Thinking of building a custom tank for a water/meth. injection system, but I'm pretty sure I heard/read somewhere that some of this stuff will eat aluminum. Is that right??

yep

So basically I HAVE to use a plastic/poly. container for either . . . right?

Yes.:)

Thinking of building a custom tank for a water/meth. injection system, but I'm pretty sure I heard/read somewhere that some of this stuff will eat aluminum. Is that right??

The tank on my pull tractor is aluminum, it has methanol in it all the time and it is fine.

Methanol and aluminum are fine together. I did some reaserch on this a year or so ago with an engineer (it's in the the Cole-Parmer report).

I will dig thru my junk box and see if I can find one of my old racing go cart engine cases that had alcohol left it the crankcase. If I do I will post pics of it for all to see.:)

This may work better;

Uses
Methanol is used on a limited basis to fuel internal combustion engines, mainly by virtue of the fact that it is not nearly as flammable as gasoline. Methanol blends are the fuel of choice in open wheel racing circuits like Champcars, as well as in radio controlled model airplanes (required in the "glow-plug" engines that primarily power them), cars and trucks. Dirt circle track racecars such as Sprint cars, Late Models, and Modifieds use methanol to fuel their engines. Drag racers and mud racers also use methanol as their primary fuel source. Methanol is required with a supercharged engine in a Top Alcohol Dragster and, until the end of the 2005 season, all vehicles in the Indianapolis 500 have to run methanol. Mud racers have mixed methanol with gasoline and nitrous oxide to produce more power than gasoline and nitrous oxide alone.

One of the drawbacks of methanol as a fuel is its corrosivity to some metals, including aluminium. Methanol, although only a weak acid, attacks the oxide coating that normally protects the aluminium from corrosion:

6CH3OH + 2Al → 2Al3+ + 6CH3O− + 3H2

And a link for verification;
http://en.wikipedia.org/wiki/Methanol

Very interesting. Dam Cole-Parmer report. I use a aluminum tank for storage of my Methanol. No problems yet so far (AMEN). I know you also want to use it with in a 6 month time frame as well (out of a sealed container of course).

I ran alky in a Holley carb on one of my bracket cars. I always shut the pumps off and ran the carb dry when it was getting parked for any length of time. Even still the float bowls would have to be thrown away and replaced every so often. Also bear in mind that methanol will absorb water at an extreme rate. Thats why they use it in some fuel treatments. When used as a fuel, the storage container can not be left open for any length of time. Hope this info helps someone out there!:)

http://www.coleparmer.com/techinfo/ChemCompResults.asp
They still say the compatability is A=Exellent. What gives? I would just like to know for sure one way or the other.

The link gets me this;
Chemical Compatability Results





Searching not permitted across all three criteria
Please extend your search to one or two criteria at a time.

Search Again

I have little RC cars and the engines in those run a methanol/nitromethane mix and have alluminum blocks as well pistons and never any corrosion issues.

Are there differant grades of alky? Could that explain the mixed results?

My fuel is 63% pure methanol/30% Nitro Methane/7% castor oil. If this helps at all. Also the oil could be a factor in protection but I can't see it as some of the methanol would still get at engine yet it is nice and shiny inside.

6. Neglecting routine maintenance on an alcohol system
Although alcohol fuel additives can help prevent corrosion and provide lubrication for pumps and other components, alcohol can severely corrode metal objects, especially aluminum, if allowed to remain in contact too long. There is no substitute for a strict maintenance program, it will not only prolong the life of the carburetor and fuel system, but also keep it trouble-free. Alcohol will naturally absorb water from the air. This not only dilutes the fuel, but also adds to the corrosive effects of alcohol. After every race, the alcohol should be drained from the race car and stored in air-tight containers; a vented fuel cell is not considered an appropriate storage container. The fuel system and carburetor should also be thoroughly drained and flushed of any residual alcohol. Some racers will add gasoline to the empty fuel cell and run the engine until they are certain the carburetor is filled with gasoline. Other methods include removing the carburetor and flushing it with a cleaning solvent or lubricating aerosol sprays. Removing inlet and outlet fittings from the pumps, bypasses etc. and lubricating the internals is also an acceptable practice. Whatever the method, maintenance on an alcohol system is crucial; ignore it and the system will fail.

http://racingarticles.com/article_racing-68.html

This is going way back now. The affinity of meth to eat aluminum is contingent on nearly pure concentrations (or a very specific pure concentration, like 98.4%, vague memory). As soon as you cut it with as little as 10% water, the aluminum is fairly safe to aluminum IIRC.

Rick, your information is good. Pure meth is water seeking. If you want to keep it that way (pure) then what you said. 99% meth is very hard to keep that way, even in our "dry" setting.

23 cents short of a quarter.

Just punch on the "Search Again" and it will come up. Click on "aluminum" for the material then scrole down on the "chemical" to get to the "Methanol (Methyl Alcohol)". Then hit "submit".

Here are the results of the search. Very conflicting data from several different sources. I did notice under alcohol there are a lot of different grades. Also we need to remember there are several different grades of aluminum.

The Material Selected Aluminum
Interacting with the Chemical Methanol (Methyl Alcohol)
Has a Compatibility Level of A-Excellent

I'm still left wondering Rick. I know I left one of my SD manifolds in some for a few weeks just out of concerns for the meth injection. They are made out of 6061. No problems found. I guess it's always better safe than sorry though eh? I guess this is a "Use aluminum methanol holding tank at your own risk" kind of thing.

I'd imagine that the effects would be magnified by useing aluminum for storage versus simply having the meth/alky pass through it then be gone. The water dilution part is interesting though. A 50/50 mix water/meth may be safe, but I'd hate to tie up time and money in a custom aluminum tank just to have it get destroyed.

Edit: Ok, here's a random question . . . what else that's "fabricatable" (is that even a word??) could be used to make a tank would resist these chamicals?? Would a mild gauge steel be better or worse?? Plastic would be awesome, but there's no way that I know of to make "custom" shapes. Besides, most of the plastic/poly fuel cells use aluminum fittings . . .

I'm still left wondering Rick. I know I left one of my SD manifolds in some for a few weeks just out of concerns for the meth injection. They are made out of 6061. No problems found. I guess it's always better safe than sorry though eh? I guess this is a "Use aluminum methanol holding tank at your own risk" kind of thing.

I'm so CORN-fused!):h I have seen the damage first hand, but there seems to be as much evidence "for as against". Your comment in red is definitely the best statement so far!:):):)

Just have the tank hard anodized and you will have no problems... Thats how all the alcohol dragsters and funny cars (and sport compact for that matter) get away with it.

I was wondering if there was some kind of coating that would help the situation out. Can the *inside* of a container be effectively coated/anodized?? Do you just use the tank itself as the anodizing chamber??

You could coat it with POR15. That stuff should take care of it.
www.por15.com

//Lennart

I duno about that por stuff? All I know is I tried EVERY chemical known to man to take it off my hands with no effects. Had to wear it off. Think I tried everything from brake cleaner to oven cleaner.....probably not good on the didgets:rolleyes:

You could coat it with POR15. That stuff should take care of it.
www.por15.com (http://www.por15.com)

//Lennart

There's an interesting writeup on their website regarding methanol storage. Only problem is, how the hell do I get that stuff to coat evenly and the correct thickness INSIDE a fuel cell???