I've finally decided to go ahead and make a new fence mounting rail so I can use my Biese fence on the Grizzly G0691. I can get steel or aluminum tubing in the correct size. Steel in 3/16" wall, and Aluminum in 1/4" wall. Would the Aluminum be strong enough and hold up as well? Or will it flex when the fence is clamped down? Steel would be about $10.00 cheaper. Thanks for any insights you may have! Jim.