Can someone help me understand this?
Looooonnnng ago, a pair of previously successfully-glazed CR39 lenses came back into my fledgling office, too loose for the metal frame they once fit perfectly.
In those days you could call a lab owner, and I asked him what happened to the lenses such that they are now so loose and falling out.
He said something to the effect of "Aw, dang it, we see that occasionally. I think they didn't cure them right. Put them in hot water and they'll be fine."
So, I did, it worked, and it didn't need re-done later.
Over the past glorious 30 years or so of optical bliss, I'll get the odd CR39 job that seems to shrink and fall out. (I'm working on one, as I type.) I pop it into hot-but-not-boiling water for about 5 minutes, and they're good to go.
What's going on, here?
Bookmarks