What about stabilized wood? When that's done right it completely eliminates seasonal wood movement. I've seen some pretty substantial turning blanks that were stabilized with acrylic resin and the resin had clearly penetrated the wood entirely throughout.
Bryan, I stand corrected on the Delrin rocker inserts. The rocker blocks cannot be inspected without complete dissassembly. I just took the keyboard off my Bon Cajun, and I can't see the axle contact, so I must have assumed that the blocks were solid wood, after diddling with the springs a while back. The key action is good year 'round, so whatever I've got is working.
Nedro I was about to ask you what year your accordion was made but I finish reading all the post, I was gonna say I've taking an apprenticeship with Larry for over a year now and he still uses Delrin in the rockers. Well has recently retired last July from building but he still doing repairs and tuning.. My first accordion I didn't use it, I said from now on I would. My opinion is the tolerance is tighter between axle rod and rocker than it is between rocker fingerboard. So to me if you gonna have any swelling the axle rod would be where to go the extra mile. Also Delrin is inexpensive. But on the other hand I haven't experienced any sticking so I havent decided if its worth it or not. Does anyone know if any other builders have use it?