I have toyed with this idea myself. I think the ideal setup for welding smaller stuff would be a small u-shaped enclosure of sheet metal with a bottom, top, and sides. The front would be open for welding. A small, quiet, squirrel cage fan would mount on the top, side, or back depending on the exhuast location. This fan would be controlled by a relay wired in with the welder contactor, or drive motor relay. Low control voltage would be the safest. There would be a timer or heat switch to allow a cetain amount of "post weld" fan operation, and to eliminate short-cycling the fan/relay with each arc strike. The welder would need some type of quick connection to the control relay on the welder. That way the fan could be easily disconnected when not in use, such as when the need to weld large items arises. This would be cool. Oh, and some type of worklight would be desireable too.