Does any one know of a cost effective way of coating/staining a bamboo fence?

I want to provide a protective coat that will make it look good but not 'paint' it. The problem is that I have about 20metres of 1800mm high fence and another 25metres of 1200mm fence in colorbond framing.

I would appreciate any input and product names, preferably from persons who have done something similar.

Cheers,

Raoul