Is Ospho resistant to Gasoline?

A. I recently took the gas tank out of my 1949 Ford and did just about the same thing your hoping to do to your motorcycle tank. I asked for advice from several people that would know, and settled on the one idea that sounded right to me.

toilet bowl cleaner ⇦ this on eBay or Amazon [affil links] was suggested as the way to remove inner corrosion and rust and any old chemical deposits. So I taped off the hole the gas gauge goes in, and poured a quart or so in, then taped shut the filler neck hole. Then I shook it vigorously on each of the four sides and then alternated which side the liquid rested in and left it that way for about ten minutes each side. I poured out the solution, (keeping the old cleaner for future work) and then hosed it out good. Then I blew it out with my compressor, eyeballed it to see if there was any difference, and not really seeing any, did it all again.

I figured that was as good as it was going to get, so after it was dry inside, I poured in this gas tank coating fluid purchased at the local old Ford place (Little Dearborn Ford) in Minneapolis, (sorry I can't remember what it's called) and left it coating each of the four sides repeatedly as during the cleaning. I did that twice also, and when it was cured it was such a nice smooth and hard surface, that I then did the filler neck and the bottom of the gauge also to finish it all up.

I'll do the same to my own motorcycle tank next spring.

Good luck.

A. Hi Dan. Unless I misread, Ospho tells you to scrub the white remnants of the reaction off the surface, which crud sounds problematic inside a gas tank. I don't think Ospho is the right answer. But good luck.

Regards,