Lead Slag

[michael word]

I have just recently started casting my own bullets and when I melt the lead, using WW, I can not seam to get rid of a red and yellow powder like substance that builds up on the ladle and pot. It seams to become worse the hotter the lead is and will not go away no matter how many times I flux. What is causing this and how do I stop this?

[fourarmed]

What are you using for flux. Marvelux?

[michael word]

I use pariffan to flux.

[Woodwrkr]

Lead oxidizes especially when it's in the molten state. Is this just the oxidation on the top surface of the molten lead?

[454PB]

Welcome to the forum, michael.

Molten lead is constantly oxidizing and reforming dross on the surface. If you flux and then remove the dross (oxides) it immediately begins to reform. Keeping the temperature down helps minimize this, but it can not be avoided. Normally the dross is a grey color, and if I'm casting with a bottom draw pot, I leave the dross on the surface to form an oxygen barrier. If you dipper cast, it gets in the way and has to be removed.

I've never seen red dross, and yellow is usually caused by some kind of sulphur contamination. As long as your boolits are casting well, I wouldn't worry too much.

[MeestaSparkle]

Lead Oxide is read and yellow. This doesn't come from experience but from chemistry class, though. I've never had my lead oxidize into that, I would wonder if you have it too hot, or some other contamination is encouraging oxidation. How hot are you running it? Is this consistent from batch to batch of wheel weights?

[michael word]

This happens on every batch of WW that I do and at lower temperatures the red and yellow substances form a heavy coating on the dipper. I have been trying to cast hollow base bullets and have been slowly increasing the thermostat on the furnace, trying to get the mold to fill completely, and I do not have a thermometer yet to see what the actual temperature is.

[fourarmed]

I usually see this most when using Marvelux, but it happens with all fluxes. It is a material that is known technically as "crud." Additional fluxing may keep it off your dipper or not, but it will build up on the walls of the pot. Best way to get rid of it is to run the pot empty once in a while, and knock it off with sandpaper and steel wool.

[Trapshooter]

I've been able go get rid of the dross from smelting by leaving some lead in with it, and taking it back to the recycle yard I bought the wheel weights from, and selling it for lead scrap. You don't get much for it, but it is much better than tossing it into the garbage.

Trapshooter

[OLPDon]

I don't use a dipper any more (bottom pour now) but when I did I found that the dipper brought in most of my problems. To eliminate that I took a elect wire brush to it cleaned it up the dipper and brushed to a shinny apperance and that cleared up the my problem of contamination.
Just to note I only stoped dipping to increase speed and to make my casting a little easer and increase productivaty. I feel every time you disturb the surface of the alloy you add contaminates. I also put clay kitty litter on surface of mix to keep oxidation down.

When ever I make a change to something in casting I go the way of: make sure it can be reversed and cause no further harm to the Item.

If I were still dipping I would, after cleaning the dipper I would spray the outside portion of the dipper with Dropout (moly spray) that would I think keep the dipper nice and clean.

Don


Don

[454PB]

If you have a digital camera, take some pictures of this colored dross. In 37 years of casting, I've never seen red dross.

[goon]

I am also getting red dross while smelting. I have very little experience, but I wonder if it's not caused at least in part by excess heat.
Along with the advice that others on here have given me, this is my observation - I was smelting for the past two days with a cast iron pot and ladle over a hot fire stoked with seasoned hardwood, mostly white oak. The same wood, when stacked up and burned in my forge with just a draft from having the ash dump open, generates enough heat to get 1/8" steel red hot. That's hot!

[Bret4207]

When I changed from cast iron and steel pots to stainless my dross dropped by at least half. Could just be rusty junk combining with dog pee and 'baccy spit.

[alamogunr]

During my last smelting session, I didn't have a metal bucket to dump the clips that I separated from the melt so I dumped them onto a piece of galvanized roofing material. When they cooled and I started scooping them into a plastic bucket, I noticed that there was a lot of lead residue at the bottom of the pile. After shaking the clips to release the stuff, I ended up with about half of a gallon bucket. I'm going to see how much clean lead I can get from it. Probably won't be worth the trouble, but I hate to throw any lead away.

John
W.TN