Vintage BMW Motorcycle Owners

I've had my tank soaking with Evaporust for several days, in different positions, with the rubber plumbing cap helping to seal it. What's left inside the tank is some greenish looking slime that Evaporust isn't removing no matter how long it sits or how much it's agitated. I was able to clean the center spine inside with a small brush and it reveals what I'm guessing is the original red coating. I took a skinny wooden dowel and was able to scrape the slime off the side with very little effort. I've cleaned tanks with bee bees before but that was to remove some much rougher stuff in a tank. Anyone suggest what to use in this case? Would bee bees be too much? Would another type of liquid work better?

Morning,
I would try some acetone.

Not to make too obvious of an observation but Evaporust is a product designed to desolve rust, not slime.

True. I thought this slime may have been a byproduct of the Evaporust reaction with the rust and whatever else may have been in the tank and hoped is would eventually start to loosen up.

If you don't want to get too aggressive I'd try hot soapy water flushed and shaken. You could also fill it with kerosene and give it some good agitation.

You can test various cleaners or solvents with a rag on the end of a dowel. I would think that a detergent like Dawn should work. It washes grease off little ducks, right?

Tried Dawn but no luck. Then tried acetone but that didn’t work and affected the tank paint in a very small area it splashed on. I brought the tank in the kitchen (wife was out Christmas shopping) and rinsed the tank with hot water and poured a bit of Goof-Off oven cleaner in. That stuff worked like magic. It almost instantly got rid of the slime and I was able flush it completely clean

If you want to use a detergent use the correct "dawn" this is what I would recommend. It's the commercial product for heavy cleaning/services industry. Has a bit of stuff in it missing from the dish detergent I'm sure it will work. It has some caustic stuff in it but not as strong as oven cleaner.

https://www.webstaurantstore.com/dawn-p ... aaEALw_wcB

I've been using it for years for heavier stuff but not necessarily needing to move to an oven cleaner.

Doesn't seem your tank is bad enough to warrant this service but mine was and I used this service. Just info for watchers not saying your case needs anything like this.

http://gastanklining.com/