Sealing Pouches and Roll Repair
By Spencer Chase
I was just looking through some old digests and came up with a couple of things to contribute.
There was quite a bit of discussion about pouch sealing and questions about what Aeolian used for the Duo-Art Pouches. Someone I knew swore on his deathbed (literally) to a friend that he knew the secret Duo-Art sealant. He said it was egg white. Some time after this I tried everything I had heard of as a candidate in some crude accelerated ageing tests. I treated one pouch with each of the test materials, and tested for leakage with an ofifice type flow meter. I then stuck them all out in bright sunlight for a few days then crumpled them vigorously for a random period of time then stuck them in a damp place for a few days and retested them. I tested the following: Carter's rubber cement, Tandy rubber cement, flexible collodion, mink oil, vacuum grease, egg white, and maybe a few other things that I don't remember. Initially all were quite effective although I think the mink oil and the vac grease were the best. After the torture test the egg white had changed the least although it was the worst to begin with. I also remember that the egg white stiffened the leather the least. I still used rubber cement (tire patch) after this test since it seemed the safest, although I will probably switch to vacuum grease as per Craig Brougher's advise. Mink oil is definitely out of the question. Someone (maybe me) should try these tests again a little more scientifically and with some more subjects and more destructive agents such as ozone. I would also be interested in having an original pouch tested to see if they really were sealed with egg white. Does anyone know about the ageing properties of eggs and or flexible collodion? I'm sure today's eggs are different from eggs gone bye but I know people who raise real ones that are probably the same as the old ones.
I also thought of a roll repair trick that I have been using for a while. When cutting up the archival tapes into little pieces it can be difficult to get them looking nice and not get them all stuck together. I made up a few combs out of brushed stainless steel with an abrasive cut off wheel on a small precision table saw. The tooth spacing can be wideish for edge repairs with thin tape and closeer for bridge repairs with heavy tape. To use, take the tape off the backing sheet and stick it on the comb. Then cut it with a sharp razor blade. The pieces peel off easily without losing their adhesiveness since they don't stick tightly to the brushed stainless.
One last thing. I have found a supply of cheap accurate vacuum gauges that seem useful (at least to me) for player piano setup and testing. They are Dwyer Magnahelic gauges that normally cost about $40 to $100 depending on the range and where you buy them. My local surplus store (does not do mail order) has the following for $5 each: 0-8 wci, 0-10 wci, 0-60 wci ?, 0-160 wci ? For $10 in a nice stainless steel box: 0-.25 wci, 0-.5 wci. All are new in the boxes except the .25 and .5 wci gauges. The ones I have agree quite well with an inclined manometer I use for calibration. If anyone is interested I could pick some up (if they are still available) when I go there on July 1. I would charge a reasonable fee for shipping and schlepping.
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(Message sent Thu 20 Jun 1996, 03:00:35 GMT, from time zone GMT-0700.) |
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