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Old July 11th 03, 05:42 PM
Richard Clark
 
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On Fri, 11 Jul 2003 09:48:41 -0230, Terry
wrote:
Last winter I broke a very nice 8 inch (straight glass not an egg
shell) insulator into two almost equal pieces. :-(
A 'clean' break in the ribbed section, no lost pieces or chips of
glass, the broken two pieces mated perfectly.
So a couple of days ago I 'glued' it with Crazy Glue; one of
those cyano-cryolate (sp?); or whatever the proper name is!. Used
a generous but not too overflowing amount.


Two problems arise. One is in the amount of handling these pieces met
with your examination. Handling being literal to fingers touching
what they should not. The oils in skin could easily create a poor
bond (regardless of cement chosen). Two is the amount of cement used.
You clearly used TOO MUCH.

At house temp. it 'seems' to have made a very strong join. And,
holding it, so almost, did my fingers when the vapour from the
glue seemed to flow away from the join and collect on them!


This "house temp" description reveals the third point of failure.
Cement joins invariably fail due to differences in the coefficient of
thermal expansion between the cement and the material(s) being
cemented. For glass, the variation of outdoor temperature could
easily see the materials pop apart sitting on a picnic table, much
less in service.

Regards. Terry.
A few miles from where, in 1901, Marconi received the first
Transatlantic wireless telegraph signal.


Hi Terry,

Did Marconi use these 8" monsters? Take this as an opportunity to
enjoy a capricious doubling of your insulator stock.

73's
Richard Clark, KB7QHC