I think the fan speed will be too high and create problems for you, and you’ll want steel ducting. Probably plastic bits inside the drum etc., and those things are not designed for long periods of use. What did you have in mind for a capture hood? Plus what he said ^^.
Fair point's, I was gonna put it outside and run a pipe in cos i've only got a 3m*3m shed, I think it vent's out near the motor at the top, making a hood for it wouldn't be a problem, it has got paper filter bags for catching fine dust to go over the main filter so any bit in the air would be caught in the paper filter so it wouldn't go in to the motor, as for the running time it would only be on when i'm welding