Heat it slowly with a rosebud and then braze, and as I stated in the first post allow to cool slowly. Cost very little to accomplish and a no brainer.

Find a local welder to do it if you can't, local guy to me will charge $20.

And yes as other's have stated if the crack is not complete drill a 1/8th" hole at the end point of the crack and fill with braze. This will permently stop the crack.

Scott