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View Full Version : Third smelt - with a surprise



theTastyCat
03-08-2011, 11:29 PM
So I embarked upon my third smelting session today. Loaded up my first potful of WW, mixed in a handful of sawdust, fired up the fryer and went to town. Heated the mix to about 725, got things good and soupy, removed clips and sawdust ash, fluxed a couple of times, and brought the temp down to 650. Once it was sufficiently fluxed, I heated my ladle and got a big ol' scoop of lead and had just begun pouring it into the ingot mold when a sharp, loud sound happened, and I saw something go flying out of the corner of my eye. My mind instantly raced through options: Wow...was that the tinsel fairy? She was really polite - nothing like the guys on the forum have described. Maybe she likes me. But what the heck? I didn't add anything to the mix - did a bird pee in the pot?

Thankfully, my drawers remained unsoiled and I was able to finish pouring the ingot without branding myself.

Well, my mom happened to be standing nearby, and told me that my thermometer face had burst. I was puzzled; today was only the third time I'd used it, and the temp was at 650 when it happened. My previous smelt was the first time I used the new nuclear fryer, and the temp shot up (quickly may I add) to 950 once, which provided me with a nasty zinc alloy. But the thing reads to 1000, so surely it can handle that?! Here's a pic of it now.

http://i930.photobucket.com/albums/ad145/thetastycat/teltru.jpg

I wasn't totally sure that I trusted it - I seemed to be getting molten lead before it read 635, and when trying to harden the last half-inch in the pot before adding more, it stayed liquid far below 635, and yes, the thermometer was in the lead. So maybe I just had a bad apple.

One thing that's weird is that after it popped, the surface of the lead turned blue/purple, which I read may be tin or antimony or other good stuff coming out of the alloy, but I thought that happened at much higher temps. Also, as it continued to cool, the surface turned almost light brass-colored. Could it be the mix was super-hot and my thermometer was off?

I e-mailed TelTru today so hopefully they're take care of it for me.

Of course, just as soon as the second pot was almost molten, a few drops of rain started to fall, so I shut 'er down. :violin: Dangit, I was looking forward SO much to spending the afternoon smelting. I seriously love turning nasty WWs into beautiful ingots. I'm taking great pride in getting the temp just right to where very little if any lead comes out with the clips and dross. I LOVE this!

So maybe Friday will be my first smelting session where I get more than 20# of ingots :2 drunk buddies:

Suo Gan
03-09-2011, 02:39 AM
I think you got a lemon too.

gray wolf
03-09-2011, 10:50 AM
Was the probe into the melt past the little band on the stem? ( about mid point )
Like it says in the directions. I don't know how important that is but it says to do it.
I tested mine in boiling water to start off and it read 213* so I think the low end is good.
I have seen many a thermometer go over max and they just seem to peg out someplace past the last digit. Never saw one pop the bezel .

midnight
03-09-2011, 12:36 PM
My guess is there was a slight amount of condensation from moist air under the lens. The dial will get over 212 degrees while casting. The resulting water vapor popped the lens off.

Bob

theTastyCat
03-10-2011, 01:20 AM
E-mailed TelTru and they said to send it in and they'd replace it. I'm still trying to smelt my many buckets of WWs, and MiHa hasn't made my mold yet, so I figure I can smelt OK without a thermo. But I'll be grateful to have it back by the time I'm smelting!