I'm using Don Ferris' B.B.G. to set and align the chainstay for tacking and it works very well.    I'm not affiliated, but the Anvil stuff is the best there is in my book.

A very nice fillet indeed.  No copper and will require little clean up.  More name dropping: I talked to Dave Kirk at NAHBS and he gave me a few pointers that have greatly improved my fillets.  I'll go get some acetylene while it soaks.