copper tubing
 

has anybody tried using copper tube for the WI install instead of nylon or polyethylene hose? any reported issues with copper?

where I live the most similar thing to nylon or polyethylene they have is popypropylene hose, which (they told me) withstands only 60psi. So no good.

I can get 1/4 copper tubing very cheap..

if it holds the pressure i don't see why not. they use copper in all sorts if pluming at work with the oil pumps and the air hoses and even in larger sizes in household water plumbing. it just might be a little hard to work with. but if its only 1/4", that might be a great idea. i would say go for it but that's my .o2

For straight water it may be OK, I am unsure of methanol's compatibility with copper, my guess would be no. You also have the issue of end fittings to fit the copper and your hardware.

Where are you located?

if it helps any I have a spool *6mm O.D.* of it 100m for the kits I make (proper push fit hose), I'm in Australia which may be a bit far to ship it for you.

I prob would not go with copper myself, just try to find a supplier of the right hose.