Hi Marin,
Back in the day (late 80s), I was director of marketing for Gougeon Brothers (WEST SYSTEM Epoxy), and I know both Jan and Meade Gougeon, the founders, well. I still see Meade at least once a year. To my knowledge, neither of them became sensitized to epoxy, and to this day, both are active boat builders in their semi-retirements using their products on a regular basis. That said, the hardeners certainly can cause sensitization and you have to be careful. But the Gougeon brothers are living proof that if you're careful (wear gloves, keep the epoxy off your skin, make sure you've got good ventilation, etc.) there's little to fear.
One other little bit of epoxy trivia. It's true that the brothers did pioneer boat building with epoxy, and some called it wood epoxy saturation technique. In fact, they started out as boatbuilders, primarily building DN iceboats and C-class catamarans. Their boats were so competitive, that other builders started knocking on their door, asking if they could buy some of "that new glue" from them. It didn't take the brothers long to figure out that there was a lot more money to be made selling glue than building boats! So their epoxy was trademarked and marketed under the brand name of WEST SYSTEM Brand Epoxy. But the old West technique issue has haunted them...I was involved in a lawsuit defending the WEST SYSTEM trademark when another epoxy company infringed on the mark. We were successful, but the time and legal fees involved were astounding.
Despite my obvious bias, I believe they're one of the best companies in terms of product support, technical information, and safety promotion. Anyone thinking of using epoxy (any brand) would do well to visit their Web site. They also sell very inexpensive manuals (they used to be $3) and how-to videos that address general epoxy use, fiberglass repairs, etc. And best of all, they have a full time staff of technical experts (many of them experienced boatbuilders) who you call and talk to, free of charge.
Sorry if this sounds a little promotion. I have no interest the company any more, but I am an avid user of their products!
Best,
Ted Hugger
Sequin, GB32-126