Refried Beans on my lead.....

[Sonnypie]

OK. So I'm real new to this.
I've been banging away making my 30 caliber boolits with Rotometals Lyman #2 formula.
I added a little 60/40 solder for the flux and went to get the Grandson from school. (Turn the furnace down when idle next time. Check)

When I got back there was this odd layer that looked like dirt on the surface of the pot of molten metal. It was hard like baked clay or dirt, and looked like refried beans. Chunky and jagged.
It took an awl to break through it, and I managed to carefully break it up and remove it into my slag can.

I'm pretty certain the batch got too hot during my absence from the shop.
I'm using a Lee Pro 4 - 20 furnace and was running it at 7 1/2, but had turned it up to 8 a little while before and was casting away and putting the sprue back in as I went along.
That's why I figured it overheated during the idle time with no cooled sprues to hold the temperature down.
Once I got the junk off and out, the metal appeared ok and cast like it had been for the duration of the session. I did a huge amount of boolits today.

What was that crust?
Did I burn up the Tin or Antimony in that batch?
I have never seen anything like that before.

Feel free to slap me upside the head. :killingpc [smilie=1:
Dad probably would have.

[btroj]

I would have broken that stuff up, fluxed the heck out of it wi sawdust, and stirred away.
That was your tin and antimony. Not all of it but enough to potentially matter.
I find that higher tin/antimony alloys frequently get an oatmeal looking dross initially when melted. Fluxing gets this stuff back where it belongs.
And adding some 60/40 solder as flux? Not gonna work. Try sawdust, works very well. All you did was add tin. And you added tin to a pretty darn tin rich alloy. Don't waste your tin trying to use it as a flux.
Use the search function here and read up on fluxing. Your solder will appreciate it.

[Sonnypie]

OK, will do.
The solder is rosin core, that's why I added the smidgen.
I just wanted a little.
I have used some of my ground walnut shells once as a flux (About a teaspoon).
So basically, I just burned some of the Sn and Sb out of the batch? Making the alloy softer?
I'll revisit the slag can and see if I can reintroduce it.

I'm casting for rifle boolits, and hope to push into the 2000 FPS with these.
Thanks!

[randyrat]

The re fried beans is the FLUX floating on top of the mix. Take a hand full of dried leaves or saw dust put it on top and soak it up. then discard it in the garbage, bagged well. You didn't hurt anything.

[Sonnypie]

Thanks Randy,
That was the strange part about it. The brown stuff was hard and formed a crust over the melt under it. I had to physically break it up and knock it down off the furnace walls.
The metal was oozing through it a little.
It looked and acted like dirt, or overdone refried beans, to me.
It also did not appear to want to melt as I was spooning it away.

Like I said, I'm new to this. Last time I cast with lead was as a kid making toy soldiers. I'm a 61 year old Grandpa now. ;-)

Anyhow, that batch has gone into boolits. And the furnace is full of newer melt (cold now) waiting for me to start up again.

Walnut shell (Ground)...
In lieu of sawdust, I have quite a bit of this for my tumblers. I only tried it once so far. (It's Lizard Litter from Petco. Ground English walnut shell.)
Any opinions about using it for fluxing?
It seemed to work OK when I tried it. At least I think, in my limited experience.
I've read up quite a bit here, and with Glen Fryxell's book (http://www.lasc.us/Fryxell_Book_Contents.htm) That's where I came up with the idea of putting a big punch of walnut shell in for fluxing.

I don't think I will be using much, if any, of the solder anymore. (Other than as a tin source.) If I didn't have 5# rolls of it, I probably wouldn't have in the first place.

Ground Walnut Shells for fluxing?

[btroj]

Walnut shells would work for fluxing.

I did not know, or even think of, rosin core solder. That would make a mess if it set up like that. Randy is right, you hurt nothing at all.

[Sonnypie]

All is well.
The ground walnut shells worked great. I put a big spoonful on, stirred well, and the pot-0-gold stayed great.
... I smell like I've been sitting in a smoker, and the entire garage has this wonderful smoke aroma...
And the wife stuck her head in the shop and said, "Are you burning something???"
Through the haze I replied, "Yeah." And kept on casting boolits.
But it worked great!

I have to fix the vent fan motor....
...must...have...more.....air....:veryconfu

Thanks!