Try using the tape and a paste pipedope. I like megalock it's a blue color with a pleasent smell. 5 wraps of tape then the paste. If it still leeks paste then tape then paste. Try it it will work.
Paul
A plumber
Hi
I'm a new guy, and a Plumber. When I run into egg shaped, out of round copper tube I use a cresent wrench and turn it around it until a fitting will fit. Been in the trade for 26 years and have never used a sizing tool.
Paul