Need flux recomendation

[roverboy]

I was wondering what flux everybody is using. I've heard of using a lot of things. I heard of using candle wax, and some other stuff. Theres a product that Brownells sells called Marvelux. Any help or suggestions is appreciated.

[454PB]

I've used Marvelux for many years, because I cast indoors with no ventilation. It works well, but is hygroscopic and any of the tools used must be preheated to prevent the potentially explosive effects of introducing moisture into molten lead. This is clearly explained on the label.

However, I do my smelting outdoors, and I then use about anything that contains carbon as a fluxing agent......from used motor oil to flakes of Ivory soap.

[waksupi]

Stirring with a stick is about the best.

[plainsman456]

I have been reading about fluxing and have used old bullet lube.
When I saw how much it was now I looked for something cheaper.I found some paraffin at the store and used it when smelting some ww.
I just happened to get my chain saw back from the show and tried it out on some oak I had lying around.
After putting up with the smoke of the paraffin for a couple of hours I remembered the shavings from the saw cutting I did.
Not only did it seem to work better at keeping the tin-lead mixed it smelled much better to boot.

[Charlie Two Tracks]

Sawdust. Regular old sawdust. I live very near to a lumber yard.

[geargnasher]

Most of the time when we say "flux" in the context of boolit alloys we mean "reduce oxides", as in add something that will cause a reduction/oxidation reaction at the melt's surface and chemically render the dull, scummy layer of dross on top of the molten lead back into elemental lead, tin, and antimony (whatever is present in your alloy).

Different ways to do this, but the priciple is to introduce carbon AND carbon monoxide to the oxidized metals so they can exhange oxygen and make carbon dioxide gas. The short version is that most of the time you want to put something on your melt that will smolder or burn yellow if you light the smoke it gives off, yellow flame has lots of carbon monoxide in it due to the inefficient burn down in a lead pot where oxygen is scarce. CO and C will suck the O2 away from the metal oxides, leaving pure metal and giving off CO2.

How to do this? Introduce hydrocarbons. Like a wooden stick, sawdust, PatMarlin's Califoria Flake Flux, shredded newsprint, oily pine knots, boolit lube of any kind, or my new favorite: Juniper tree sap!

Marvellux and Borate compounds work differently, they are simply a means of sealing the melt's surface from oxygen to keep it from oxidizing in the first place. You can accomplish the same thing with Kitty Litter or a layer of sawdust in most cases, unless casting at very high temperatures (over 750 degrees in my book) for certain things like pure or near pure lead muzzleloader projectiles where high heat is needed for good fillout.

Most of the time, though, just toss in a couple of lubed boolits, stir the whole melt really well with a stick, light the smoke, and corral and skim the ash with a spoon, if you don't overheat your melt you only need to do that once each time you add lead, the slight oxide layer that does form will be fairly stable for an hour or more, the key is don't overheat your melt, because heat accelerates oxide formation drastically.

Gear

[peerlesscowboy]

I just use a bit of bullet lube.

[HammerMTB]

Most of the time when we say "flux" in the context of boolit alloys we mean "reduce oxides", as in add something that will cause a reduction/oxidation reaction at the melt's surface and chemically render the dull, scummy layer of dross on top of the molten lead back into elemental lead, tin, and antimony (whatever is present in your alloy).

Different ways to do this, but the priciple is to introduce carbon AND carbon monoxide to the oxidized metals so they can exhange oxygen and make carbon dioxide gas. The short version is that most of the time you want to put something on your melt that will smolder or burn yellow if you light the smoke it gives off, yellow flame has lots of carbon monoxide in it due to the inefficient burn down in a lead pot where oxygen is scarce. CO and C will suck the O2 away from the metal oxides, leaving pure metal and giving off CO2.

How to do this? Introduce hydrocarbons. Like a wooden stick, sawdust, PatMarlin's Califoria Flake Flux, shredded newsprint, oily pine knots, boolit lube of any kind, or my new favorite: Juniper tree sap!

Marvellux and Borate compounds work differently, they are simply a means of sealing the melt's surface from oxygen to keep it from oxidizing in the first place. You can accomplish the same thing with Kitty Litter or a layer of sawdust in most cases, unless casting at very high temperatures (over 750 degrees in my book) for certain things like pure or near pure lead muzzleloader projectiles where high heat is needed for good fillout.

Most of the time, though, just toss in a couple of lubed boolits, stir the whole melt really well with a stick, light the smoke, and corral and skim the ash with a spoon, if you don't overheat your melt you only need to do that once each time you add lead, the slight oxide layer that does form will be fairly stable for an hour or more, the key is don't overheat your melt, because heat accelerates oxide formation drastically.

Gear

What he said ^^^^^^
I use sawdust cause I get lots of it free. A wood stick to stir once it is burned black, and it keeps well. Sometimes I put some more sawdust on top and leave it so the melt won't oxidize as fast, but not always.
I've used Marvelux. I don't like it cause I have to remember to heat my utensil for stirring, and once I forgot and got the famous "tinsel-fairy" visit. I don't care for that at all. :shock:

[Jack Stanley]

I used a can of Marvelux but really didn't like it even though I was working inside . It seemed to build up a thick layer on the stirring tools more that working on the melt .

Bullet lube works as does a bag of NEI flux that I bought years ago . For those of you that might know , is this stuff the same as Pat Marlins flake flux ?

I've tried the chain saw chips as well , I cut up an apple tree and stirred with a pine limb . Thinking about adding spider webs and bat wing next time ...... :razz:

Jack

[prs]

If you wish to have an excellent flux with low smoke, consider granulated charcoal such as used in water filters and such. I cast in a well vented shop and don't mind the smole from either my scrap lubed boolits or the hardwood stir stick I cut.

prs

[stubshaft]

MANY years ago when I was a kid we went on a field trip to the local newspaper. At that time they were still using Lino to pour the plates to print. The guy in charge said that to flux the lead they threw in two Irish potatoes. Funny how I never forgot that...

[bbqncigars]

Untreated cleaning media (walnut or cob) works too. I just tried it today, 'cause the apple wood sawdust is reserved for smoking meats or cheese.


Wayne

[geargnasher]

I tried the activated carbon a while back when someone started a thread asking about it. I used some scabbed from an aquarium filter, and it didn't work well at all, just sat there. Same result with crushed charcoal pulled out of cold fireplace ashes. Cooking charcoal works so-so. This was when I called a friend of mine who's a graduate chemist and she told me about how lead oxide is reduced as a final stage in the smelting of Galena, since CO is far more reactive than C. Even, even "activated" carbon doesn't work much better because all that means is it's porous like lava rock and has a huge surface area. I always thought it was silly that people "lit off" their boolit lube flux when it started smoking, but lighting it helps produce carbon monoxide. This sort of reduction works for many non-ferrous metals, since their oxides are more reactive than iron and steel.

Someone told me that walnut gives off a poisonous gas when burned, but I can't verify that. Anybody know for sure? Maybe it was the walnut sawdust I was thinking of. I use Western Cedar shavings in the Summer when casting purely to keep the mosquitoes away, it really works! But if you're allergic to the chemical that repels insects the smoke can mess you up bigtime.

Gear

[Bret4207]

I've tried about everything. For me a simple stick is best. Not only am I introducing carbon, With a stick you can stir and scrape the pot. Since going to this method and switching to a stainless pot my dross had dropped by half at least.

[btroj]

a stick works well. I usually throw a bit of sawdust on the melt and stir away with a spoon. Sure gets the stuff on top of the melt to mix back in.

Gear pretty well hit it on the head though- you need something that burns.

[1Shirt]

I use a paint stur stick which is free at most paint stores. Like it because is has nice smooth sides to scrape the inside edges, and it chars nicely.
1Shirt!:coffee: