Do you flux in your casting pot

[wtfooptimax200]

Is it necessary to flux in your casting pot if you've fluxed very well during the smelting phase? It seems that the flux would make a mess in a bottom pour pot and possible cause problems if it made it's way down to the spout, Your opinions are appreciated.

[WHITETAIL]

No I donot.
I flux when I smelt.:cbpour:

[cutter_spc]

Yes I do. My understanding is that it helps break the surface tension so that the metals mix better and stay mixed. I flux at the start of each casting session and several time through out. Am I wrong on this?

[turbo1889]

Yes, I flux in my bottom pore casting pot. But not near as aggressively or as often as when smelting.

[Wayne Smith]

You accomplish the same thing with a thin layer of kitty litter or charcoal on top of the melt in a bottom pour pot. It stops the O2 from contacting the surface of the melt, thus no oxydation.

[Bret4207]

I believe you need too, especially if you use a cast or ferrous pot. The rust under the surface flakes off into the mix fromthe heat alone. Best to play it safe. The fluxed material should rise to the surface if you flux right.

[JonB_in_Glencoe]

I gently stirr the melt with a charred wooden stick after the alloy has melted,
be sure to scrape the sides.
I always leave a layer of dross on the top of the melt in my bottom pour pot.
I then a layer of Patmarlins CFF and I let those two do their dance.
it keeps more dross from forming,
I never drain the pot dry.
no problems so far.
Jon

[357shooter]

Sometimes I do, sometimes not. Can't tell the difference from the resulting bullets in how they look, measure, weigh and shoot.

That's with bullets in the 150-180 grain weight range. The lead has already been heavily fluxed with sawdust when originally smelted.

Added later: I have yet to have an oxidation problem either fluxing or not. Even with a hot pot, 850 - 950 degrees. My alloy is very soft, BHN 8 when possible, FYI. Hard alloy may act differently.

[zomby woof]

I flux during smelting. I use a bottom pour. I leave kitty litter on top and stir with a wooden stick every once in a while. seems to work out fine.

[snuffy]

The only time I DON'T flux my casting pot is when it's turned OFF!

Anytime it's being used it gets fluxed when it's up to temp, and when I add ingots or sprues to the pot. Contact with the molten metal with the air causes oxidation of the surface. The tin oxidizes first, NOT fluxing means your valuable tin is leaving the metal gradually as you cast. IOW your tin content,(of the boolits), gradually DEcreases as you cast if you don't flux.

Your carefully cast ingots from your smelt have a layer of lead oxide on them unless you just made them. That lead oxide needs to be re-combined with the metallic lead when you fill up your pot. The only way to do that is to flux. Fluxing reduces the lead oxide back to metallic lead. If you DON'T flux, you're skimming and throwing away valuable lead and the other two, tin and antimony.

As long as you don't disturb the surface of the melt, AND you keep the temp below 700 degrees, you shouldn't need to flux while bottom pouring. Ladle casters are constantly dipping into the melt, dross formation is constant, elevated, and needs to be fluxed back into the melt often. Using sawdust to flux, then leaving it on the surface is a good idea for the bottom pour crowd. It insulates the lead from the atmosphere, keeps the metals mixed.

[res45]

I like a heaping spoonful of hardwood sawdust in my bottom pour pot,I just leave the char on top and remove it before adding more lead.

[GP100man]

I flux anytime I add anything to the pot & leave the dross on top to form a barrier from 02 .

[timkelley]

Two or three times during a casting session (two hours) to keep the tin in the melt. Seems to work for me since I most always get good pours after I get a mold figured out.

[Hardcast416taylor]

I do a good fluxing when I smelt, I flux again when I mix an alloy and I flux when I get my bottom pour up to temp then I leave the dross on the surface with some sawdust. I guess I`m a clean freak when it comes to what is going down my gun barrels that I paid good money for!Robert

[plainsman456]

I put some saw dust on top of the pot when casting boolits.It goes on when taking a break as well.By the time you get back to casting it has turned to charcoal and and you are good to go.
It helps keep the tin where you want it.

[ku4hx]

I have a Lyman "20 pound" furnace and I flux once when the melt is up to temp and then once again when it's about 1/2 cast. I use a match head size bit of Ney Vita-N-Flux Fluxing Compound I was given 30+ years ago by the owner of a print shop that was going out of business. I bought his entire inventory of Linotype alloy.

I flux heavily when smelting using various materials, but never trust that to get 100% of the contaminates.

[geargnasher]

FLUX or REDUCE?

I do most of the fluxing, or cleaning/removing of impurities through chemical means, when smelting. For that I use sawdust and stir with a stick. Then I skim and do it again, two more times. Sawdust also provides enough sacrificial carbon to reduce the lead, antimony, and tin oxides back to their elemental state while I'm fluxing, so both operations take place at once when using sawdust.

Since the ingots oxidize, and the surface of our boolit alloy oxidizes every time it is exposed to oxygen, it's necessary to "reduce" these oxides in the casting pot. I use more sawdust for this as well, and just leave a layer of it on top of the pot after stirring with a stick, this makes a great oxygen barrier when using a bottom-pour. If you ladle, using wax or old boolit lube instead of sawdust to reduce the oxides when they get thick minimizes the ash. Light the smoke and stir with a spoon, scrape out the scum layer and resume casting.

Gear

[DLCTEX]

I stir well with a wooden stick when the alloy has melted and skim off the dross before casting. Any oxides float on top and I don't completely empty the pot before adding more alloy, then stir again with the stick and skim.

[ColColt]

Once everything gets to about 650 degrees, I put in a big tablespoon of sawdust and let it burn till brown. Then I stir real good and skim off the junk on top, add more sawdust to keep the mix from oxidizing and commence to cast. During the session I'll usually stir, flux a couple two or three more times. I feel it helps keep things "homogenized" and dirt out of the mold.

[mpmarty]

I always add CFF on my bottom pour twenty pounder and stir with a wooden dowel or paint stick. I leave the ash on top to act as a barrier and repeat when I toss in more ingots.

[BOOM BOOM]

hi,
I usually flux 3 times a pot.:Fire::Fire:

[Cherokee]

I don't flux, I leave the dross on top to reduce the air exposure.