Flux and casting

Hi all, got a question about flux and casting. I've read on other forums about using candle wax as flux when melting lead but none of these forums say how much to use as in per kg of lead. Also whats the deal with using sawdust?
Thanks

I use bee's wax
One tea spoon per new lot full of scrap lead
The smoke is pretty bad so leave it to do it's thing when fluxing

Have fun, it is fun.
Bit of advice, dont think anything is 'dry' until it has been hit with a blow torch or left to dry on top of the pot.

The tiny amount of moisture in the 'grain' of the 'tool' (happened to me with a dessert spoon) is not visable but enough to cause a fright or worse when the tool is submerged into molten lead.

Long story short... hit everything with the gas torch before you use it.

Wear gloves, goggles and no synthetic clothes. Including synthetic shoes.

Save the injuries for another past time!

Candle wax will work, as will beef dripping and beeswax. There is no set ratio a blob about fingernail size is good for most, more takes too long to burn off.
The Flux is just there to bind impurities like dirt, oxide, and other contaminants floating on the surface together making them easier to remove.
To stop the smoke a match will ignite it and it will happily burn.
The advice on moisture is good, I always leave molds, ladles, and scooping spoon by the pot to heat up. One extra caution I would add if using beeswax especially in summer is the smell can attract unwanted visitors like wasps and bees.

As mentioned by @Marty Henry...you ignite the smoke.
I cast bullets for many years (.45 and .58 cal).
I used to roll up a wee 'candle' of newspaper to ignite the smoke (yes, it really does burn).
Why not let it smoke? Because that smoke contains real bad shit. You do NOT want that smoking away inside your garage/shed to leave a toxic layer in the building.
Even when casting outside...ignite that smoke. The fumes are dangerous to not only you but particularly infants, small children, and pregnant women (can damage the foetus).
Wear gloves, and a mask. You do not want lead poisoning from your hobby.
Wash yourself after the casting is finished...a shower is good as fumes will have left crap in your hair too.
For flux, I too used bees wax, but a 1/2 walnut sized lump of dripping works just fine too.
Once it's fluxed, stir the hot mixture with an old hacksaw blade. The crap and slag will stick to the saw blade, then dong the saw blade onto a handy brick, rock, whatever and all the crap falls straight off.
Give another wee stir around. If the saw blade comes out clean then you are ready to cast.
Don't forget to heat your mold in the mixture so that lead and mold are similar temperature.
You can add the odd wheel weight to the brew to make it a 'harder' lead too. Antimony, from memory, is whats in the wheel weight.
Anyway, it's easy to do, but always remember about safe practices. Don't risk your health, or your kids health.

a handful ( maybe two heaped tablespoons of sawdust ( I used to use my tea-tree(?) smoker stuff, sprinkle on the top and leave whilst pot is heating up and it is dried out. will go black from the heat and then you can carefully stir that through the molten lead whereby it does its magic and collects unwanted contaminates.
Far easier to keep the pot clean I found using a dry flux and you end up taking it all out as you begin to scoop off the dross. Once scooped off and you are happy with that your mix is clean I used to throw another couple of spoons, about 1/8th of an inch thick, on top of the clean mix as a cushion to stop any drips going in and prepping the sawdust for the next dross cleaning.
As others have said, you don't want to be pushing anything under the surface until you know it is 100% dry.

The cleanest way to Flux lead is to stir it with a wooden stick the carbon from the stick is the best flux; like sawdust without the rubbish floating
around, Bee's and Candle wax do flux but not very well and they generate too much smoke also makes a mess of your melting pot, Don't melt down
scrap lead in the pot you cast from only put cleaned lead it that.