milrifle
09-10-2012, 09:34 PM
This weekend, I smelted 100 lbs of wheel weights. This is my third batch, but the first time I've used my new propane burner. Before, I was using a propane camp stove, but it lacked BTU's and made for slow melting. On the last load in my pot, I noticed a yellow tinge to the melt. Of course, I panicked! It was zinc. Just had to be. How could we have let this happen. We called ourselves checking every last weight with a pair of dykes. Still, several steel weights got through, so letting zinc ones get through was also possible. What's worse, my new burner is capable of getting the melt hot enough to melt zinc. The old camp stove would barely melt lead. Boy was I upset. I had read that zinc will make lead hard to pour and give it an oatmeal consistency. I dipped my ladle in the melt and tried to pour it back into the pot and the stuff wouldn't hardly pour out of the ladle. It wouldn't pour out the little pour spout in the edge. It kinda ran out all the way across the edge of the ladle. Wierd. Oatmeal? Well not really, but I suppose the dross KINDA looked like oatmeal. It just HAD to be zinc. And it wasn't me that let it through either. HAD to be my wife's half hearted attempt at sorting. I never made the accusation, but I KNEW SHE DID IT! Well, I shut the whole operation down in disgust and came back into the house.
Then I got on here and read up on zinc contamination. I read the entire 8 page long Gold, Blue, Purple thread and came to the conclusion that maybe........well maybe everything is still OK. Maybe I just got it too hot. I don't have a thermometer and the new burner certainly has the capability of getting things hot and hot in a hurry. Under the dross was a perfect mirror, but dipping the dross off only lasted a few seconds before it was all yellow and ugly again. Still, probably just got it too hot.
So tonight, I go out and melt my ingots down again, being careful to turn the fire down as soon as the ingots turned to liquid. I fluxed everything again. Didn't get much. Poured up my ingots again. I even poured a couple of bullets just to see how everything filled out. They looked fine. Everything is OK.
I do have a question. Why did the melt not want to pour out of my ladle yesterday? My guess is that it was so hot that it was trying to oxydize and turn to 'dross' in mid air.
Then I got on here and read up on zinc contamination. I read the entire 8 page long Gold, Blue, Purple thread and came to the conclusion that maybe........well maybe everything is still OK. Maybe I just got it too hot. I don't have a thermometer and the new burner certainly has the capability of getting things hot and hot in a hurry. Under the dross was a perfect mirror, but dipping the dross off only lasted a few seconds before it was all yellow and ugly again. Still, probably just got it too hot.
So tonight, I go out and melt my ingots down again, being careful to turn the fire down as soon as the ingots turned to liquid. I fluxed everything again. Didn't get much. Poured up my ingots again. I even poured a couple of bullets just to see how everything filled out. They looked fine. Everything is OK.
I do have a question. Why did the melt not want to pour out of my ladle yesterday? My guess is that it was so hot that it was trying to oxydize and turn to 'dross' in mid air.