Beeswax As Casting Flux? Borax?

[Hansj]

I took my first step into casting my own boolits today and I used beeswax as my flux (I have a good supply at hand because I am a beekeeper) but I was disappointed with the results. I was left with a black film on top of the lead and down the sides of my casting pot (RCBS 22lb Pro-Melt). I did turn out some good boolits from the pot but I am still wondering if I should use something else to flux with. I have seen the sawdust mentioned and candle wax (paraffin) as well as ATF. I am all for doing it on the cheap but if it doesn't flux really freakin well I would rather spend a few more pennies to get the lead cleaner.

I commonly use Borax as a flux for brazing or forge welding, would that work or does it require too high of a temperature to be effective?

[randyrat]

I took my first step into casting my own boolits today and I used beeswax as my flux (I have a good supply at hand because I am a beekeeper) but I was disappointed with the results. I was left with a black film on top of the lead and down the sides of my casting pot (RCBS 22lb Pro-Melt). I did turn out some good boolits from the pot but I am still wondering if I should use something else to flux with. I have seen the sawdust mentioned and candle wax (paraffin) as well as ATF. I am all for doing it on the cheap but if it doesn't flux really freakin well I would rather spend a few more pennies to get the lead cleaner.

I commonly use Borax as a flux for brazing or forge welding, would that work or does it require too high of a temperature to be effective?

I use my scrap beeswax to coat my Lee casting pot as flux, kinda rust proofs it. don't worry about the dark black stuff, it will be scraped off anyway once it burns enough.


Your talking about your casting pot. Whatever you use for flux, doesn't matter.. For sure use an oak stick to scrape the sides down, you will have less plugging and things will be cleaner. When I learned this my bottom pour pot hasn't been plugged since. Use an oak stick because, it will last longer than a soft wooden stick. Also never run it out completely, that's how you plug them up.
Borrax - I'm not sure how it works

[stubshaft]

If beeswax left a film you may be using too much of it, fluxing too often or alloy is too cold. I have used borax but too me it makes too much of a mess.

I currently use sawdust or beeswax. When I heat up the pot I'll put sawdust on top of the alloy and once it starts to char, I'll stir it and strain it off. About once every 20 - 30 minutes or if I notice alot of oxidation/crud on the melt I'll drop a piece of BW about the size of a small pea on the melt and stir for 30 seconds. Whatever remains after that time gets strained/removed with the dross.

[454PB]

I cast indoors with no ventilation, so I use Marvelux or the Frankford Arsenal equivalent for casting. For smelting, I do that with good ventilation and use anything that contains carbon. I've never tried borax, but if it's brazing flux, it would probably leave a hard, glass like crust on the surface of the melt.

[geargnasher]

I agree that if you have a black, oily coating on your pot you used too much, although the residue really won't hurt anything at all. A pea-sized blob of beeswax is enough to "flux" 20 lbs of alloy.

If your alloy is fairly clean to begin with, all you need to do when your casting pot is up to temperature is reduce the oxides that float up to the surface, especially after adding ingots. Adding any kind of wax, oil, sawdust, dry leaves, pine knots, etc. chemically reduces the oxides back into elemental metals, leaving a shiny, oxide-free surface. Just about anything that will smolder slowly on the surface will work, since the presence of carbon (soot) and carbon monoxide from poor combustion of the "flux" are responsible for the reaction that turns oxide scum back into shiny metal.

I tried Borax once, it's too messy and really isn't suitable for lead boolit casting in my opinion, and it doesn't reduce oxides at all. Borate glass is a pain to deal with, but if you want to try it yourself the instructions in Lyman cast bullet handbook #3 are good.

Really all you need are some beewax or paraffin bits (I use the ribbons that leak out of my Lyman 450) and a wooden stick for stirring and working the scum into a pile against the side of the pot, I find that "massaging" the oxide against the sides of the pot with a stick is usually good enough by itself. Use an old, long-handled tea spoon to skim out the fine, grey ash that is left from the stick.

One note on the bottom-pour furnace, try not to scrape the bottom of the pot with your wooden stick, ash will slough off the end of the stick and get trapped under the weight of the melt, since it is too fine to break the surface tension of the lead on the underside. This ash will migrate to the spout and show up in your boolits as a minor annoyance. For cleaning the bottom of the pot, use the tea spoon to scrape trash to the edges of the bottom and up the sides to the surface, like carding rust or squeegee-ing a window.

Gear

[Hansj]

Hmmm. Lots of great information. I probably did use too much beeswax then, or actually I did without a doubt. I also drained out the pot without leaving anything inside to "seal" it. I was getting some poor flow out of it towards the end of the pot so that might be the plugging taking place. How should I deal with that? The inside of the pot looks pretty crappy, not at all clean. Looks like the insides of Ted Kennedy's liver. I have plenty of oak and some other harder woods available, would Manzanita or Madrone be better? (using the old "some is good, more is better and too much is just right" mantra) and should I also use oak sawdust over pine?

[oneokie]

My best results for fluxing has been with hardwood sawdust. Put a layer about 1/4" thick on top of the melt and start casting. I can empty the pot and there is no crud stuck to the walls or metering rod.

I'm thinking the borax brazing flux would be similar to the Marvelux flux. The big drawback would be its hygroscopic properties. It will draw moisture, which can cause the tinsel fairy to visit.

[stubshaft]

No worries Hansj. It takes some trial and error to apply the written word to the realties of casting. Just call it practice.

Heat the pot up and get most of the gunk off of the sides and bottom. Let it cool and clean down to bare metal then try again.

Pine is good, usually has a higer level of rosin than oak.

[mpmarty]

sawdust, beeswax or bullet lube all work fine for me. I don't flux as much as some here recommend. Generally at the start of a casting session and then not again for an hour or so. I don't use beeswax in summer as I drew a swarm of bees with the odor once.

[Hansj]

I am thinking the borax would be good for the smelting but bad for the casting. Of course it is always absolutely essential to make sure you have dry borax. I am thinking that the glass would better suspend the junk in it and make it easier to pull it out with a the slotted spoon. Maybe not but I will let you know.

[Hansj]

mpmarty said "I don't use beeswax in summer as I drew a swarm of bees with the odor once."

Funny, not too long after we started up the melting pot a couple of the bees buzzed the melting pot (within an inch of it) for about a minute and then flew off quickly. It was noticeable to all 3 of us. After that we didn't notice any more, but the temperature did drop off a bit so they might have just gone back in the hives. Of course, we have several hives and don't really notice bees buzzing around us.

[nanuk]

so am I correct in thinking the sugars/honey residues left on beewax does no harm and can actually be beneficial, as it is carbon based?

[Hansj]

Nanuk,
When I render out my beeswax it separates out the honey pretty thoroughly because beeswax (9.3336 lbs per gallon) is quite a bit lighter than honey (12 lbs per gallon). You are right that the sugars would be high in carbon, also it seems to me that the darker the beeswax is colored the more carbon-ish stuff is in it. The lightest beeswax comes from the honeycomb cappings which is "virgin" beeswax, coming directly from the wax glands on the bees and immediately installed on the honeycomb caps (this is the wax I used) and is typically sold as "white" beeswax. The yellower/browner stuff is wax that has been in the hive longer including the brood comb which is sometimes almost black due to the amount of junk in it (the brood comb is analogous to a continuously used uterus being re-used every 21 days without the regular "purging"). Of course this is just more carbon, isn't it? Maybe I should have used some brood comb beeswax.

[dromia]

Stir with a dry stick, it works as good as anything else. No greasy smoke to deal with and depending on the wood it can smell quiet aromatic.