September 23, 2012, 11:56 AM
I've just been using motor oil for fluxing alloys for bullet casting.

It seems to work pretty well.

Just wondering if anybody has found anything thats cheaper, or that has some magical properties I've been missing this whole time ?

If you enjoyed reading about "Fluxing" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
September 23, 2012, 12:03 PM

September 23, 2012, 12:51 PM
Bottom pour or dipper?

September 23, 2012, 12:59 PM
Sawdust works best.

September 23, 2012, 01:48 PM
I've tried everything, and sawdust works best. If you use hardwoods, it smells better, too. The only drawback is there's a lot of smoke as it's charing. You let it go until it forms dark ash, as it's the carbon that does the fluxing. Then stir your alloy. If you leave a layer of the ash on top of the alloy while it's molten, it slows down the oxidation, too.

There are a few exotic woods you want to stay away from, since they emit poisonous toxins when burned, but they're mostly from the tropics. Poison oak would also be a bad choice.............

Pine and oak work well, as well as alder and maple shavings or sawdust. If you do any woodworking at all, it's free. You can also sometimes get a bag of wood pellets for pellet stoves that's gotten wet. I've purchased a 40 pound bag for a dollar, since they can't be used for a pellet stove once the pellets have gotten wet and reverted back to coarse sawdust. The store is usually just glad to be rid of them.

Hope this helps.


September 23, 2012, 08:12 PM
Yep I cut some hard wood (oak) stair treads to size and that sawdust was great for fluxing the lead. I guess I will just cut the small ends up to make more sawdust till they are used up.:) Have you any woodworking shops nearby. I would think that fine pet shavings (bedding) would work well also.

September 23, 2012, 08:47 PM
Well, I get used motor oil for free too, so I guess its about the same price you guys pay for sawdust.

It has plenty of carbon.........

September 23, 2012, 08:50 PM
Bottom pour- not sure how that will help though - I alloy and make ingots.

I'd never do all that mixing and fluxing and BLEH in my production furnace.

September 23, 2012, 09:43 PM
Some people are afraid of sawdust in a bottom pour because of the chance of a plugged spout.
Baloney really.
I smelt in a big old cast iron pot and don't worry about a few bits of carbon stuck to the sides or bottom.
I use a stainless pot for casting and scrape the sides and bottom with an old metal spoon to be sure everything comes to the top.
That's all it takes.
Sawdust, wood chips work great as a flux, doesn't stink as bad as old oil.
I always have a lot of it around anyway.

September 25, 2012, 09:00 PM
I flux with parrafin & stir with a paint stik , make sure it`s completely dry before stirring .

I use sawdust in the smelting pot .

September 25, 2012, 09:45 PM
Sawdust, charcoal briquets (smashed into a powder with a hammer), old remnants of used up candles. They all work, but I do like the sawdust and charcoal as it leaves a layer of ash on top that prevents oxidizing of the alloy.

September 25, 2012, 10:07 PM
I have used lots of things but never motor oil! Wax, sawdust, bullet lube, powdered rosin, but the commercial product Marvelux is the best. No smoke, no mess and ten dollar's worth lasts years.

If you enjoyed reading about "Fluxing" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!