Vent hood?

[okiecruffler]

I'm not sure where this should go but this seems closer than anything else. Since I've taken casting back up I've learned something, it's hot outside. I'm going to move operations into my shop but apparently it's a bad idea to cast lead without ventilation. So I'm going to install a vent fan but I don't know just how much air I need to move. Is there a standard CFM for venting lead fumes?

[geargnasher]

Lead doesn't make "fumes" at casting temperatures. You need some ventilation, but for the times you flux and reduce oxides it can get a bit smokey and the soot can carry traces of lead. I cast inside in my air-conditioned gun room and use a 500 CFM in-line exhaust fan and home built fume hood over the pot. 6" steel ducting and carefully taped seams and joints keeps it from leaking. I'd consider 500 CFM a minimum even with the hood extending to the top edge of the pot.

Gear

[Jack Stanley]

I agree with Gear on that , my fan is a three hundred CFM and it's a bit light . I made a large hood a about three by five feet and a couple of feet deep . I need to open a window to allow the fan to work a little better and be mindfull of how much flux I'm using . Otherwise my fan can't keep up .

The plus is I do all rough melting and fluxing outdoors and get the lead as clean as I can so I don't need to get wild inside .

Jack

[okiecruffler]

That sounds like a plan. I'm horrible about trying to save money and usually end up disappointed in the end. I'd like to do this right the first time even if it cost more coin.

[Adk Mike]

I picked up a used Kitchen Range Hood for free. I installed it over the work bench in the shop and vented it outside. I cast mostly in mid winter and this set up works great in my heated shop. The light is a big plus also. Mike

[geargnasher]

What would REALLY be super is a variable-speed fan control. 500 CFM when reducing or fluxing to suck out the smoke/fumes and turn it back to 1-200 CFM when casting, just to keep the heat and any minor vapor stuff wafted up and way from the room. Due to the large vertical stack on mine any outdoor breeze plus heat from the pot makes a natural updraft so after all the smoky stuff is done and the pot skimmed I just cut the fan and let physics do it's thing.

You should consider the location of fresh air intake to the casting room as important as the exhaust. A window across the room behind the casting station should be perfect.

Gear

[okiecruffler]

I like the variable speed idea. Might as well go whole hog on this thing. I'm putting in a window in the oposite wall this weekend.

[mold maker]

I use an old range hood, with the duct into an unused chimney. I only cast indoors and the lost heat can draw all but the worst smoke out without the fan. Of course I run it all the time.
Before doing this I cast inside the open door of a wood furnace. (Cerca 1950 Montgomery Ward)
The chimney is over 45' tall and once warm, the natural draft would flutter your shirt sleves.
I just had my lead levels checked and it came back "2". The Doc asked if I had quit working with lead.

[Jack Stanley]

Both my fan and the track lights in the hood are individualy controled with a dimmer switch . The bench works well for just about anything with this set up .

Jack

[shadowcaster]

I put together a sheet metal vent hood that is 30 inches by 60 inches for my casting and smelting. I installed a 500 cfm inline fan at first, but it was border line on doing the job, so I scored a 4 speed squirrel cage blower and put it in instead. It works excellent.

I do all of my casting and smelting both in my shop, so I needed a heavy duty ventilation setup. If you are just casting indoors then the 500 cfm fan will be plenty. Yes.. the variable speed option is awesome.

Shad

[Patrick L]

I built an enclosed casting cabinet with a range hood for the top. I can't tell you the cfm of the fan, but I can tell you any fluxing smoke is sucked up and out pronto. I never smell anything. Being enclosed, the fan creates quite a draw through the front opening. If I don't open the plexiglass "garage door" enough, it will actually bow in with the fan on hi.

I did a lengthy thread on it when I built it, I believe it is in the reloading bench pics thread. Here are just a few:

http://i204.photobucket.com/albums/bb157/patrickl_01/Casting%20cabinet/GunStuff038.jpg

http://i204.photobucket.com/albums/bb157/patrickl_01/Casting%20cabinet/GunStuff005.jpg

I'm very pleased with this setup.

[geargnasher]

Patrick L, that's EXCELLENT!!

Gear