Possibly the best Flux??? IDK

[ulav8r]

Did my first casting about 35 years ago. Have most of a container of Marvelux left. Memory seems to be that it worked well. At that time I used a pot and dipper. Went through about 3 gallons of wheel weights, using a 214 gr. Lee 44 and a 150 gr. lee 30 mold. Have recently acquired a few more molds and some wheel weights. About a month ago I smelted about 62 pounds of WW and 24 pounds of Came lead. 2 days ago I smelted another 125 lbs of WW. On these last two smelts I used motor oil and wood shavings for flux. On the last batch I also picked up a Red Cedar limb to stir the pot. Got good clean ingots with little dross loss.

[bruce381]

I think high vs low surface tension here is backward. In my job we want LOWER surface tension so that water based cleaners will WET out on various substrates like metal.

High surface tension mean that the water based cleaners will NOT wet out effectivly on oily metal surfaces and as such they take much longer to clean the metal surface.
This is the only definition I have know about surface tension.

I would say you want a low surface tension when casting so that the lead will "wet out" and flow into all the nooks and crannies of a mold. High surface tension will cause no wetting or bad fill out.

bruce

[Rusty W]

It's a mess. Everything will be black. Seen no difference between it & sawdust. The sawdust doesn't make such a mess.

[HORNET]

Thanks, Rusty. Theory and conjecture are fine but nothing beats actual testing.

[sagacious]

I think high vs low surface tension here is backward. In my job we want LOWER surface tension so that water based cleaners will WET out on various substrates like metal.

High surface tension mean that the water based cleaners will NOT wet out effectivly on oily metal surfaces and as such they take much longer to clean the metal surface.
This is the only definition I have know about surface tension.

I would say you want a low surface tension when casting so that the lead will "wet out" and flow into all the nooks and crannies of a mold. High surface tension will cause no wetting or bad fill out.

bruce

That's a good idea, but the analogy of water (when used with a surfactant as a polar molecule) to render oily substances soluble, is not apt as compared with the non-polar, non-wetting action of lead filling a cavity. The lead just fills the cavity, and it's high density overwhelms any effect of meniscus at proper pouring temp.

"High surface tension" is a relative term. It does not mean "extreme surface tension." All it means is that the surface of the lead is... lead molecules, and not lead oxide or another lead compound. I reckon it's fairly uncontroversial that a clean lead surface hugely promotes fillout. That's what high surface tension means to casting/pouring lead. Good luck.

[Longwood]

If I remember my inorganic chemistry correctly, the reaction won't go that direction. Pb++ has a lower (barely) electrode potential than H+.

The best flux that I've found is lard or Crisco. It works about like old motor oil but it doesn't flame up or stink as much. And it leaves an oily film (glycerin?) on top that lasts a long time. I have some chicken fat in the fridge; I'll try that text time. It should work exactly the same.

I used to use old bacon grease for lube when taping holes. Stays solid till you need it, dip in the tap and as you are threading the hole, the tap warms the grease enough to smell like breakfast cooking. Pretty nice actually. Might work for a really good smelling flux.

If you guys want to play with pure carbon, look at lampblack which is nothing but smoke. No gritty particles to worry about getting in the batch.
LS

[lwknight]

I think all this fluxing business is overrated
The first geatest thing fluxing does when smelting , is to cause the alloy to let go of the junk like clips,jackets, and other particulates that would take a good bit of your alloy away with it otherwise when you skim the sufrace.

You can never actually get the fluxing agent into the melt. You might get it temporarily under the surface but it will be immediately spat right back out.

Fine particles of dust or carbon that may have gotten stirred into the alloy will float to the top , flux or no flux. The very fine particles will float up slowly and stop just under the surface. When we use a liquid hydrocarbon on the furface , it releases whats trapped underneath to be skimmed off. If you keep stirring , these fines will never surface and 50 gallons of your favorite flux will not bring them out.

When alloy is drained from a bottom pour , what comes out is no different when fluxed 50 times as what has never been fluxed. What is different is that you just get the fines out of the alloy so that they will not be stirred back into suspension.

Its like turbid water. Even the most turbid water will eventually precipitate the turbidity if you leave it set still long enough.

Once your alloy is actually clean because you let it sit still for a little while and fluxed the surface to release the contaminates trapped under the surface , the only thing left for flux to do is reducing the oxides back into their respective bases.

If you melt something with a lot of surface area like linotype letters or range scrap , you will have a lot of oxides that can be 99% reduced by stirring the pee waddly out of it while the flux is yet flaming. Only a little fine dust will remain on the surface.

I have tried the saw dust, oil , june bugs , chaws , wax , and all kinds of things and really only found that liquid reduces oxides the best and the dry saw dust and what not is less effective but , don't smell as bad or smoke as much.

Right or wrong thats what I think from a lot of years of metal melting and playing.

[Three44s]

Carnuba wax was mentioned as an added fluxing agent.

Would this liquid suffice?


http://www.aumauto.com/mo2.html

Or should it be a solid form?

Wood substances and bullet lube has been my mainstay fluxers since I divorced myself from Marvelux.

Right now, I've got a huge block of candle wax sitting around that cost zero ...... I think it would be a cheaper run than burning up more bullet lube.

I see the value in using wood with plenty of pitch for it's rosin value ..... pine knots run through a radial arm or table saw looks like it's in my future!

(Learn something new if you care to ...... everyday!)

A big welcome to XX........ you've sure stirred the pot! (pun intended!) ...... job well done!

Three 44s

[Wayne Smith]

Sagatious, others with a chemical background - since we are talking about fluxes and using wood products, what, if anything, is the consequence of using pressure treated wood sawdust? Introducing a few arsenic salts into the mix? Not enough to notice?

[lwknight]

The arsenic salts in treated lumber are toxic. AKA pesticidal.
Its hard to find arsenial wood anymore though.
They did away with the arsenic.
It seems that kids in school liked to chew on the jungle gym made from treated lumber.

[Bret4207]

That's why so much of your "treated" lumber these days is stamped "NOT FOR GROUND CONTACT". IOW, it's not really the treated lumber we had 25 years ago. It's SYP with green stain that helps a little.

[xXFREEDOMisNOTfreeXx]

(Learn something new if you care to ...... everyday!)

A big welcome to XX........ you've sure stirred the pot! (pun intended!) ...... job well done!

LOL, I have to say I have learned A LOT of info in the last couple weeks from this post. I am very grateful for all of the knowledge that has been poured into this thread. You guys have no idea how helpful this info is, and will be, to the other newbs who end up reading it. All the responses here have saved me so much time and aggravation.

I do have one more question on the subject of "fluxing" and that is....

When i flux with wax/sawdust/sticks etc, i noticed in my very first few fluxing runs that I was skimming off "chunky" looking dross. After fluxing a few more pots in the days to follow I was playing around with the smelt trying different things in which i added about a table spoon full of wax compared to only a small pea sized ball that i had used before. After adding more wax this time i noticed that the dross on the top of the pot was a "dust" like substance rather than the chunky grit before. Is this dust what i am looking for? My theory is that when i see the dust on the top it is more of a refined and tell-tale sign of a cleaner pot of lead due to me using more wax. Am I correct by saying this? All-in-all im kind of trying to figure out how much flux to use(wax)...

[lwknight]

I bet the chunky stuff is heavy. Generous fluxing will reduce most of it back to alloy and the dust left is just carbon.
I get the chunky stuff when smelting and just stir and smash the stuff while the pot is flaming from burning whatever. When it burns out most of the crud will have disappeared and have dust in its place.