I posted a while ago about having trouble with my 314299. Well, I did some of your suggestions, and here is the result. I casted about double this, but had a 50% reject rate. It looks like there is either frosting on the boolits or dirt or something in my lead ... I don't think it's frosting because ones at lower temps (less than 700 degrees) look exactly the same.. Also.. some of these do have definite frosting (can see the grain patterns), and it is different. Any ideas why these look kind of crappy? Are these ok to use?
Every once in a while I nice shiny one will come out (but it always has some other defect).
What I basically did to the mold was clean with acetone and a brush. Then brake cleaner and a brush. Then I boiled it in soapy water followed by a rinse and a boil in clean water, blew it off and dried it, and finally I gently spun a phosphor-bronze bore brush in the cavities.
The most common defects were wrinkling and random voids on the surfaces.
These are 9 lbs of .22lr range lead mixed with plus metal and tin solder. I goofed and got the tin too high, so it should be something like 2-3% antimony and 5-6% tin. I cast in about 4 increments, increasing the temp by 50 degrees from 750 to 950 degrees... 950 actually had the lowest reject rate... a couple came out definitely frosted from 950, but most looked just like all the other non-rejects from lower temperatures. I do flux the pot (bottom pour), I use about a half pea sized piece of paraffin and mix with a wooden dowel. I do not skim the top unless it gets too much crap on it.
The range lead is collected from a .22lr only range by yours truly, and comes mixed with all sorts of dirt and rocks. To smelt I put it all in a dutch oven on an electric melter I made, and fluxed/stirred using a wooden stick. Cleaned off the crap and ladled it out from the top into muffin tins.
Never watched anyone else cast or smelt, and all I've learned has been from you guys... so any suggestions will be welcomed.
The pictures are huge so you can download and zoom if you need to get a better look. Thanks!
Edited to add:
The bases are also bad. There appear to be very large and definite grains on the inside of the boolits. I do not think it's tearing, because I noticed it while casting and the amount of time before cutting the sprue had little effect. This would mean the solidification time is too long, correct?