Low cost choices for fluxing?

[huntrick64]

I have been using sawdust for years and recently stumbled on to the "perfect" sawdust for fluxing. I build selfbows from Osage Orange staves. Sometimes I use a jointer to flatten the back of the stave so i can glue bamboo on the back. The little chips of osage orange that come out of my jointer are perfect! The chips are about 1/64th inch thick and about 1/8 inch in diameter. There are not many woods more dense than osage (sometimes it doesn't even float in water). It is very pleasant smelling when it chars on top of the lead. I flux 2 or 3 times removing the impurities each time. The fourth time I cover the top of the lead and let it set there and smolder while casting. In one session of working osage I ended up with a wal-mart sack full of chips. Will last me and my casting buddy a while.

[geargnasher]

We call it Bodark here, and in central Texas it's commonly used for fence posts, a duty it can perform for centuries if the top is cut properly and the bark remove. Sacrilege, I know. It's a beautiful wood. Just about any wood makes good flux, just watch out for walnut and Western (aromatic) Cedar, some of the chemicals in it are harmful to people when it's burned.

Gear

[D Crockett]

let's see things I have used for flux candle wax , bees wax , tolit rings wax , a paint stir stick , a hand full of dry leafs off the groung , used moter oil , chinese chop stick , saw dust , sap from a pine tree , a mixture of candle wax and the stuff you have left over when cleaning bees wax , bullet lube , and Marvelx which I do not recomend becouse of the steem explosions it can couse if you do not know how to use it right D Crockett

[Longwood]

let's see things I have used for flux candle wax , bees wax , tolit rings wax , a paint stir stick , a hand full of dry leafs off the groung , used moter oil , chinese chop stick , saw dust , sap from a pine tree , a mixture of candle wax and the stuff you have left over when cleaning bees wax , bullet lube , and Marvelx which I do not recomend becouse of the steem explosions it can couse if you do not know how to use it right D Crockett

No "Bar" lard?

[Ron r]

Should be lub left on some of them
If not I use the boolits that hit the floor
After lubbing work good for me.

[km101]

Is anyone stil out there? Will any type of sawdust work? I mean from any type of wood. Any wood that works better or worse? I am new to all this, and this is the first time that I have heard of using sawdust. What should I look for to tell if it's working? This is very interesting and I want to try it, but I need a little more info on the process to feel comfortable.

KM101

NRA Life Member

[just.don]

high rosin content pine seems to be among the popular choices

[H.Callahan]

high rosin content pine seems to be among the popular choices

+1 Pine seems to be the acknowledged standard, although other woods can work as well. I think because pine is easily obtainable and there is nothing that works any better, it is what most people use/recommend when fluxing with sawdust.

[Wayne Smith]

The issue is not the wood, it is the creation of carbon. Any wood or wood product will work. Avoid pressure treated wood. It is the carbon that is the reducing agent, I understand. Byproducts of smell are personal choices.

[John in WI]

on this last back of range scrap, I tried something new. The extremely hot and dry summer here has my pine trees literally leaking sap. Huge balls of straight pine sap coming out through the bark.

It seemed to work like a charm--just like using saw dust without the dust. The resin burned away without a trace.

A warning about straight pine pitch--be careful with it. It burns with really frightening heat (like Greek Fire!). So start small, and get it burning before you add any more. Anyway, I think I'm going to collect as much as I can (without actually damaging the tree) and use it.

[geargnasher]

on this last back of range scrap, I tried something new. The extremely hot and dry summer here has my pine trees literally leaking sap. Huge balls of straight pine sap coming out through the bark.

It seemed to work like a charm--just like using saw dust without the dust. The resin burned away without a trace.

A warning about straight pine pitch--be careful with it. It burns with really frightening heat (like Greek Fire!). So start small, and get it burning before you add any more. Anyway, I think I'm going to collect as much as I can (without actually damaging the tree) and use it.

I'm going to keep saying it.

Hydrocarbons burn. Combustion is a sort of reduction/oxidation reaction. When combustion occurs in the presence of metal oxides, they give up their oxygen to the process and return to their elemental state. The oxygen and reduced carbon becomes CO2. This redox reaction reduces the oxides and oxidizes the carbon.

THIS IS NOT FLUXING, IT'S REDUCING.

Fluxing is the process of removing the impurities that impede the casting qualities of the alloy, while preserving the things we want, like arsenic, antimony, and tin. Introducing carbohydrates to the melt is what isolates and absorbs these impurities so they can be skimmed away. Borate fluxes and wood pulp are two of the very best things to use for this purpose, and the borates come with so many drawbacks that sawdust, leaves, wood chips, shavings, or simply stirring with a pine stick for long enough to char a good bit of it away is the "best" thing I've tried.

We need to both reduce and flux our scrap metals. Clean foundry metal probably only needs to have the oxide scum reduced from time to time in the casting pot, nothing more. But wheel weights and other contaminated scrap with all sorts of trace impurities that don't help the casting process at all in it works better with a good cleaning. Rosins, grease, wax, oil, etc. works fine for reducing oxides, but doesn't do a thing for the aluminum, calcium, iron, zinc, etc. that's mucking up the works. That's why you need sawdust for dirty scrap.

Gear

[Boyscout]

Following a similar thread, I tried a dried stick to stir a pot of wheel weight lead I was cleaning up for ingots. After skimming the dross created from using the stick, I followed up with some stick Alox to flux; I got very little impurities on the second flux. Has anyone tried pine needles?

[Boyscout]

Following a similar thread, I tried a dried stick to stir a pot of wheel weight lead I was cleaning up for ingots. After skimming the dross created from using the stick, I followed up with some stick Alox to flux; I got very little impurities on the second flux. Has anyone tried pine needles?

"Everyone is entitled to an educated opinion>"

[just.don]

"THIS IS NOT FLUXING, IT'S REDUCING."
Bless your heart Sir. Your patience is admirable!

[Longwood]

Following a similar thread, I tried a dried stick to stir a pot of wheel weight lead I was cleaning up for ingots. After skimming the dross created from using the stick, I followed up with some stick Alox to flux; I got very little impurities on the second flux. Has anyone tried pine needles?

A member brought them up about a year ago and said they worked fine.
They sure won't hurt anything, plus they should smell good.
I got a small tub of dried (practically Amber), pitch balls from some huge Sugar-Pine trees, a few days ago but have not had a chance to try it yet.
Stirring with a stick, also requires some scraping with a spoon etc. to clean the sides and bottoms of the pot,,, because the sticks leave lots of stuff in the pot. Not important when smelting but very much so if casting with a bottom spout pot.

[geargnasher]

A pine stick is like a Magic Eraser for junk stuck to spoons, the sides of the pot, or anything covered in hot oxide scum. If you use a pine stick to "police" the scum in the pot from time to time this is all you need.

As the alloy level falls in a pot there's always silvery scum hanging in big patches along the sides. Take your stick and wipe it off, a spoon won't get it clean, but a stick will. Police all the scum into a pile on the melt's surface near an edge, and work it against the side of the pot with the stick. Shortly, all the good metal will be extracted from the pile and all you'll be left with is a small pinch of grey ash, easily skimmed out with the tip of a spoon. Use the stick to get the cling-ons of the valve pintle on your bottom-pour (when everything's hot, of course), and also off the thermometer probe if you use one.

One caveat, though, DO NOT scrape the bottom of a bottom-pour pot with the wood stick. This is a certain way to get ash trash trapped under the melt, and that trash will migrate to the spout and come out as ugly little pits called "inclusions" in your boolits. Some of these you can see, and some are inside the boolit where you can't. Use a spoon to scrape the bottom, NEVER a stick, unless you're using a ladle-casting pot where the junk on the bottom is of no consequence.

I always have better luck doing my heavy fluxing and cleaning of alloy when I "smelt" the scrap rather than when casting. That way I only have to use a stick and maybe some rosin or some kind of wax to keep the oxides reduced in my casting pot. The oxides are constantly recurring, but once you get the impurities out, they're out. I typically double-flux and ladle the alloy through the charring layer when smelting to expose as much of the metal to the sawdust as possible, sort of like water through coffee grounds. I've noticed that the ash I skim the second time is much less clumpy and is much lighter in weight than the initial flux, this is proof enough to me that bad stuff is being absorbed by the sawdust and removed. The further proof is my experience with casting. Plain old wheel weights with a pinch of tin added and only treated with reducing agents doesn't cast nearly as well as a thoroughly fluxed alloy does. Try it for yourselves sometime and see.

But remember, if you're using grease/wax/oil/rosin or such, you are NOT fluxing or cleaning the melt, only reverting the oxides.

Gear

[Longwood]

Take your stick and wipe it off, a spoon won't get it clean, but a stick will.

Gear

Try a better shaped spoon.

[Boyscout]

I have begun to process my wheel weights in a casting pot since my 10 lb. Lee bottom pour is a no go for smelting. I have been trying to learn how to achieve a desired BHN on the first try. This thread has been really helpful and I know I am on the right track. I had been casting for handgun and accuracy was not as much of an issue at the range I have been shooting. However, I have started to shoot more CB through my rifles and need more consistancy. My last attempt to reach 19 BHN by alloying WW, 70/30 and tin got me to 20.1 BHN. My math may have been a little off but I was happy to come so close. It was a lot easier knowing my starting points. I cast a few test bullits each time I smelt to test for hardness.

[Moonie]

I have begun to process my wheel weights in a casting pot since my 10 lb. Lee bottom pour is a no go for smelting. I have been trying to learn how to achieve a desired BHN on the first try. This thread has been really helpful and I know I am on the right track. I had been casting for handgun and accuracy was not as much of an issue at the range I have been shooting. However, I have started to shoot more CB through my rifles and need more consistancy. My last attempt to reach 19 BHN by alloying WW, 70/30 and tin got me to 20.1 BHN. My math may have been a little off but I was happy to come so close. It was a lot easier knowing my starting points. I cast a few test bullits each time I smelt to test for hardness.

Am I reading this correctly that you are adding 30% tin to your WW alloy?

[geargnasher]

I got that too.

Gear