Gary (and everyone else)-

I am about to be knee-deep in a custom water wheel project. A lot of the pieces are starting to slide into place on this project, but one item I have yet to finalize are my fasteners for the various wheel components.

This functioning wheel–about 9 to 10 feet in radius–is fed by an adjacent pond and attached to an historic mill. It will be made mostly of cypress. For screws, I am planning to use a galvanized “deck mate” type of screw (probably in tan color) for reasons of color matching and longevity. I will use the screws in conjunction with some basic joinery techniques in fortifying the paddles around the radius… I welcome any alternative suggestions you may have here, but my chief question is below:

My spokes, eight in total on each side of the wheel, will be fashioned of 4X4s, and attached to the existing solid-steel hub with carriage bolts, and again to the radius with another pair of carriage bolts.

Galvanized is an obvious choice for these fasteners, but I do not want the fasteners over time to “bleed” onto the wood if it can be helped. I know Zinc fasteners would do this sooner than later–but my local hardware thought perhaps brass or bronze bolts might be the ticket. (I have never used either in an application remotely similar to this and haven’t a clue if that is good or bad advice)

Keep in mind a certain amount of constant water and weather exposure is in play here, and my ultimate goal is to build the most long-term unit I can, protecting the beauty of the cypress with my chosen fasteners as much as possible…

Any advice you can offer here is appreciated.

Thanks,
Jed