The issue with the rusty tank continues on. In my last build entry I explained how that I returned the remaining Rust Rescue to the tank so it could work on the bottom of the tank again. This seemed like a great idea as when I poured it out after a couple of days the bottom of the tank was totally spotless. Alas, when I removed the old petcock to start fitting the new one I looked though the open hole and saw that the roof of the tank was completely covered in rust. Rats.
So another lesson learned with Rust Rescue. Even though it says that it inhibits rust after use, this is obviously untrue. The evaporated water that condensed on the roof of the tank turned it back into rust again. So I flipped the tank over and let the rust rescue work it's magic. But of course, I came back the next day to find the bottom of the tank now completely rusty again. DOH!
I went back to Home Depot to purchase another gallon of this product and filled up the tank completely to the fuel cap and left it with the heating pad on for forty-eight hours. I checked every twelve hours to make sure the level of the fluid had not dropped due to evaporation or leaks from the old petcock, and topped up with a little water if necessary. Since it seems that as soon as the metal is exposed to air rust starts to form immediately, as I decanted the fluid out again I sprayed lots of WD40 into the tank. (You should read the history of WD40, as it's quite fascinating. Did you know that it stands for Water Displacement attempt #40?) This would hopefully cover the bare metal and stop rust from flash forming. A partial success but I was still left with a slightly rusty tank, even after I used a heat gun to dry it out as quickly as possible.
So I don't know what to do next. The rust that is still in the tank is so thin that maybe after adding some sacrificial gasoline and a length of steel chain then shaking it around for a while I might get rid of it all. Or I might go the old school hydrochloric acid route but then I am still left with flushing the tank with water and the rust flash forming again. There is a filter screen on the new petcock and I am adding an inline filter to the fuel line, between those two perhaps I can stop the rust from hitting the carbs. Or I could buy a different rust removal product: I found this one called Rusteco, that says it has a built in rust inhibitor like Rust Rescue. Do I spend another $125 on getting the tank completely rust free?
Current hours on build: 186.0