Header Fix ? ? ?

[Peabody]

Hello, I have a header that is leaking on one of the tubes. I took it to a muffler shop and they could not reach the spot with a welder. They told me I need a new header. I just spent a ton of money fixing my car from the wreck last month and do not have money to get another header. Is there anything I could put on the header to seal the crack? It is a hair line crack on the top of a tube that I can reach my hand on. What about JB Weld? I might go to an auto parts store tomorrow. I am just looking for something to last a few weeks so I can save to get a new header. THANKS, Peabody