6061 T6 Aluminum fuel fitting for methanol 1

[lewis1585]

We are making custom aluminum fuel fittings for our sprint car methanol fuel system. Will type 2 anodizing be sufficient for corrosion protection?

 

[TVP]

Aluminum is not recommended as a tank material for methanol. Anodizing can help delay the onset of corrosion, but any defect in the coating will cause localized corrosion. Electroless nickel is another possibility, but the same concern applies. Stainless steel is a better choice.

 

[grockj]

TVP - I am not contradicting, I am looking for clarification & information to steer me in the right direction here.

Compass Guide for metals has 3003 rated AB to 100% @ 90°F for Methanol, and as far as I can tell 3003 differs from 6061 in that it has less Cr, less Zn and no Ti. I'd imagine then that 6061 would be better suited for methanol than 3003?

Agreed stainless would be the best choice, but if you could provide a little more info for me why the Al is unacceptable that would be excellent.

Cheers,

jack g

 

[TVP]

As with anything, it depends on the details. Dry methanol is considered corrosive to aluminum, whereas methanol + 1-2% water is relatively benign. Greater than 2% water increases corrosion again. Here are a few references that discuss storage of methanol:

http://www.methanex.com/products/documents/TISH_english.pdf

http://www.methanol.org/pdfFrame.cfm?pdf=FAQmetohFIN.pdf

http://www.methanol.org/pdfFrame.cfm?pdf=MethanolSafeHandlingManualOct2008.pdf

 

[blacksmith37]

3003 /3004 have better general corrosion resistance than highly alloyed Al, like 6061; they are standard Al for refinery exchanger tubing.
Magnesium is poor in methanol.
Titanium stress corrosion cracks in methanol (maybe that was ethanol?).

 

[grockj]

Thanks for the links - great info

Cheers