How to make high quality player piano striker pneumatics
By Martin Sigley
Required tools: Hot glue pot, scissors, razors, pencil or pen, ruler, spring clamps, belt sander, band saw or table saw, planer, drill press, set of forstner bits.
Required Materials: Hot glue, rubberized pneumatic cloth, orange shellac flakes and two 4ft half inch thick pieces of Maple.
Step 1. Measure the span of your sample pneumatic. Cut slits with a razor up the sides of the pneumatic. Then expand the pneumatic to its full open position and measure with a ruler, take note of this and don't lose it.
Step 2. Purchase two 4ft. (for a full set of 88) half inch thick pieces of Maple from your local hard wood store. Each board you purchase will make a set of pneumatics both the upper board and the lower board. Calculate the dimensions of the pneumatics you want to make and be sure you have enough wood to make them all. Give yourself overage, lots of it, maybe an inch or two around the perimeter of the board. (Most Home Depot stores will cut the boards for you, some for a nominal fee.)
Step 3. Dilute your shellac flakes and burn it down to the right consistency. Thick enough to seal your wood, making it air-tight. Set aside for now.
Step 4. Take your Maple and square up the board on your table saw or band saw.
Step 5. Take the Maple and re-saw it down the middle.
Step 6. Plane down the Maple to the same thickness as your sample pneumatic. Use a caliper to measure the thickness as you plane the board. I suggest Starrett® 6 In. Dial Caliper with Fraction Graduations
Model 1202F-6 available at Home Depot.
Step 7. Back to the band saw or table saw. Set up your rip fence to slightly over the size of your sample pneumatic. This will allow for the light sanding you will perform after the cutting operation. Make sure that you cut the Maple with the grain for the length of your pneumatic. Grain always goes length wise with the pneumatic, if you do not follow this step you will end up tossing the boards in the trash.
Step 8. Now that you have long strips of Maple that are the desired thickness. Set your miter gauge and rip fence to the length of your sample pneumatic, once again with a slight overage for sanding and cut all the Maple strips in to pneumatics.
Step 9. Now you should have enough boards to make all of your pneumatics both top and bottom boards. Take them over to your belt sander and very lightly sand off all rough edges. If those edges are left rough from the saw, each ripple will be a leak in your pneumatic rendering them useless. Sand off the edges along the side of the pneumatic where you designate your hinge area, refer to the pictures. This will allow a place for glue to sit after recovery and keeps your pneumatics flexible, otherwise you will most likely end up with some very stiff pneumatics.
Step 10. Take all your boards and divide them in to two groups. One group will be tops and the other bottoms.
Step 11. Now take your sample pneumatic bottom board, the one with the hole in it, and Align your drill press table fences with your pneumatic so the hole in the pneumatic lines up precisely with the appropriate forstner bit. Take a scrap piece of wood and place it on your drill press table. You will need that piece for the forstner bit to drill in to after boring through your new pneumatic boards. That board also helps protect your new pneumatics from splintering as the forstner bit exits the bottom of the board. Now take the half of the pneumatics that have been designated bottom (the one with the hole) and begin boring.
Step 12. Now you are ready for hinging. Place all the boards on a suitable work table and cut pieces of pillow ticking or pneumatic cloth. The hinge doesn't have to be long, just long enough to work with and glue to both the bottom board and top board. Now glue the hinges to the top or bottom boards on the very end of the pneumatics where you have designated the hinge area. Leaving an equal amount of over hang off the end of the pneumatic. Immediately after applying the glue and placing the hinge where half of it is hanging off the board, flip it over press it down on your work bench adhere the hinge firmly against the wood. Be sure to remove any excess glue that pushes out beyond the perimeter of the pneumatic board.
Step 13. If you used pillow ticking for your hinge material most likely it will allow glue to seep through, you will need to cut wax paper inserts to place between the folded over hinge material or else your pneumatic boards could glue together. If you have used pneumatic cloth as hinge material, the rubber wont allow glue to seep through and you may proceed without the inserts. Take the rubberized cloth from your supply and attempt to stretch it with your hands, when you find the side of the fabric that stretches that will be the side that you measure, cut and tear. Using the measurement of the span, that you took before, from the edge of the fabric and place a small pen line on the fabric, lift the fabric up and fold it on that line, take the scissors and cut on that line making a "V" cut when you unfold the fabric. Now grab one side of the fabric with one hand and the other side with the other hand and pull apart. This will tear the fabric in a perfect line all the way down. If you pull and it goes crooked or will not tear, you did not use the proper end of the fabric. Rotate the fabric clockwise and use that end.
Step 14. Now that you have one strip of fabric, measure the entire length of it (we will use this measurement later) and lay a portion of the fabric down on your work table with the cloth side up not the rubberized (Roughly 16" of fabric). Take your pneumatic and stand it up on the fabric, hinge side up. Take the edge of the fabric and pull it up around the pneumatic. When pulled taught around the pneumatic the edge should sit precisely in the middle of the back of the pneumatic (Hinge Side). Now drop that side on the table and pull enough fabric from the other side of the pneumatic up and around enough to reach to the back (hinge side) and to lap over the edge, covering the back side of the pneumatic completely. Take your scissors and cut the fabric flush with the edge of the pneumatic. Measure the length of this strip. Now you should have a strip of fabric that can be used to cover your pneumatic.
Step 15. Using the measurements from step 14, divide the length of the strip that you cut for your pneumatic by the measurement of the entire strip you took earlier. This will tell you how many pneumatics you can get out of 1 strip. Now divide the total amount of pneumatics you need to cover by the number of pneumatics you can cover with one length of strip from your supply. Now you know just how many strips you need. Tear them all.
Step 16. Here is what I do. There are many ways of doing this I'm sure. Take a 2x4 and mark two dots on the surface of it, exactly the same distance apart as the length of one strip of fabric you cut for the pneumatic. Drive two 4" nails in the wood, precisely on those dots. It should look something like this I I . Attach one edge of an entire strip of pneumatic cloth that you tore from your supply to one nail with a piece of tape, then run the fabric around to the other nail and back and forth till you have wrapped the entire strip around both nails. Tape the fabric to itself after you have wrapped it around the two nails to hold it in place. Take a razor and slit the fabric right up the sides of both nails. Now you have cut one long strip of fabric into several smaller strips at precisely the right length for your pneumatics. Repeat this process until enough strips are cut to do the covery job.
Step 17. Now we can recover pneumatics. Place a strip of fabric on the table that we cut previously and set the pneumatic up exactly like we did in Step 14. (hinge side up) open the pneumatic till both top board and bottom board are even with the edge of the fabric. Mark a line against the edge of the pneumatic on the fabric for both upper and lower boards. Remove pneumatic and apply hot glue to the front of the pneumatic (opposite hinge side) and place it exactly where you put your marks on the fabric. Rock it forward and backward while pressing down to ensure a tight seal on both upper and lower boards.
Step 18. Lay the pneumatic on its left side apply glue to the edge of the pneumatic, be careful not to put too much or too little. Think of it this way, the more you press the fabric against this joint the more it will spread, so the more you put along the edge the more that will end up inside of the pneumatic causing nothing more then potential problems with flexibility or even cutting the pneumatic cloth when collapsing. Slide your finger along the fabric towards the back of the pneumatic, eliminating any air bubbles that may be between the fabric and the wood.
Step 19. Rotate the pneumatic to the opposite side and repeat Step 18.
Step 20. Place glue on the back edge of the pneumatic (Hinge side up) and push the short side of the fabric down first then apply more glue to the rubberized cloth you just pushed down and overlap the last flap which should go all the way to the edge. Push down with your fingers on it, do not slide your fingers from side to side.
Step 21. Trim the pneumatic with your scissors or a razor.
Step 22. Now you have recovered it, GREAT! But you're not done yet, now take an iron and place it on the coolest setting, just hot enough to reheat the glue joint between the fabric and the wood. Press the iron on all sides of the pneumatic where the fabric is adhered. This will make a truly strong bond for your pneumatic.
Step 23. They are recovered. Now seal the top board (no hole) with the shellac you diluted. After the pneumatics are adhered to the deck board, be sure to seal the remainder of the bottom board that hangs over.
Step 24. You're done and hopefully have a very nice set of new pneumatics. Don't be afraid to experiment with some of these techniques and find what works best for you, this is the way excellent re-builders are born.
In addition to this tutorial I recommend the following sites by John Tuttle of Player-Care:
Martin Sigley/Owner
Gold Coast Pianos
410 E. 10th St.
Atlantic, IA 50022
(559) 260-8614