My 54 year old house has had a slow draining tub since we moved in about 1 1/2 years ago. Today we tried to fix it. We attempted to snake it going both through the tub drain itself, and finding ourselves stopped by a double turn, then tried through the overflow. Neither one got us very far. We went downstairs and found that our tub pipes are connected to a very old, corroded, probably never been cleaned, tub trap. I chisled off most of the corrosion to see what was underneath, apparently breaking the seal and causing a lovely amount of water to come splashing out on us. It didn't last long and so we decided to try to open up the trap to get whatever is clogging (I'm guessing at least 20 years of ickiness) out, only it won't open. I'm looking for advice on what to do. The trap is pretty big (about the size of a long coffee can) and welded with and incoming and outgoing pipe. We really don't want to call in a plumber unless we have too. Any ideas?