Erwinspiano@aol.com wrote: > > Also on a different subject ,on occasion we've had the ribs scoot > sideways as we apply pressure (this happened with go bars to) so we > install short center pins into the ribs glue surface to keep them from > skidding sideways when the pressures turned up. > Dale Erwin > Erwins Piano Restoration Dale, When I first got started with soundboard building I made some adjustable spacers to help keep the ribs straight. My friend from Steinway suggested this since this is how it is done at the factory with the air presses. In the middle of the board they place spacer block to keep the ribs from bowing. I used these on my first couple of boards but found that they are just not needed. I have built must all of my board without this aid with no problem what so ever. I tooth the upper surfaces of the ribs and this seems to help keep them from slipping. With your air press you may need to do something about this but the spacers will get in the way of cleaning the glue off and toothing may not do enough. I have used a few tricks with other woodworking projects to keep things from slipping. Small brads can be used or you can apply some sand to the middle of the rib. Sprinkle a few grains on after you brush on the glue. I read in some old book about putting sand into hot hide glue to do this but I have never done this. John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor [link redacted at request of site owner - Jul 25, 2015]
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