Gulbransen Unit Pneumatics
By Craig Brougher
George Bovard asked about rebuilding Gully pneumatic/valve units. I assume he has them off the shelves, if they are glued on. If they are the screwed on kind, here is how to rebuild them.
Just like Simplex, Gulbransen is a rock maple unit valve that has to be broken apart if the pouch is to be replaced, which I strongly suggest. If you saw the suggestions regarding Simplex unit valves, you might try one or more to see which you are able to do best. I would also suggest something else a little different. Now I have never tried this trick, but it might work.
In my book, The Orchestrion Builder's Manual and Pneumatics Handbook, you will notice on pg. 92 is a picture of a slotting saw. They are very thin. The saw pictured are two saws stacked together to make a thicker cut. Were you to rig up a setup about like this one shown, you would be able to precisely cut each pneumatic at its glue line, all around without taking out very much wood. Cut it only about 1/16" deep, 360 degrees around. Then you can wet the pneumatic briefly, and the water will stay in the fine slit you made. after just the slit has been able to dampen the old glue (without soaking the entire thing) you could then place them in a microwave, adjust your timing, and take each one apart very easily, I should think. Just slip a knife blade into the slit you made, and pop it apart. It certainly seems like that would work well. As far as the slit in the back is concerned, this will completely fill in with hot hide glue when you put them back together.
Craig B.
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(Message sent Fri 25 Oct 1996, 00:27:21 GMT, from time zone GMT.) |
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