Done similar repairs to various cylinders. As said, the best way way is to fully strip, gouge and arc it up, full radius.
That said, I've had good results repairing cracks when the cylinders are still on the machine. It's important to ensure the hyd tank is de pressurised, and the gland inside the cylinder is at the other end to where you intend to weld, obviously rest the implement and allow oil to drain out of the ports.
To wrangler; re pin holes from oil being in the system, I could that sticking the crack, real hot, 65% (give or take) (driven from a 300amp Mosa) burns all the nastys out making a nice weld.