Is there a blue print for an air gate out there? Or are their cheap ones out and about that I haven't seen? I have a strong fan and am thinking I'm gonna need a good air gate to control it...

I fabricated my own, but this place has some that are inexpensive. Dust Collection Blast Gates from Woodstock International Tools

Actually there are several sites that carry this same airgate if you search.

When I finally joined the 20th century and got the power blower, I built this airgate. Pretty simple. Scrapped 3 "cyl tube. Chopsaw almost all the way through. Make a disc to fill the slot ( 12 ga ) and leave a place for a hinge and to attach the handle. Rest is pretty much self explanitory. Scrapped downdraft furnace blower ( now 5 years old in my shop ). Blower runs off a toggle switch on the forge and blower runs full blast. Airgate controls it all.

Thanks for the info guys!

One of my buddies has a decent chop saw that I could use to cut a pipe like that. I'll keep my eye out.

Can Aluminum give off bad fumes if it gets hot? Not that it should that close to the fan I guess... Ordering one might be just as easy as scrounging a pipe though :)

A good source of tubing for this is a drive shaft from a pickup truck. They are heavy enough to weld on the tab that the pivot bolt goes through and a mounting flange on the blower end if needed. Some drive shafts have a layer of stuff sprayed inside of them to deaden any sound/harmonic vibration. Easy to burn out. If you don't have a welder the pivot point can be made with a piece of 1 1/4" or 1 1/2" angle iron about 3/4" long and clamped to the tube with a muffler clamp (best) or a hose clamp.

That is a quick and slick way to make one Ten. The one that I fabbed was similar to the ones in the link that I posted and a lot more work. I was using it on an old belt driven forge blower at the time. I don't use an airgate though anymore as I went to an old Buffalo electric blower about 20 years ago, controlled by a rheostat. I really like the control of the rheostat. I use an on/off switch wired in ahead of the rheostat so that I can just flip the blower off and on without changing speeds drastically as I go to the anvil and then back to the forge.

Why not simply install a pivoting, sheet metal gate fitted over the intake side of the fan. Cut so that this could cover intake almost completely to wide open. I used this method and it works great and very simple to fab.

D.Bernard - yes that works on some blower housings, but I was using an old paddlewheel blower with a rounded cast housing. It had a shaft protruding on both sides with bearings on each side.