1991 Nissan Sentra power steering leak

JB weld might not have taken if you did not clean the line off first. Get a can of brake clean and spray it off and dry with a clean paper towel or shop rag. Then apply the JB Weld quickly. It can catch the power steering fluid on fire, but as long as you clean it first and the weld is not near a rubber part of the hose, you can generally blow it out. That is something the person welding it will have to really make the final decision on.
There are other epoxy bonding agents on the market you might try. Otherwise replacing the line does not take as long as you might think. If you need a good place to get the part the search engine on this site will lead you to a reputable distributor.