I bought some rotometals super hard

[Thomas918]

I bought 5lbs of rotometals super hard. It's 30% antimony. I was melting it down into 40lbs of soft lead and was having a hard time getting it to melt down. I put some wax in there and fluxed it. This seemed to melt down everything and I was wondering if I was removing antimony with the flux or did the wax turn the top layer into meltable antimony again?

[45DUDE]

If you have a known mold that drops a boolit at known weight you should be able to tell if hard if it drops lighter. I add things to make mine harder and lighter. I like my 148 wad cutters to weigh about 146 and I have made them weigh 142 grain. I fill my pot when through and check the weight of a known mold before I shut it down. When the pot is cooling if it develops a sink hole I will add something to smooth it more for a better looking boolit and drops a tad larger. Works for me anyway. I have a book to go by but sometimes run out of what I need. Kind of like my wife makes soup. <I am not the expert on this but get by better than most.>

[BNE]

Short answer:
Assuming you had a real melt, not a clumpy mess, then NO, you did not “flux away” the Antimony.

[Gatorhunter1313]

I have about 10 of their 5lb bars I have melted down into 1lb bars. I keep them on hand to raise the hardness of my pot if needed. I have never had a problem getting them to melt down. I stir them a lot and then cast a bullet in a mold I stuck in a mill and created a flat side. Then I don’t have to file the side to stick it in my Lee hardness tester. Works great

[405grain]

I use superhard as one of the ingredients in my casting alloy. I blend it with lead, lead free solder, and ingots cast from "BB" bird shot. This gives me an alloy of lead, antimony, tin, and traces of both copper and arsenic. First I melt the lead, and then the superhard goes in. Yes, it takes a little longer for the superhard to liquefy than it does pure lead. This is normal. fluxing won't hurt anything, and the antimony stays in solution. By contrast, when I add the tin it liquefies almost immediately, and there's a visible change in the fluidity of the alloy. If you're making a casting alloy from just lead and antimony, it can be vastly improved by adding some tin. Both the flow and the mold fill out will be better with some tin in the mix.

[Dusty Bannister]

You were probably not providing sufficient heat to make the super hard alloy fully liquid.

From the LASC site:
Alloy Maintenance: It’s not quite as simple as turning on the electric pot and pouring. A basic knowledge of caring for your alloy is required and there are a few tips that once understood makes this fairly simple. If these rules are violated the percentages of metals and quality of the alloy in your pot may not be what you thought it is.

[12]One of the most critical yet least understood casting factors is temperature. When a bullet caster refers to the melting temperature of the alloy, what he means is the solidus or the temperature at which the alloy begins to melt. More important is the liquidus temperature of the alloy, the point at which the alloy is completely molten. An alloy may appear to be completely melted in the pot when in actuality it is not, since crystal formations of some of the important constituents of the alloy, such as tin and lead or lead and antimony, still exist. What this means for the bullet caster is do not flux or add alloy (sprues, rejects or new ingots) to the pot until the alloy has reached the liquidus temperature. After adding alloy to the pot wait for the liquidus temperature to be reached before fluxing. Every time metal is added to the pot the alloy should be well fluxed. Once the liquidus temperature is reached stir the melt before fluxing to assure even heat throughout the melt. Add alloy to the pot slowly to aid in keeping the melt as close to the liquidus temperature as possible.

[Thomas918]

Thanks for the replies. I was melting this over a large propane burner so I know I can really get the temp up high. I had the flame up high. Thankfully when I waxed it everything melted up. I poured the new alloy into a muffin mold for some 2 pounds ingots to use in my lee 20. I was hardening up my whole supply of soft lead 60lbs at a time

[kevin c]

If everything melted after adding just wax, then you only removed its ash when you skimmed the melt. Same, I think, if you used a true flux like borax, which I understand absorbs mineral contaminants into the glass, leaving the metals. Both, I think, reduce metal oxides, though I don’t recall ever getting a really grotty bar of any alloy from RotoMetals, so it’s hard for me to think oxides account for all of what you had trouble with.

All good, though: you got your alloy hardened up by the amount of Sb you wanted to add.

[243winxb]

Stir pot while flexing .Like it's soup.