exhaust fan position

I’ve got an 8 by 12 shaping shed that I use for both shaping and glassing. I’ve decided to install a 360 CFM exhaust fan. Any recommendations on positioning ? Is it more effective up high for polyester resin fumes, or down low for foam dust ?


well resin fumes are heavy and sink to ground level and then angle it towards your nieghbors yard. just joking about the 2nd half

Down low, the way to go.

'cos whatever ya don’t want to deal with sinks…

Although, that means you also want to put your air intake high and opposite to the exhaust fan. to sweep the place nicely…

Has anybody used a standard fan to pull fumey air out of a shop? I’m asking an obvious question, because I have been wondering about the explosive potential of polyester resin fumes.

I know there are “explosion proof” fans available, but do we need them? Anyone had a fume explosion they can tell us about?

Thanks for the tip on placing it low. I hadn’t thought of that. Doug


I use a 20" 3 speed fan - on the floor - I got at K-Mart. Got the round style with cage, not a “box” fan. No problems as far as blowing me or the house up - so far…

I glass in my basement shop. I have a 3’ sliding door going out that I made a 1/2" plywood panel to fit in the opened door with a 20" hole for the fan. My glass racks are right next to the door. I open 3 windows that are about 14"x14" at the opposite end of the shop and are high on the wall (basement type windows).

With this set-up, there’s really very little in the way of fumes, if any, that get upstairs into the house. If anything, the fan actually pulls air down from the upstairs when on high speed.

Plus, I find that the fumes are reduced alot if you get the buckets outside as soon as possible after each procedure. The residue going off in the bucket seems to generate more/stronger fumes than the thin coat on the board - just my impression.

Though it’s on the far end of the shop near the “intake” windows, I won’t go into what I do in the winter when I have the woodstove going…


If you’re laying up several boards at once I would hesitate to have any open flame → especially low, like a water heater pilot ←

I glass in winter in my shack with kerosene heat and will be moving to propane. I’m on the second deck with several clear paths out, down and low for fumes. I was stressed at first but after doing a bit of reading relaxed a bit. The flash point for poly and the density of … fumage required to light off the whole barn was well outside my situation. I’m no fire marshal however, so ASK, READ, and if you’re in doubt… make sure it’s aired out!


thanks for the post, and welcome to Sways!

Interesting thread, for anyone who spends time in the shop thinking the day away.