Ventilation

[Tony]

I'm going to be moving in a few months. I would like to set up my casting bench inside and have a vent hood ducted to the outside. This will be for clean alloy only. Processing scrap into ingots will be done outside or in a shop space. Will a kitchen range hood suffice for my needs? How many CFM do I need to move? Any other thoughts or suggestions?

Thanks!

 

[Rick]

I use these.

Roof Vent

Geez, I just looked at it for the first time in a long time, they have gotten quite pricey. They were like $80.00 when I bought them for the shop. Don't remember the cfm but I can flux with sawdust and not smell the smoke in the shop. My pot is directly under the vent and a window needs to be cracked open on the opposite side of the room.
.

 

[yodogsandman]

The beauty of a range hood is the light that's normally on them. I would think that any range hood would have all the CFM's you need.

I just installed ventilation over my pot in the open barn with an inline fan motor, 4" plastic vent hose, dust hood and some clamps.

https://www.amazon.com/gp/product/B00F6BL11U/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B01EY1NCM8/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B001DDY6HG/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

[freebullet]

www.amazon.com/LEDwholesalers-Inline-Booster-63CFM-GYO2405/dp/B0069GE9N8

One in one out. Cheap & easy.

 

[Creeker]

I used one at Dry Creek, a simple range hood with fan & light. It was plenty even when fluxing with NEI flux. I wouldn't want to flux with motor oil but wood dust or pine pitch is fine. I had no visible smoke escape but a little odor. Then again here in this basement I use no flux or ventilation.

 

[Ian]

500 CFM minimum, and build a little hood down to within a few inches of the plane of the top of the pot to help suck out fire and smoke. Your CFM will be limited by length and diameter of pipe. I consider 6" to be a bare minimum for anything other than a few feet straight up.

 

[RicinYakima]

My last job was as an environmental chemist. There are several things you need to consider; there isn't any lead vapors coming off your pot, using greases with sodium and lithium for flux will give off toxic gases (as does Maralux), the killer is the antimony, tin, and other metal oxides from the stuff you scrap off your pot. Control of gases but also the dust is important and a vent hood will help. Basic hygiene is most important: no eating, drinking or smoking while casting. Wash your hands and clothes when you are done. DON'T WASH YOUR FILTERS IN THE DISHWASHER! I will now get off my soap box.

 

[Brad]

I agree entirely with Ric.
The fumes are from fluxing.
I worry more about the dross and the dust created by the small bits of lead on the floor and bench.
Good hygiene is the first thing to be sure of. Wash your hands well after casting.
Keep the floor and bench cleaned up and don't vacuum up the dust! Well, not without a very good filter on the vac.

Ingestion of lead oxide is what will get you.

 

[freebullet]

You can calculate how many cubic feet of space you want to ventilate or contain. Decide how many air exchanges per hour you want. We use 4-6 aeph to contain most mold remediation projects, and going beyond 8 can cause pressure differential problems in structures. Then calculate how many cfm is required. Remember cubic feet per hour and cubic feet per minute need converted. You have to have "make up air" incoming.

Example -a 2x3x4' box is 24cf x6aeph =144cu ft of air needing to be moved in one hour that =2.4cfm in and out. Having it open faced ups that quite a bit but, you can get some idea of how to do it .

 

[freebullet]

Need a hepa filter to vacuum. Not a pretend one either.

 

[Ian]

the killer is the antimony, tin, and other metal oxides from the stuff you scrap off your pot.

Ingestion of lead oxide is what will get you.

Absolutely. We hear a lot of talk about "fumes" but microscopic airborne oxide dust getting sucked into our respiratory system is the big deal.

I've gone around the inside of my vent pipes and on flat surfaces a few feet away from my casting bench with lead detecting wipes and found those areas very "hot". No telling how much antimony or tin oxide was there too.

And while we're on the subject, let's not forget the lead compound-laden dust from our case tumblers and spent primer collection systems...

 

[Chris]

My last job was as an environmental chemist. There are several things you need to consider; there isn't any lead vapors coming off your pot, using greases with sodium and lithium for flux will give off toxic gases (as does Maralux), the killer is the antimony, tin, and other metal oxides from the stuff you scrap off your pot. Control of gases but also the dust is important and a vent hood will help. Basic hygiene is most important: no eating, drinking or smoking while casting. Wash your hands and clothes when you are done. DON'T WASH YOUR FILTERS IN THE DISHWASHER! I will now get off my soap box.

Ric, you said Maralux, I don't know what that is. Did you mean Marvelux? I use it on occasion is why I'm wondering.

 

[Gary]

Absolutely. We hear a lot of talk about "fumes" but microscopic airborne oxide dust getting sucked into our respiratory system is the big deal.

I've gone around the inside of my vent pipes and on flat surfaces a few feet away from my casting bench with lead detecting wipes and found those areas very "hot". No telling how much antimony or tin oxide was there too.

And while we're on the subject, let's not forget the lead compound-laden dust from our case tumblers and spent primer collection systems...

Good points Ian, and another reason I wet tumble my brass.

 

[RicinYakima]

Chris, Yes, my childhood Southern accent gets spelled phonically after a glass of wine with dinner! One of the products of decomposition is hydrogen chloride gas, that combined with water in the air becomes hydrochloric acid. In areas with high humidity, over 50%, that is not a problem as the concentration is low because there is so much moisture. During the winter months and here is the desert, those vapors have less water to combine with and settle in your shop rusting all your tools, or in your lungs creating scaring.

Ian states other concerns; when I was shooting HP I de-primed cases in a Co-Ax press that sends the primers into a jar. Primers and solids recovered from casting and fluxing go into a 3 pound coffee can. Then at the end of the day I pour a cup of wet mix Plaster-of-Paris over it. When the can is full it goes the sanitary landfill.

 

[Ian]

I have entombed primers in small plastic containers in a few concrete slabs.

 

[Chris]

Well I guess I better shape up. Been kind of a slob about this, just pitch the leftovers into the garbage.

 

[Brad]

My spent primers go into a large olive jar til it is filled. They then go into my scrap brass bucket for recycling. They don't bother me as much as the dust from a tumbler. Look at the grunge that builds up on the media, some of that is lead salts which can be absorbed easily thru the human GI tract.

A wet tumbler does greatly reduce the threat from lead salts in the dust from brass cleaning.

Don't forget, elemental lead is relatively inert. It doesn't dissolve well in the human GI tract. Lead shot in waterfowl was an issue because of the gizzards and stones constantly grinding on the lead. We don't chew shot like that, or at least I sure don't.

 

[Tony]

How do you guys dispose of the fluid from your wet tumbling operations?

 

[Brad]

Mine goes down the drain. Probably not the best choice but it is what I do.

 

[Tony]

See there. I just drifted my own thread!