How obvious is it when you get zinc smelted in you pot?

[zanemoseley]

I smelted about 200 pounds of sorted wheel weights today. I sort them pretty well but a couple zinc weight always get through that I skim out. Most everything went smoothly today. Only problem is I put in too many weights to start, about 75 pounds worth. This made for a hot smoky mess, too many clips to skim off at once. In the process I think I ended up getting a bit hotter than I like. It got smoother as I added a boat a time to the melt, much easier to control the temp and make sure I get out all zinc.

So my question is how obvious it is when zinc accidentally gets smelted in with the pot? Ruining a pot would suck but ruining 200 pounds would be heartbreaking.

Good news is I got about 200 pounds of ingots from $100 of weights, pretty sure all zinc free.

[lightman]

Its hard to say. Its pretty obvious. It also tales a lot of zinc to ruin 200# of lead. Prolly more than you would get by accident using an average amount of caution. Sorry, not an exact answer, but there is not an exact answer.

[hickfu]

Here is what zinc looks like in the pot... at only 650 degrees there should not be any oatmeal floating on the top like this zinc..

149268

[MrWolf]

I have dumped a full 5 gallon bucket into my cutoff propane tank with no issues. Think in my over 1,000 lbs of smelted lead I only found one or two zinc ww's. They were just sitting on top with the clips. I do side snip each one but sometimes 1 or 2 will get by me. I do watch my temp and gas flow. My thermometer is held in the pot with a bent hanger that allows it to hang lower in the pot.

[zanemoseley]

I do wish it was easier to get an accurate real time temperature of the alloy while smelting. I've got the RCBS thermometer with the wire handle. Problem is even with gloves by time the thermometer gets up to temp you arm is getting more than toasty, especially if I try and do it while the burner is on.

[zanemoseley]

Doc, is that yellowish green liquid a byproduct of the zinc melting in the lead or is that some type of flux? I've never noticed any oatmeal like stuff floating, more just residual trash that forms a smooth skin on the surface I skim off. Does skimming off the "oatmeal" remove the majority of the contaminated zinc in the alloy? I wonder how much zinc it takes to ruin lead? For instance if you had a 2oz zinc weight get melted in 50 pounds of lead (800oz) then you'd have .0025% zinc content.

[44man]

It does look like oatmeal and if you flux, it will blend in. Makes real funny rain gutter boolits.
keep the lead at 600° and skim the stuff off.
You can remelt and keep the temp low, the junk will again float.

[zanemoseley]

So I gotta ask, what the hell is a rain gutter bullet?

[Mr Peabody]

So I gotta ask, what the hell is a rain gutter bullet?
Me too, sounds nasty

[toallmy]

Rain gutter That sounds like some of the bullets I have cast. What about the little smiles on the cast bullets,or are thay a little unhappy face

[toallmy]

Rain gutter That sounds like some of the bullets I have cast. What about the little smiles on the cast bullets,or are thay a little unhappy face.

[stu1ritter]

What happens to bullets that are cast with some zinc in the lead?
Stu

[Foto Joe]

I gave up on sorting a couple of years ago. Now when I smelt I do sort out the first five or ten pounds just to make sure that my starting melt is nothing but Pb. Once that starts to melt though I just dump in what ever is on the table. By adding new material you're keeping the temp down which prohibits any zinc from melting.

I will say that you HAVE to PAY ATTENTION when you're doing it this way but it sure beats sorting hundreds of pounds of filthy weights.

[44man]

They look galvanized! Like the old fashioned gutters.

[hickfu]

Doc, is that yellowish green liquid a byproduct of the zinc melting in the lead or is that some type of flux? I've never noticed any oatmeal like stuff floating, more just residual trash that forms a smooth skin on the surface I skim off. Does skimming off the "oatmeal" remove the majority of the contaminated zinc in the alloy? I wonder how much zinc it takes to ruin lead? For instance if you had a 2oz zinc weight get melted in 50 pounds of lead (800oz) then you'd have .0025% zinc content.

Yes skimming off the oatmeal looking stuff gets rid of the majority of zinc but it will leave behind a certain percentage I think up to 2% which is not good. But with fluxing you can get the % down to an acceptable level (or you can mix it with known good alloy to cut it down further) I have 400lbs of contaminated (got it off a dumb@55 on feebay who said it was clean) Im going to treat it with sulfer and then only use it for casting shot for the 12 gauge.

If you are not seeing oatmeal on the top and your temps are at or below 650 then its most likely you are not contaminated.

[44man]

I had water pipes and cable sheathing and got some ingots with the look and RB's were coming out funny. I skimmed it and everything works now. I don't know if it was zinc or calcium or how zinc could be there at all.

[JonB_in_Glencoe]

I had Zinc contamination once.
I posted some photos of what the ingots looked like.
http://castboolits.gunloads.com/showthread.php?155778-my-first-Zinc-contamination-in-WW-smelting&highlight=

[Markbo]

I did the sulfur thing once. Once.

Even with a respirator it was tough and the neighbors were not happy!!! It works, but it is a smoky, smelly mess.