I've only been casting for a few months, mostly its gone pretty well and I've figured out a few things. Today though was the first day with a new to me (aka. used) 5 gang mold 200gr SWC .452 from NOE. I'm running my lead about 650-700 degrees by thermometer and use a pretty large Lyman ladle that will hold enough lead to fill all 5 cavities and have some left over.
Questions: Today some of these bullets were perfect or close enough and then I started getting some with mold lines. I thought maybe I wasn't squeezing the handles tight enough or that I had something between the mold blocks. I checked that with my gloved hand and didn't see any junk in there. Holding the mold up to the light, I didn't see any gaps with light coming through. It started to get a bit worse I think as I went and the mold got hotter at the end some of them were getting "fingers". First time I've seen this but again, a new to me mold. I have other molds from NOE and haven't experienced this.
Fluxing and skimming? When I flux, stir it down and skim I'm (bees wax today) I get a some black junk that I skim off and try not to remove much metal. I guess I'm worried that I'm actually removing tin and antimony. Today my pot stayed "junky" which was also a bit unusual for what I've done in the past. The attached photo of the pot is at the end of the casting session and I've still got junk. I took my spoon and pulled it over to the side to make it bit more clear. Is that tin or zinc or ??? The lead I'm working with is second hand Wheel Weights. It had been used as race car lead. They took a valve cover and filled it with 100lbs of WW lead and I busted it up, melted it down and fluxed it when casting into ingots. So it is a an unknown mixture of whatever they had thrown into the valve cover when it was first melted down. Any feed back on what I'm seeing on top of my lead would be appreciated.
The third photo is of the mold. Am I opening it too soon? I'm pouring a good sized sprue puddle but getting some voids. What am I doing wrong? This is the first time I've cast with a 5 gang mold and haven't had this issue with single, double or the one triple molds I have.
Thanks