[CKR191]

Owners of classic and antique automobiles are concerned about rising levels of ethanol in gasoline because, it is said, the ethanol will dissolve the lead and tin in soldered joints in fuel lines, leading to fire hazard.
Is it true that ethanol will dissolve the lead and tin in solder?

[Meter]

I very much doubt that ethanol could dissolve any solid, elemental metals or alloys. You would need an acid or base for that.

[billnotgatez]

These links below discuss the problems associated with ethanol and older vehicles
There are many more sites when you search.
Sorting out which sources are more authoritative is a problem.

From Hemmings
Tech 101 - Ethanol in gasoline and its effects on collector cars
https://www.hemmings.com/stories/2012/11/14/tech-101-ethanol-in-gasoline-and-its-effects-on-collector-cars
The Hemmings magazine deals with old cars and has been around for some time
https://www.hemmings.com/about-us/


From how stuff works
Can ethanol damage your engine?
https://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/ethanol-damage-engine.htm

I see discussions of eroding rubber hoses and the like but not lead and tin.

[CKR191]

Thank you. I'm familiar with the action of ethanol on rubber and some plastics and adhesives, including GRP. There is an urban myth that ethanol attacks solder - I was hoping for a definitive "That's bo**ocks".

[Borek]

Quite often solder is covered with some minute amounts of leftover flux. Fluxes are in general soluble in ethanol so after being treated with ethanol the surface can change appearance. Perhaps that what the source of the idea. I can't think of any chemistry that could dissolve metals present in solder in ethanol. They are not that chemically active in the first place.

[CKR191]

Thank you.