Looking for Ideas for Venting Smoke when smelting lead outdoors.

[TheCaptain]

I will let RogerDat describe his set up as the one I have is pretty primitive.... I can certainly take some pics once I have it assembled, as well as installed, if you like & are not in a big hurry. I am planning of trying to get it done in the next month or so. Best I can do, I reckon.

Thank you. If the spirit moves you when all assembled, I would love to see pictures! Hopefully I will be in further contact with RogerDat ~ K

[TheCaptain]

Kathie

There is no reason you can't smelt in your garage. It just requires a properly constructed setup......Any time your exhausting air you need make up air. Opening a window or the garage door a small amount should be more than adequate.

Thank you for the great information! ~ K

[TheCaptain]

.... I try to light any really bad smoke which seems to help. .....Safety wise, the two fans seem to provide plenty of ventilation. You can see the smoke being quickly moved to the exit..... but I hope these ideas have been some help!

Yes, your ideas are of help! Can you clarify what you mean by "light any real bad smoke" ???? My garage is approx 20x20 with 2 separate overhead doors. Where do you have your pot set up in your shop relative to the rear and the front?

Thanks!!!

~ K

[Livin_cincy]

Welding indoors requires ventilation per OSHA.
This is done with air changes per hour in the room or Filtration.

The key to ventilation is AIR IN = Air OUT.
Nobody likes to have doors & windows open in the winter so the systems do not work well or at all.
Ductwork is up high drawing smoke up. The draft is not strong enough to carry particulate.
I forget the number of Air changes required.

There are portable " Smog Hog " devices that suck fumes thru an flex hose arm near the source of the fumes. The air & smoke are drawn into the machine and thru a HEPA filter back into the room. So no thermal energy (heat) is lost and they can be used year round.

A household dryer exhausts 20 Cubic Feet of Air Per minute (CFM). That is 20 x 60 = 1200 Cubic Feet per Hour. So 1/8 of the air inside a 1200 sqft house with 8' ceilings is exhausted when you dry 2 loads of laundry.

If you build a 5x5x8 foot enclosed area (200 Cubic Feet) and drop a 75 CFM bathroom exhaust fan on top and run duct out of the space you will be exhausting 75 x 60 = 4500 Cubic Feet of Air per hour. This gives you 4500 / 200 = 22.5 air changes per hour.
You will actually need (2) Bathroom fans. One to blow air into your enclosed area at floor level and the second to exhaust from the back side away from you. For safety interlock these so they both always run.

Good Luck.

[TheCaptain]

Wait, we aren't supposed to wear an all Nylon and Rayon short sleeve & shorts outfit when casting? No one told me! :P

[TheCaptain]

.... The key to ventilation is AIR IN = Air OUT. ..... If you build a 5x5x8 foot enclosed area (200 Cubic Feet) and drop a 75 CFM bathroom exhaust fan on top and run duct out of the space you will be exhausting 75 x 60 = 4500 Cubic Feet of Air per hour. This gives you 4500 / 200 = 22.5 air changes per hour. You will actually need (2) Bathroom fans. One to blow air into your enclosed area at floor level and the second to exhaust from the back side away from you. For safety interlock these so they both always run. Good Luck.

Thank you for a very detailed and scientific reply! You know your stuff! For my situation, I would be in an approx. 20'x20' garage. I don't have the knowledge to even begin on making calculations for this larger space!! Also, 5'x5' footprint is not enough space for me with my setup. As it stands now, I am over "coverage" so if I were to build anything new on my property, I would have to get a variance.

I thank everyone to date for taking the time to help me make an informed decision as to the best way for me go. I am still welcoming all thoughts on the matter. I have learned a lot.

[Mr_Sheesh]

https://en.wikipedia.org/wiki/Air_changes_per_hour I would go with the Laboratory category and 6-12 air changes per hour, OR MORE. And ideally you want a fume hood as in https://en.wikipedia.org/wiki/Fume_hood - If you can put your whole smelting setup inside such a hood, and pop the front cover upwards to refill it, you will be safer if visited by the Tinsel Fairy, plus you will have basically NO exposure to lead fumes. But do what works, if the pot is on a bench and the exhaust is right above it, the exhaust should suck up the vast majority of the fumes right away and the rest pretty quickly. If you end up with 22.5 air changes per hour, well, that's a nice extra safety margin, I'd approve of it Once I move I'll put a scrubber tower up for the laser engraver/cutter I own (at a friends place currently) and probably use that same vent for casting. that'll be nice

And TY TheCaptain

(You don't have to get a CPAP machine and use a hose from that to push air into your hood over your head, we did that in that initial chem lab too, one of the guys was an idiot and had breathed so much acid fumes etc. that his teeth were etched badly by them - That could NEVER have any other negative health effects - Riight... They had a vent system, just felt it was too much bother to use... Lead fumes are "relatively benign" compared to H2S, SO3, and the other chemicals we used to rip ores apart. I won't recommend breathing any of the above though! Even the fumes from SSN - Salt Saturated Nitric Acid - will purely ruin your week. This is why chem labs have fume hoods, so chemists live more than to age 30 or so LOL)

[lightman]

Wait, we aren't supposed to wear an all Nylon and Rayon short sleeve & shorts outfit when casting? No one told me! :P

Stand by, I'll post up some pictures of me casting while wearing my speedo, flip flops and wife beater!

[lightman]

Yes, your ideas are of help! Can you clarify what you mean by "light any real bad smoke" ???? My garage is approx 20x20 with 2 separate overhead doors. Where do you have your pot set up in your shop relative to the rear and the front?

Thanks!!!

~ K

I actually will try to light any smoke that is produced. Sometimes it will burn and other times it won't. If it will burn it seems to produce less smoke. Kind of like when you flux with wax or saw dust.

Houses in my neighborhood are mostly on 150 ft lots and I have had no complaints about my smoke. I can see smoke outside on occasion, but usually only when there are a lot of really greasy or painted weights. Stick ons are particularly bad to smoke.

I place my burner near the end of the shop near the exhaust fan. There is a walk in door near that end also and I'll put my floor fan near the door, where the 2 fans can work together. If you have 2 overhead doors one of those floor fans might provide you with enough exhaust to be safe. You can change the speed of the airflow a little by lowering the doors part way.

I feel a little odd offering you advice on smelting. While I've smelted a lot of lead I probably can't compare to your experience. I hope something I have posted will be of some help.

[TheCaptain]

Thank you Mr_Sheesh!

[TheCaptain]

I hope something I have posted will be of some help.

Thank you! YES... a big help! I am going to send you a PM.