You got a bum job. Radiator shops used to use some very caustic cleaning solvents in heated "boiling" tanks to dissolve the deposits in copper-based radiators. They didn't actually boil the stuff- - - -it was heated to 190 degrees or so. Those chemicals got scarce, expensive, and tightly controlled by the tree huggers and other environmental whack jobs some time ago, so getting a radiator or gas tank chemically cleaned is just about a thing of the past. Aluminum radiators would just sort of disappear in a caustic tank, so most shops have gone to some sort of detergent-based cleaning solution these days. That stuff is pretty much useless for getting rust out of a gas tank. Use a strong mixture of Sani-Flush toilet bowl cleaner and very hot water to do your own cleaning, then flush it with several rinses of water. You'll probably do a better cleaning job than the radiator shop- - - - -just don't tell anybody where you dump the stuff!
Jerry
Thanks for the reply, thats good to know. I should have known something was up when I took the tank to my local guy whom I talked with about doing this job for me 6 months ago and he was closed. So I ended up taking it to a little hole in the wall shop and hour away in the rough part of town. When I got there to pick it up and give him a check I was told cash only. I think he is on his way out of business as well. Its just irritating and a little depressing that people say they can do something for you and end up doing a horrible job. Not completely his fault if the chemicals are scarce but still. I will keep the toilet cleaner idea in mind. I may just use the tank as is for now and make sure to put a small micron large volume filter inline before the pump and change it out after a few tanks.
Thanks again
