Fluxing....Smoke.

[Sax.45]

Hello all. I built a enclosure for casting in my basement with a exhaust fan vented outside. When fluxing if I use to much sawdust it overwhelms the exhaust fan a bit. Is there any danger from that smoke? My understanding is that lead has to be very hot, over 1000 degrees to give of harmful vapors. Am I correct in that assumption?

Thanks. :veryconfu

Sax.45.

[cbrick]

At normal casting temps the lead isn't the danger, the question is what type of sawdust are you using? Plywoods have a lot of glue that can be toxic and also cedar wood shouldn't be used.

Either don't use too much OR simply add it slower so it doesn't smoke all at once.

Rick

[Wayne Smith]

Yes, you are. Look up the specific gravity of lead, then the vapor temperature. You will be much comforted if you know what the numbers mean.

[Jim Flinchbaugh]

right about the lead part, dunno if you want smoke in the house though.
I light mine on fire- most of the smoke burns off.
Once it starts to smoke, I use a BBQ lighter to light it off

[Sax.45]

cbrick I am using pine. I try to just add a little at a time but sometimes I get carried away. I have a long lighter and will just ignite it. I was just wondering if it was dangerous. I mite just wear a resperator.

[mold maker]

No danger from the lead, but the smoke can carry particles of lead oxide with it.
That is where the dust around the area comes from.
Your concerns are founded, but easily avoided.
Also not mentioned is, not using saw dust from treated lumber. It's toxic.

[gray wolf]

Did we forget the carbon monoxide from the wood smoke ? I fought a fire one time and after we got it out, I was part of the team that looked for a rekindle in the basement, no flames and no visible smoke, I spent three days in the Hospital from residual Carbon monoxide poisoning,
my levels were high and I never saw the smoke, Had a Scott pack on while fighting the fire.
If you smell the smoke it's getting into your lungs.
Just sayin

[geargnasher]

No danger from the lead, but the smoke can carry particles of lead oxide with it.
That is where the dust around the area comes from.
Your concerns are founded, but easily avoided.
Also not mentioned is, not using saw dust from treated lumber. It's toxic.

Yes, particulate lead/lead oxide can be carried out with the soot from the smoke, as confirmed by a lead-indicating wipe used on the flue of my indoor casting vent after the very first time I cast with it and fluxed with sawdust. I would say that fluxing smoke IS a lead contamination hazard if you breathe the smoke. Lighting it should help keep it from being lifted out of the pot. That pine sawdust can generate quite a column of flame, I'm glad I made sure that my casting hood and ducting (with in-line fan 20 feet away) was capable of withstanding a pretty good fire for at least a couple of minutes.

Gear

[Westwindmike]

and also cedar wood shouldn't be used.


Rick

Can you tell me what the deal is with cedar? I've been using pencil shavings to flux with.

[geargnasher]

Here's a link telling about the several different chemicals that different cedars, Western Cedar (not a true cedar), pine etc. contain which are all very powerful respiratory irritants and carcinogens. Not trying to scare anyone off, but those using wood shavings for flux (like me) should be aware of why ventilation is doubly important when doing this:

http://www.ratfanclub.org/pine&cdr.html

Since we keep pet rats, we learned that cedar shavings is actually very harmful to them when used as a bedding material, therefore we use dust-free corncob bedding.

Gear

[geargnasher]

There are two threads going on right now here next to each other, I keep forgetting which one I'm posting in, I mentioned the hazards of fluxing with aromatic woods on the other thread, sorry if anyone missed it here, but Rick covered for me as usual :drinks:

Gear

[noylj]

I still use old bullet lube or paraffin wax. Never cared for wood. Too old to want to change, since I see no reason. Always light in on fire, myself.
Shouldn't need too much at one time--maybe problem is too much sawdust? A little pinch will do you...

[prs]

I prefer bees wax, but if you like saw dust except for the smoke and such, then try oat meal. We don,t use all that much, low smoke, rather pleasant odor.

prs

[Sax.45]

Thanks guys. The lead particulate/lead oxide was my main worry. Should I wear a proper respirator? Or is lighting the smoke enough, or both..

Sax.45

[cbrick]

Thanks guys. The lead particulate/lead oxide was my main worry. Should I wear a proper respirator? Or is lighting the smoke enough, or both.. Sax.45

As always mentioned in these threads and for a reason . . . Very good ventilation is critical if for no other reason than common sense. Lighting it on fire is fine if that's what ya want to do but it does not substitute for "good" ventilation. Vent all possible smoke or fumes to the outside. If you cannot get really good ventilation in your casting room for whatever reason then flux outside & return the fluxed pot to your casting area to cast. As was already mentioned, lead at normal casting temps will not fume and your not breathing lead simply because it's molten. That's not the case with fluxing smoke.

Rick

[cbrick]

Can you tell me what the deal is with cedar? I've been using pencil shavings to flux with.

If your ventilation system is sufficient my personal opinion is that it would be fine to use cedar but bear in mind that some are much more sensitive to this than others. In my casting room I have big time overkill ventilation, when I add sawdust and let it smoke I cannot detect the smell even slightly. Outside the door it smells like being next to a smokey campfire but inside there's not a hint. Once the sawdust is turned to carbon I'll turn down the ventilation because it's impossible to either heat or cool the room with it on high.

Rick

[geargnasher]

I still use old bullet lube or paraffin wax. Never cared for wood. Too old to want to change, since I see no reason. Always light in on fire, myself.
Shouldn't need too much at one time--maybe problem is too much sawdust? A little pinch will do you...


I prefer bees wax, but if you like saw dust except for the smoke and such, then try oat meal. We don,t use all that much, low smoke, rather pleasant odor.

prs

Grease/wax/oil doesn't FLUX the melt, although flammable hydrocarbons in any form act as a sacrificial reducant. Exposure of the alloy to carbohydrates is what FLUXES, or removes the impurities that impede the flow of the metal. Oatmeal works fine.

Gear

[Sax.45]

cbrick. What you said about proper ventilation is correct. I think I'm going to get a stronger exhaust fan. Better safe than sorry. I built my unit at 2 1/2 feet wide x 3 feet high with a hood on top and vented thru cellar window. and like you said i'll flux with smaller amounts of the pine sawdust and light the smoke. I should of got a stronger exhaust fan the first time around. :cry:

Sax.45

[gunoil]

get a bigger fan.

http://i1113.photobucket.com/albums/k511/putt2012/1B875A2E-B857-4D14-9A52-2BF3D1DDFC63-448-0000002E26F16396.mp4

[olafhardt]

I like a spoon full of sugar or chicken feed& stir with a wood stick. You could use oat meal,grits,corn meal, cream of wheat, fish scales, grasshoppers, hair clippings, cat food, cat manure(dried well) mice,etc. Oder may be a problem and living things may need to be assainated and desicated. I'm not joking,just pointing out that lots of things will work.

[atr]

my first choice is bees wax, followed by paraffin (old candles), then pieces of old lub, and lastly sawdust.

[Sax.45]

:shock:
I like a spoon full of sugar or chicken feed& stir with a wood stick. You could use oat meal,grits,corn meal, cream of wheat, fish scales, grasshoppers, hair clippings, cat food, cat manure(dried well) mice,etc. Oder may be a problem and living things may need to be assainated and desicated. I'm not joking,just pointing out that lots of things will work.

olafhardt, Yer killing me...:shock: I know you can use a lot of things for fluxing. But my wife drew the line at cat manure and mice. [smilie=s:

[geargnasher]

my first choice is bees wax, followed by paraffin (old candles), then pieces of old lub, and lastly sawdust.

See post 17. Beeswax and paraffin don't qualify as flux. Sawdust does.

Gear

[ShooterOnTheLine]

For a newbie this is great information....

[geargnasher]

For a newbie this is great information....

This is exactly why I keep harping on the fluxing vs. reducing oxides thing when people say they "flux" with grease/wax/oil. Threads here tend to get 5-10 times the views as they do responses, and keeping the facts straight as much as possible is very important to me. One bit of misinformation can frustrate dozens of people for a long time. I know, I've been that guy more than once. I've also done a bit of testing with fluxes and sacrificial reducants and it does matter what you do to your melt, especially if you source your boolit metal from dirty scrap.

You can put beeswax in your alloy until the cows come home, but it won't take out that pesky aluminum junk etc. from your dirty old wheel weight scrap, and you may have noticeable casting malfunctions sometimes that can drive you nuts if you don't know the chemistry behind what's going on, and how to fix it. I know all about pulling my hair out, adding bunches of tin, and smoking up the place with piles of paraffin trying to clean a melt before Glen Fryxell (a Ph, D. chemist, btw) wrote his article on fluxing/reducing. It takes a true flux to clean the melt of the particulars we boolit casters consider impurities (without removing all the tin and antimony too), and grease/wax/oil doesn't do it.

Gear

[cbrick]

Gear, I saw post #21 Seems some folks just don't care, sometimes I think some folks just plain and simple don't want to learn, they would have to admit there is a better way other than what they've been doing.


cat manure (dried well) mice

The kitty doo doo is out for sure but the mice work well as long as ya boil'em first to get rid of the fur. The fur stinks pretty bad when burning, almost as bad as the kitties offerings. :shock:

Rick

[Sax.45]

Thanks guys, Sawdust I have, Stronger exhaust fan I will get...