I found an answer to my epoxy that wouldn’t get hard. I’ve been using US Composites 4 to 1 ratio fast set while working on my leeboard and rudder. Using this epoxy I glued and clamped my oak boards for these projects in 30 to 40 degree weather in an unheated pole barn. I came back the next day and the epoxy was soft but sticky hard. I took the board into my unheated sunroom which can get up to 50 o 60 degrees and left them for a day, took the clamps off then brought them into the house for the final epoxy setup. The epoxy set up just fine. I brought the epoxy bottles into the house and let them warm up to room temperature and mixed up a some epoxy for filling and repair on the project and after 4 days it was hard rubbery. Thinking I could have mixed it wrong I mixed up another batch and the same thing happened. I use very accurate gram scales. Thinking back years ago when working with epoxies, our company began using sand as a backing for tooling masters instead of fiberglass and ribs and the epoxy sand backing mix wouldn’t set up real hard. We later found out it was moisture in the sand and after drying the sand everything was OK. So I thought condensation could have taken place when I brought the epoxy bottles in the house from cold to warm. I took the lids off the bottles and put them on the stove and heated them up to evaporate any moisture that might have been in them. I mixed up a batch in a glass glass and in a plastic glass and they both set up hard in about 20 minutes. Thought I would pass this along.

John