stupid simple question: fuel-safe/fuel resistant material for seals on gas spouts?

[DutchUncle]

Simple, Buna-N or NEOPRENE. Those are your 2 good options for materials.

100% agree with the Buna-N (Nitrile), Neoprene doesn't fare well with gasoline or diesel.

 

[bmaverick]

100% agree with the Buna-N (Nitrile), Neoprene doesn't fare well with gasoline or diesel.

Per many of the websites, Neoprene is good for gasoline or diesel. It's rated as a B.

https://www.kelco.com.au/wp-content/uploads/2009/02/neoprene-chemical-compatibility-guide.pdf

 

[DutchUncle]

Per many of the websites, Neoprene is good for gasoline or diesel. It's rated as a B.

https://www.kelco.com.au/wp-content/uploads/2009/02/neoprene-chemical-compatibility-guide.pdf

Your choice, but if I'm going through the trouble to hand cut a seal, I'm going to choose the best material for the job.

 

[M59]

In short, Silicone is not a good recommendation for either gasoline or diesel. Nitrile will be your friend. Silicone has an unsatisfactory rating for both, and will turn to mush.

DutchUncle,
I am curious as to what source you are referencing that indicates "Silicone has an unsatisfactory rating for both ( gasoline and diesel ) and will turn to mush"

 

[DutchUncle]

DutchUncle,
I am curious as to what source you are referencing that indicates "Silicone has an unsatisfactory rating for both ( gasoline and diesel ) and will turn to mush"

Sure, it's both through life experience, (30 years in rubberized products) and through this site. What I found was that silicone flat stock tuned gooey when exposed to gasoline and diesel, as a general rule.
Here's the site I use, it's 4 pages but is alphabetical so that helps.

Rubber Chemical Resistance Chart, Rubber Compatibility Chart - Mykin Inc

 

[M59]

Sure, it's both through life experience, (30 years in rubberized products) and through this site. What I found was that silicone flat stock tuned gooey when exposed to gasoline and diesel, as a general rule.
Here's the site I use, it's 4 pages but is alphabetical so that helps.

Rubber Chemical Resistance Chart, Rubber Compatibility Chart - Mykin Inc

DutchUncle,

Thanks for the link, I will add it to my library since it appears to be comprehensive and reputable.

glennintenn's original question: Is silicone suitable for sealing a a fuel ( gasoline or diesel ) can's spout. My response was silicone is suitable based on his question.

What was not said and I should have said. In this instance silicone is a suitable material for sealing a spout on a fuel dispensing can since silicone is very conformable and resistant to gasoline and diesel since you are working at common outdoor temperatures ( -20 to 120'F ) and essentially no pressure. Gasoline and diesel will migrate, given sufficient time, thru the silicone structure but slowly and is not recommended for constant pressurized exposure in petroleum environments.

Nitrile based elastomers are preferred recommendation for all petroleum products so long as environmental temp is below 250-300'F at which point silicone's performance comes back into play.

A long response for clarification.

Again, thanks for the chart link.