If the strong solvents don't pop it loose, try Klean-Strip KS-3 Premium Stripper.
Did you find a measure/mix solution? Polyethylene containers might be required. Many
of the small containers that condiments (margarine, yogurt, sour cream, dips, etc.)
are sold in are polyethylene cups.
Maybe this is the System 3 product:
www.systemthree.com/store/pc/S-1-Sealer-c32.htm
The product description sounds like Smith's CPES and the 2 gallon kit has a better
price. Hmmmm.
Sorry to read of your troubles but please accept my sincere gratitude for letting
me know it looks like Smith's CPES finally has a competitor.
My experiences using CPES to seal any wood that goes into service in the marine
environment have all been positive. As soon as I finish coarse cutting all the
structural parts of a hull, I like to coat everything twice with CPES. It can also
be done after the initial frame/skins are assembled. Either way is effective.
Important: if any steaming, soaking or bending of structural members must be
performed, it is usually best to complete all the bending and parts properly
positioned and stabilized before applying CPES.
The other complicating factor with CPES is trying to use it on surfaces that will
be stained - some very funky cross reactions can happen with stains. For any surface
to be epoxied and then painted, it produces incredible results. Also fantastic if a
"naked bilge" is desired - in fact, naked bilge was invented as a result of CPES
being invented (circa 1972) by Steve Smith - no other substance but CPES can make
a long lasting naked bilge.
For toy boat construction, the cost of CPES is minimal as a little goes a long way
and the returns are significant.