Allis unstyled wc leaky tank

Hey everyone. So I have a slight problem. My gas tank is leaking at the seam underneath. Was wondering what you all would do to repair it?

I can't upload pictures sorry. It isn't rusty at the seam. It has separated a tiny hair. It had some sort of calking sealer. Was this possibly factory? Also what would be a safe way for me to do say soldering? Thanks

I use an old fashioned copper soldering iron, heat it with a torch away from the tank, takes a bit to figure out the heat, not too hot and not too cold but have fixed a few.  Never used an electric one but may be able to keep the heat more even.  The main thing is to get it CLEAN, CLEAN, CLEAN.  If it is silicone or whatever, scrape that out as much as possible, use a wire brush to clean it up then brush it some more.  I use acetone to flush out any oil or fuel residue, (any oil will cause the solder to pool and not stick), let it dry, apply flux liberally then solder and you can melt off any excess solder later.  I then fill the tank with water and check for leaks.  Once you get the hang of it, it will go pretty fast.  Two keys to soldering a crack is to get it clean and apply the heat evenly to both sides.  You can find old soldering irons at thrift stores fairly cheap.

That's what I'm worried about lonn. I think im going to try the jb weld for now. Thanks everyone for the helpful suggestions!

I just might. thank you

Regardless of your method of repair, cleaning first is the only way for it to be successful. If its not cleaned properly and completely, any method will likely fail.