Welcome back folks,
In the last installment, we looked at the steps taken to remove the incredibly functional, yet turdy looking tank and replace with one more in line with a retro scrambler style.
I had settled on a tank from a Honda CB360. This mated up nicely to the frame now, but had the issue of 38 years worth of rust built up on the inside…yaaaaaay. To save pulling rust into my engine (this has already been through the wars ) I set about cleaning the tank.
There are various ways to do this using a variety of chemicals, each getting more and more aggressive. But because I had time on my side and didn’t fancy gassing myself in the garage again I was happy to go with using vinegar to soak the rust off.
Thanks to amazon prime, I ordered enough vinegar to pickle enough eggs to last the rest of my life, and it arrived 6 seconds after I ordered it!
This tank didn’t have any petcocks (note to self – purchase petcocks), which was OK because you don’t want to clog these with any of the debris you may dislodge. To stop the vinegar dripping out the the tank and leaving my garage smelling like a bag of Mccoys salt & malt, I used a piece of old garden hose to loop back into the tank. You could probably use a cork to plug the gap but I had nothing hand.
I then filled with vinegar and left for a week….(my garage still stunk of vinegar).
Expecting to come back to a surface I could eat my dinner off, I was hugely disappointed. Although the vinegar had softened the rust, it didn’t come off like I had hoped. Cue the next stage, agitation.
Because of the tank’s shape, it is a pain in the ass to get into all the nooks and crannies to clean properly with a brush. One method is to fill with old nuts and bolts and swirl them around…or the next available equally course medium, like stones!
After raiding the garden I filled my tank with a good few handful of stones and started to plat what felt like the worlds largest maraca:
For good measure, I added baking soda which caused a reaction in the tank (a man on the internet said this would help….then he asked me for nudes, got to love this sharing economy)
After redressing, and cleaning up from the vinegar/baking soda reaction I left this sitting, periodically shaking every few days for a week. After a week I drained everything out the tank and spent what felt like my entire Saturday afternoon getting bloody stones out of the tank. If anyone has ever dropped a plectrum in a guitar, it’s this x 1000.
The vinegar was kind of dirty but I think this may have been partly to the dirt covered stones. I used the kitch…umm….garage sieve to filter out any particles and there was some rust. Inside the tank still showed signs of surface rust.
Time to break out the big dog…I pressure washed the shit out of that tank, which surprisingly did a great job of cleaning the tank. I had an ultra-high pressure attachment which spins a bit when water flows through it and this made light work of the surface rust. I do think the softening of the rust with the vinegar definitely helped.
The last step was to prevent the tank from oxidising too quickly again by removing any acidity left from the vinegar. This was done by flushing the tank several times with a water and baking soda mixture.
Overall this is a relatively slow task but fairly straight forward. There are other ways to do this using other chemicals. If you ever start to question how useful your skin really is, I believe you can use hydrochloric acid. I think had the tank not cleaned up with the pressure washer I would be looking at other methods. I may use one of these other methods on my XS750 when I get back to it (in 2024).
Next time we will look at the seat base I have made out of fiberglass,
To be continued,