Thoughts on casting...

[45man]

Set the heat at 600°, get a thermometer if needed. DO NOT FLUX and skim the surface. If there is zinc it is like oatmeal and you can get most out. When you smelt batches into ingots, do the same. Keep at 600° and skim before fluxing.
To cast pure lead you need more heat and I cast balls at 800°. There is no need to flux pure lead, just keep the surface clean.

 

[Eutycus]

Set the heat at 600°, get a thermometer if needed. DO NOT FLUX and skim the surface. If there is zinc it is like oatmeal and you can get most out. When you smelt batches into ingots, do the same. Keep at 600° and skim before fluxing.
To cast pure lead you need more heat and I cast balls at 800°. There is no need to flux pure lead, just keep the surface clean.

I'm a little puzzled on your melting directions. Lead melts at 621 degrees. 600 would only get the lead hot but wouldnt quite get it to the melting point. Then if you did raise the temperature to 800 any zinc in the mix would melt (787 degrees, I think)

 

[Eutycus]

621 degrees are needed to melt lead, what am I missing?

 

[Carbon 6]

The lead will melt the fastest and temp will recover the quickest if the lead is in small pieces and are completely submerged in molten lead. I run my pot slightly hotter and add as soon as the level drops far enough for more to be added. This allows for minimal or no interruption in pouring.
I can pour really fast, so in essence I use lead additions to cool the lead temp.


Smo, You might want to melt and clean your lead before putting it in your casting pot. it appears quite contaminated.

 

[smo]

Thanks C6 ,
I'm just going too break out the fish cooker and another melting pot.(cast iron)

I think a contaminated pot is a lot of the issue.

 

[Eutycus]

Just how do you clean a contaminated pot. Wire brush or wire wheel on a drill?

 

[smo]

Just how do you clean a contaminated pot. Wire brush or wire wheel on a drill?

That’s what I did, I had a brass bristle wire cup brush .
Chucked it up in my battery drill and went to work, this was after scrapping the brownish crust from around the interior walls & bottom of the pot.

I polished it up nice and clean, only a small amount of the brownish stain remained visible.

It just would not come off with the brass brush or a hand steel wire brush.

But I would say the pot was as clean as it’s going too get.

I thought the brownish stain was dirt/ mud from some old sinkers I had melted a month or so back.
But now I’m having my doubts about that.

 

[Carbon 6]

I ruined a bottom pour pot by using it to melt lead that hadn't been cleaned.
Now I melt all my lead in a cast iron pot and remove the dross, then I make nice clean ingots for my bottom pour pot.

I also leave lead in the pot when not in use. and melt some beeswax on top of it to prevent oxidation. I also coat the visible inside of the pot too.

 

[smo]

I ruined a bottom pour pot by using it to melt lead that hadn't been cleaned.
Now I melt all my lead in a cast iron pot and remove the dross, then I make nice clean ingots for my bottom pour pot.

I also leave lead in the pot when not in use. and melt some beeswax on top of it to prevent oxidation. I also coat the visible inside of the pot too.

Do you use bees wax to coat the pot?

 

[Carbon 6]

Yep.
Automatically fluxes upon startup. not meant for indoors though, as it smoke a lot until you ignite it.

 

[Carbon 6]

I wonder if you had tin in the mix.

 

[smo]

I wonder if you had tin in the mix.

That is my suspicion on the first balls that turned grainy.

After that pour is when I cleaned out the pot and wire brushed the interior lining.

The next lead I melted was a box of new .535 Hornady balls...

The last pics I posted , with the brass/ gold colored dross...

Here are a couple of the balls from that lead...

The top one has a blueish color & the bottom is more of a brass / gold color,
These were out of the same batch of lead from the Hornady balls .

The only difference was in the temperature setting , the blue coming from a hotter setting...

 

[Eutycus]

Tin should only effect the hardness, I think. It mixes easily with lead doesn't it? Like Antimony.

 

[Carbon 6]

Tin is about 1/3 lighter than lead, that's why I asked about the weight of the balls.
In alloys, tin is used in very small amounts.

 

[smo]

Sorry C6 I haven’t gotten around to the weight thing yet....

But maybe I have...,
Come to think of it in another thread I had poured some .530 ball that ran as much as 10 grains difference in weight.

If I remember correctly , that was when I first put some of the original material mentioned in this thread in the pot and strange things started to happen.
Not the Hornady lead balls.

 

[nhmoose]

The colors you have there is very hot plain or near pure lead. Tin makes lead balls and bullets shiny. Again over heated lead.

 

[smo]

Thanks NHM,

I’ve noticed my pot heat cycling quite often , it’s 8 or 10 years
old so the thermostat may be going out.

I’ve always cast with it on 4-5 setting without issues until recently.

As soon as I get a chance I’m starting with everything new and using a lead source that I’ve had success with in the past.

I’m going to use a propane burner, cast iron pot using low heat.

Is the gold colored dross normal with high temps?

 

[Carbon 6]

Is the gold colored dross normal with high temps?

Yes, I get it quite often.

As your mold heats up from casting and your pot empties, the lead temp will rise. With a bottom pour you begin to notice pooling on the sprue plate, sticky lead, and frosting of the balls.
If this happens I usually add some more lead and switch molds, allowing the one I was using to cool off.

 

[Griz44Mag]

Just how do you clean a contaminated pot. Wire brush or wire wheel on a drill?

All of the above. Try to NOT breath the dust, and do it outside.

 

[smo]

Thanks C6,

This was a first for me, I’ve never had lead act like this before.

It’s very possible the pots thermostat is shot...
and temps are running high even on low.