-0213</div> Fax 652-0505 </html>