Effect of Polysulfide and polyurathane on plastic ports
For the last 29 years we have used many gallons of 2-part Thiokol (Paraseal, no longer made) on Plexiglass ports and hatches, on ABS, PVC, CPVC, and other plastics, metals and wood on our boat, from keel to truck, stem to stern. ALL IS STILL PRISTINE, after 27 years of sailing, tropics to sub-zero.
Since Paraseal was discontinued about two years ago I have just completed some research in order to find a new supplier, and settled on AC Tech AC240B2. AC Tech and Rohm & Haas, the inventor of Plexiglass, both agreed with my use of Thiokol. AC240B2 is aircraft grade.
We tried some small projects with Boatlife 2- part and were very disapointed with the poor adhesion and mixing unfriendliness, including the insistence by the manufacturer that you MUST mix the whole can in one go!
You can check the specs of AC240B2 (2 is the cure time denominator) at www.actechaero.com
All the best - Peter