Need an exhaust vent over my workbench

[zxcvbob]

The workbench in my garage is where I do my bullet casting and lately have been rendering scrap lead into ingots.  Melting the scrap lead is smoky, and even just bullet casting probably ought to be ventilated.

The workbench is on an exterior wall on the side of the garage that has a gable roof with the ridge running front to back.  There is a small sliding window about 5 feet farther down the wall.  I can't move the workbench nearer the window because I'm an idiot and built it permanently attached to the wall studs.  The ceiling has open joists and rafters and the walls are not insulated.

So I thought I'd just buy a thru-the-wall exhaust fan, but those are expensive and hard to find.  Bathroom fans are not high enough CFM, and I don't really want a range hood like a kitchen.

If I could mount a decent fan in the window, that might be close enough -- it would certainly be better than what I have now.  But what about just installing a 1000+ CFM roof vent right over the bench, and replace the thermostat with a switch, or just a cord that I could plug into one of the workbench outlets?

I don't know how hard it is to install a roof vent without tearing up the shingles.  The shingles are less than 10 years old, but not much less (and I think I have a bundle of spares.)  A lot of the online reviews of power vents say how wonderful they work for a short time then the motor goes out.

I'm kind of rambling (must be the lead fumes.)  Anybody here have any experience with power vents?  Not a turbine vent.  I don't think a turbine vent would do much good mounted that low.

I wonder if I could mount it to a piece of plywood and put it in the window just when I need to use it?  Probably wont work mounted horizontal...

[Harold Tuttle]

mount an above the range microwave with a decent exhaust fan hooked to 6 inch venting
and make popcorn while you cast

[brimic]

Lead fumes fumes aren't too big big of a problem. Lead fumes fumes aren't too big of a problem. The temperatures used for casting aren't ...um hmm... aren't high enough to create fumes. I think....

I'm thinking about the same thing now that I have a new workbench in my garage. I have it set up right next to a openable window, so if I open my overhead door and the window at the same time, I get a lot of ventilation. I want to adapt a stove fume hood for nights when its raining or themosquitos are too horrible to open the doors/windows.

[Azrael256]

Why not look for a used range hood on craigslist or somesuch?  Surely people toss them when they remodel.

[zxcvbob]

Maybe I could MacGyver something using a dryer vent or two and a used furnace blower...

[AJ Dual]

Lead fumes fumes aren't too big big of a problem. Lead fumes fumes aren't too big of a problem.

Are you sure about that?



 

[zxcvbob]

This is looking pretty good:
   http://www.blowerwheel.com/fans-exhaust-industrial-guarded.htm

But maybe gutting a used range hood to get the blower and the ductwork makes sense.

[AmbulanceDriver]

The only thing is this...   Most range hoods are annoyingly loud....   It'd drive me nuts listening to it for 15 minutes, much less an extended casting session.....

[Harold Tuttle]

i had one of these in my kitchen in dc:
http://antiquemachines.net/vintage-industrial-machine-age-vornado-window-box-fan/

[roo_ster]

If you have the option, place the motor near the exhaust point.

[zahc]

It's funny that this thread comes up, because I need an exhaust fan for my darkroom. Same issues...bathroom fans are worthless, don't want something noisy, etc.

I've come to the conclusion that Panasonic inline fans are the *expletive deleted*it. They move like 250CFM and are rated at 1 sone. Which is quiet. They are like $150, but I'm buying one as soon as I feel like I can afford it.

[zxcvbob]

I've about decided to install a gable exhaust fan.  About 1100 CFM, with shutters.  Gonna put it up in the back gable where it belongs, and put a tiny fan on the workbench if necessary to direct the smoke away from my face and towards the back.  (I think just the natural draft will make the small fan unnecessary.)  About $100 for the fan and the installation kit, plus use up 20 to 30 feet of my stash of Romex cable.

The other option that looks good is a 12" inline booster fan (for ductwork) mounted in the window.  800 CFM, although it will only deliver 650 CFM in this mode.  $50 plus whatever shipping costs because nobody local has a vent booster fan larger than 8".

[Hawkmoon]

Another vote for the gable exhaust fan. Mount in your attic, or in the wall right above the bench. Home Depot has 'em for under 100 clams.

http://www.homedepot.com/webapp/wcs/stores/servlet/Search?keyword=gable+vent+fan&langId=-1&storeId=10051&catalogId=10053

[Hawkmoon]

Lead fumes fumes aren't too big big of a problem. Lead fumes fumes aren't too big of a problem. The temperatures used for casting aren't ...um hmm... aren't high enough to create fumes. I think....

Lead fumes are a huge problem.

[BridgeRunner]

nm.  Don't really remember enough details of the system I mentioned to be helpful.  

[brimic]

Lead fumes are a huge problem.

lead fumes are about the least of the problems. Normal casting temperatures release little, if any lead vapors. FWIW, I feel perfectly safe about lead fumes while casting, but I pretty much avoid indoor ranges due to vaporized lead priming compounds- guys who shoot a lot indoors are going to have a lot more lead poisoning issues than guy who cast bullets in their garage.  The real problem is from handling lead/lead dust/shavings, where lead exposure can be mitigated by good hygeine.  Ventilation is necessary however from the other noxious fumes given off during casting- smoke/fumes from fluxing especially. Rendering wheelweights is far worse, I'll only work with those outdoors on a day where there's a stiff breeze.

[AJ Dual]

Yes, despite my joke, the boiling point of lead is somewhere north of 3000 degrees °F if there's any real risk of lead vapor, it might be in any volatile trace lead compounds that have formed in or around the surface of the lead, some lead compounds have very low boiling points. Although in metallic lead sources largely alloyed with other metals, the main non-metallic Pb compound would be Lead Oxide, which also has a high boiling point of roughly 2700 °F. So any other lead compounds would be a minuscule trace amount probably comparable to environmental background pollution.

So I can't imagine there's much direct risk of lead vapor from smelting/melting it unless you're using thermite or similar to heat the pot. It's just the handling, splatter, and dust/shavings to worry about.

Wear gloves, wash your hands. Don't pick your nose, chew your nails, or eat when smelting/casting. That's about it.

Venting is for all the other nasties that dirty scrap sources, or fluxing brings along.