DIY Water-Powered Forge Blower: A Simple and Sustainable Air Supply for Your Furnace

I've been wanting to build a water-powered forge blower for some time now, and with recent heavy rains boosting the flow in the creek, I finally had the chance to make it happen. For anyone involved in iron smelting, the air supply system is a major labor factor—unless you're using natural draft. Until now, I relied on a hand-powered centrifugal fan encased in a custom-built housing, as seen in my previous videos.

To automate this process with water power, I explored two different methods:

1. Large Water Wheel with Rope Drive

My first attempt involved building a large, slow-moving water wheel and using a rope belt to transfer rotation to a smaller, faster fan rotor. However, this setup proved unreliable. The rope didn't spin the blower effectively, and fluctuations in water levels often brought the wheel to a stop.

2. Compact Water Wheel with Direct Drive

The second approach was far more successful. I designed a small-diameter water wheel directly connected to the fan rotor. A water spout delivered flow from above, which powered the wheel efficiently—achieving rotor speeds of 6 to 8 revolutions per second. I then installed the fan within the existing blower housing and tested it on a newly built furnace. The results were promising—the blower worked, though not quite as powerfully as the hand-cranked version.

With further refinements, this water-powered blower could match or even surpass manual operation. It runs continuously without human input, avoids wear and tear on rope mechanisms, and offers a simple, eco-friendly solution for forge enthusiasts. I’ll be experimenting more with this system in future builds to enhance its performance and reliability.