1st smelt...am I contaminated!?! (Dialup warning)

[jameslovesjammie]

I did my first smelting session, and was really surprised about the amount of steel clips ended up with compared to ingots.

http://i26.photobucket.com/albums/c129/jameslovesjammie/gun%20stuff/Casting%20Stuff/P1010943.jpg

This is a really fun hobby, but I am concerned that I may be contaminated with zinc. According to my RCBS thermometer, I was smelting between 600 and 650 degrees. I did notice when I was scooping out the steel clips that I had some chunky stuff, but I scooped it all out. I backed my temperature down to where the thermometer said 550 and scooped out any remaining chunky stuff and clips. When it was all done, I raised my temp to between 600-700 degrees and began casting my ingots.

I noticed that some of my ingots would break when they hit the pan,

http://i26.photobucket.com/albums/c129/jameslovesjammie/gun%20stuff/Casting%20Stuff/P1010944.jpg

And some of them cracked a little.

http://i26.photobucket.com/albums/c129/jameslovesjammie/gun%20stuff/Casting%20Stuff/P1010945.jpg

Are these signs of zinc contamination, or did I just dump them out before they were fully cured?

My ingot mould was a cast alumium Danish Donut pan, my pot was a 8 quart cast iron dutch oven, and my fire source was a fish frying kit I got from Walmart for $40.

http://i26.photobucket.com/albums/c129/jameslovesjammie/gun%20stuff/Casting%20Stuff/P1010946.jpg

http://i26.photobucket.com/albums/c129/jameslovesjammie/gun%20stuff/Casting%20Stuff/P1010947.jpg

http://i26.photobucket.com/albums/c129/jameslovesjammie/gun%20stuff/Casting%20Stuff/P1010942.jpg

If it is zinc contaminated, can I remelt my ingots at a lower heat and with any hopes of recovering the lead, or is the whole batch garbage?

Thanks for your help guys!

James

[targetshootr]

I think Zinc is yellow-ish and melts at a higher temp. The ingots probably didn't cool off enough.

[imashooter2]

Nothing amiss in those ingots. Drive on.

[imashooter2]

Oh, and resmelt that "chunky stuff". You're throwing away lead.

[13Echo]

Wheel weight alloy goes through a "mushy" phase when it melts or solidifies. If you dump your ingots while the center is still in this stage the ingot may fracture and give the appearance seen on your ingots. Looks like wheelweight alloy to me.

Jerry Liles

[jameslovesjammie]

Thanks for the help guys! I will remelt that chunky stuff too. I was just concerned, as I've read so much about zinc on here that I kinda got scared. I did find a decent amount of zinc when I sorted, but I've been known to occasionally miss something.

Thanks again! I'll do some more smelting tomorrow!

[docone31]

You dumped too soon. Melt em back up, and get to casting!
With boolitts, your mold helps the cooling so when a casting is dumped, it does not crack. At least not like those.
Larger ingots need more time to cool.
Cast away. No need to remelt, just melt em for castin.

[Beaverhunter2]

I can definitely support waiting until your ingots cool down a bit before you dump them. I got in a bit of a hurry a couple months ago while smelting and, not realizing that there was only a "skin" over the top of the ingots, poured the better part of 4 lbs onto the floor and the previously cast ingots. Glad I wasn't working in sandals!

John

[copdills]

Thanks for posting with pics James , I haven't casted ingots yet and this along with all the great information shared will help me out in the long run

Thanks copdills

[RustyFN]

I smelt at 650 to 700 degrees. I start scooping the clips at 650. I don't think you need to worry about zinc melting until you go over 750 degrees. I have had very few zinc weights but they have all been on top and easy to scoop out.
Rusty

[imashooter2]

With a pot the size pictured, there's plenty of time between WW melts and zinc melts to get the zinc out of the pot. PLENTY of time.

[JIMinPHX]

If you only have a small portion of your thermometer in the melt then your reading is not accurate. Your temperature was actually higher than the dial read.

[Christian for Israel]

if you add flux before scooping out the clips the chunky stuff will release it's lead and you'll have less dross to remove.

[jameslovesjammie]

The tip of my thermometer sits about 3/8" from the bottom of the pot, which is an 8 quart pot. When the lead was molten, and clips were removed, it was about 1/2 full. I would have suspected a true reading.

[JIMinPHX]

The tip of my thermometer sits about 3/8" from the bottom of the pot, which is an 8 quart pot. When the lead was molten, and clips were removed, it was about 1/2 full. I would have suspected a true reading.

I was just going by what I saw in the picture. Half in should be pretty close to a good reading.

[Blammer]

I smelt at 700 degrees and zinc floats out.

You're good to go.

[Hang Fire]

Not to worry, appears the norm when ingots are dumped too hot. You also may be chucking out some melt with the trash there.

[trickg]

A question - is there a way to estimate the temperature of the melt if you don't have a thermometer?

I ask because I don't recall my Dad ever using a thermometer - then again, he smelted and casted at a time when I don't think any clips were made out of zinc, so it was probably less of an issue for him. He also probably had a pretty good idea based on how much flame he had on his burner what the melt temperature was going to be.

[cbrick]

jameslovesjammie, nice pictures, looking forward to seeing some photo's of boolits cast from those ingots.

I go along with the thought that you simply dumped the ingot mould before the alloy had cooled enough (glad I've never done that [smilie=1:). Your methods sound and look just fine, get that boolit mould out.

Rick

[imashooter2]

A question - is there a way to estimate the temperature of the melt if you don't have a thermometer?

I ask because I don't recall my Dad ever using a thermometer - then again, he smelted and casted at a time when I don't think any clips were made out of zinc, so it was probably less of an issue for him. He also probably had a pretty good idea based on how much flame he had on his burner what the melt temperature was going to be.

Sure! Turn the heat on and don't walk away. When the vast majority of the weights melt, give the pot a stir. The steel clips and any non lead weights will float to the top. Skim them out, flux and cast ingots.

[44man]

We had a guy at work that was contaminated. He had silver in his teeth, steel in his hair and lead in his ass! :mrgreen:

[trickg]

We had a guy at work that was contaminated. He had silver in his teeth, steel in his hair and lead in his ass! :mrgreen:
In my time we could have smelted the lead out of the butts of a lot of the people I have worked with!