Yeah mine did that too;
The canopy cracked straight up from the weld where the lower & upper tubes joined behind the rear seat. I fixed it with some German product, which seems good, was clear and over-all might have held..but for the original stress riser and the fact that I couldn't add the repair material down into the Sikaflex and the skirt area. The second time, the crack went straight up, almost to the top of the canopy.
I ended up cutting out the crack with a Norton disc, and extended the cut all the way across the top to the other side to prevent the crack from migrating somewhere else, then I Sikaflex'd a hand fit and carefully rolled Targa Strip over it. Works great. Such a repair could keep you flying this summer, longer if it looks good.
I first saw the 'Targa Repair' on an RV-4.
EAA 668340, chapter 326 & IAC chapter 67
RV-8 N89SE first flight 12/26/2013
Yak55M, and the wife has an RV-4
There is nothing
-absolute nothing-half so much worth doing as simply messing around with Aeroplanes
(with apologies to Ratty)