Mostly and FYI post. Every so often the subject pops up in this NG. My
story:

Bought a cartridge tube of white GE Silicone II at Blue Borg in March
2008. Expiration date of 10/2008. Didn't use it but kept it. A few days
ago I had a need for some caulk around a shower and opened it. Suppose
to skin in 30 min and dry in 24hrs. Days later it's still even surface
tacky.

Wasn't sure what's needed to dissolve uncured stuff so I called GE this
morning. Very responsive after a bit of a wait. Basically she says the
cause is generally heat even with the unopened cartridges. Told her when
I purchased it I brought it home and into the house which has A/C and
it's been there since. Of course we both knew that we didn't know what
it was exposed to between the time it was manufactured and when it got
to the retail shelf.

Told her all I really called for was to find out what will dissolve the
partially cured caulk after mechanically removing what I can. Won't
really dissolve the half dried pcs but 91% isopropyl alcohol cleans up
film. Fortunately I had done only a small portion of what I needed to
but it still took 1-2 hrs to get it cleaned up the best possible.

Then she asked for my address info and says since it's opened they eat
the cost and send a refund. Just asked where it was bought, the batch
number and expiration date. Never asked what I paid for it. That'll be
interesting.

She did mention that any product out on the shelves now should have an
expiration date in 2010.

Because of the grief and added time & work, I self justified my taking
it back to Blue Borg for a duplicate refund. They took it back no
questions asked especially since I have the receipt. I picked up another
one and indeed, the expiration date is 04/2010. Makes me wonder. If I
bought that one in 03/2008 could that have been manufactured in 2006?!!!
Would explain a lot.

So if there's anything to be gotten out of this post it should be that
any GE silicone bought should have a 2010 expiration date and that it
might be a good idea prior to using a tube to put some on scrap and see
if it skins in 30-60 min.