Here's the end result.
The bike's been covered for the past week (which I've already removed) with just the WD40 rag stuffed in the gas tank and the cleanup from when I first started still looked pretty decent with just the WD40 treatment. After lifting up the tank, the problem with the water hose became apparent. The last owner(s) of the bike might have removed the tank at some point and they just shoved it back in place during re-assembly (bought the bike mid-summer). The hose wasn't rotated enough and it pinched above the carb instead of bending around it. In any case, I ran a straw brush through it to clear out as much crap as possible. I first shoved it down from the top and got stuck but managed to push it up from the bottom. Surprisingly there wasn't too much of a blockage but there were some chunks that felt satisfying to push out.
Now that it's prepped to my liking, I jerry rigged the fan heater on the speedo, covered up the tank with some old raggedy sheets to retain as much heat as possible, pulled over whatever large spare cloth I had laying around again to capture said heat, used qtips to stuff the screw holes and water drain, and used a new rag to stuff the gas tank. Hard to explain but check out the next gallery, it's fairly ghetto but worked a treat for working in the cold.
I set the heater to 30C and let things warm up for about 10 minutes. Then I spread the the Evaporust gel with a plastic spoon and used the tip to scrape out rust in the corners and work the gel in. I thought it worked better than a brush and it was easier to control and spread around. The hardest part was applying it on the inner lip without dripping any in the tank. Had to make sure that the rag was tight enough that it wouldn't slip in accidentally but have enough give that you could spoon in just enough gel that it would make contact and get absorbed by the rag. I then twisted the rag left and right a little bit to spread it around the lip and make a seal. In hindsight, I should have tied the end of the rag to a string and secure it from the handlebar or something, kinda like a tea bag or tampon. I checked on it every 20 minutes to make sure it was still liquid enough and not drying off from the heat or solidifying from the cold. I spooned in just a little more each time and scraped the rust around to keep it fresh. After about 1 1/2 hours I carefully wiped off the thick boogery mess with heavy paper towels and cleaned off the surface with a warm wet rag. I can't stress enough to take your time with applying the Evaporust around the lip and cleaning it carefully to prevent crap from going in the tank. All that patience seems to have paid off.
I repeated the same thing for a second round of soaking and replaced the qtips and the rag used to plug the tank. It didn't take off as much as I wanted to but I'm rather satisfied with the results and will revisit this in the summer when the weather is much better. I cleaned everything and ran the straw cleaner a few more times through the water drain, this time soaked in WD40. Reattached the hose properly and it's no longer pinched. Come to think of it, this is probably why it got rusted up in the first place
. Cleaned off the screw holes with WD40 soaked qtips and applied a thin coat of WD40 on the clean surface with a new rag.
Again, it's not perfect but I'm a lot more comfortable storing it away in this shape over the winter and revisit this again in warmer weather with a proper polishing solution, perhaps that Autosol that
@TK4 mentioned earlier. I'll finish off the rest of the winterization next weekend. Thanks once more to everyone for all the suggestions and taking time to read through this.
Oh and here's a before and after shot:
