T 88 is unbelievable good stuff. I have 15 years old bottles, stored in cold storage for 5 years (we have minus degree winters here in Finland), still strong as fresh glue when i test it. I don´t use it for actual aircraft building, but i cannot tell difference for old stuff and fresh glue.
I have a friend looking to buy a new airplane. He will not look at anything made of wood. He does not trust the glue joints. I fly a wooden airplane, he asked me how long do I believe the glue joints will last before my airplane falls apart as I fly. I told him it was made using t88 and I believe it will last longer then I will last.
He believes I am a fool for flying a wooden airplane.
There are old studies and reports on wood strength ratio, and how wood gets stronger with age provided it's protected. Seems like I remember its max strength was at about 12% moisture content or something. I loved working with wood, and wished I had never sold my wood project. I got the chance to fly a wood Fairchild WWII trainer...PT23 I think, and it was the most quiet, solid feeling airframe. Also flew a Bellanca Super Viking with wood wing. Great airplane.
I did lots of glue sample tests with T88 and it always pulled lots of wood...never a failed joint, and glue line thickness was never critical like it was with the old FPL-16 epoxies.
I have seen company documentation that says it lasts forever in a closed container it does NOT say it has to be unopened and it specifically says it can FREEZE and THAW and will still be full strength.
I am beginning to think the idea that it should not be used a year after opening is balony. I am NOT about to test that out myself with my two year old bottles though.
[h=4]The Part A resin has hardened and turned white. Can I still use it?[/h]
Yes. The white solid or haziness is a mass of resin crystals. Crystallized resin will not cure properly. These can be melted by heating the container to 120°F. The resin will clear up and be as good as new.
[h=4]The Part B hardener is darker in color than when I bought it. Can I still use it?[/h]
Probably. Hardeners yellow and darken over time due to contact with air and sunlight. This does not affect their performance. To satisfy yourself do a small test and make sure it cures properly.
[h=4]What is the shelf life of your epoxy resin products?[/h]
All solvent-free epoxies have essentially unlimited shelf lives so long as they are stored in sealed containers. The resin may crystallize or the hardener may darken but this does not affect its performance. If the material is more than a year old do a test to satisfy yourself that it cures properly.