oley55
03-23-2021, 02:47 PM
First time casting with a 6 cavity mold and struggling a bit. Brand new MP 452-200 FP NLG, (https://www.mp-molds.com/product/mp-452-200-solid-6-cavity-mold-no-lube-groove/) cleaned and heat cycled in hotplate-oven a few times. Warmed to 400 degrees with sprue plate face down on aluminum block with drilled holes so the sprue plate would have full contact (pic). Alloy is COWW with 1.0% tin added. Lead temps 700-740 degrees (most at 740). As cast: .453" and 225.4gr. The weight is a little surprising, but I am OK with it since I was on the fence for choosing a 200gr vs 230gr.
Struggling to find the correct flow rate. Too fast and the sprue is running all over the mold, too slow and I get fine lines in the bullets. I like the slow trickle, but not with the lines (even with a fully up to temp mold). The sprue cutter handle worked it's self out and before I noticed it the wood handle split (sorta fixed now). I think I was squeezing it to hold the mold closed (I did have a couple pours where the mold was not fully closed). At any rate I stopped gripping the sprue cutter handle during a pour. One things for certain, if I do not have a hefty sprue puddle, the bases do not fully fill out.
Somehow I managed to get some lead splatters on the face of the mold and was getting finned bullet bases. Wiping it hot didn't work and had to stop until I could do a thorough cleaning. I think I may have gotten some splash splatters while cutting/dropping the sprue into the pot. I don't normally do that, but with those huge 6 cavity sprues it seemed like a good idea to instantly recycle them. I stopped doing that during my next session.
At various times, I had some trouble with the sprue adhering to the sprue plate and leaving behind residue surface lead, but could be wiped/rubbed off with a cotton rag. Not sure if that means the plate was getting too hot or what...?
I had a few occasions where for no apparent reason all or most of the bullets came out very rough (pic). Eventually I determined this only seemed to happen if or when I had left the bullets in the mold for a longer period while wiping off the top and sprue bottom. (I think...?) Over all most are a little rougher than I'd prefer. Wondering if I am waiting too long to cut the sprue, but I hate to see those sprue pull outs from cutting too early.
With the number of rejects I had, I suspect my production rate would have been far greater with a two cavity mold. I hope that's just the learning curve and not the norm for a 6 cavity.
Input and critical observations will be much appreciated.
Struggling to find the correct flow rate. Too fast and the sprue is running all over the mold, too slow and I get fine lines in the bullets. I like the slow trickle, but not with the lines (even with a fully up to temp mold). The sprue cutter handle worked it's self out and before I noticed it the wood handle split (sorta fixed now). I think I was squeezing it to hold the mold closed (I did have a couple pours where the mold was not fully closed). At any rate I stopped gripping the sprue cutter handle during a pour. One things for certain, if I do not have a hefty sprue puddle, the bases do not fully fill out.
Somehow I managed to get some lead splatters on the face of the mold and was getting finned bullet bases. Wiping it hot didn't work and had to stop until I could do a thorough cleaning. I think I may have gotten some splash splatters while cutting/dropping the sprue into the pot. I don't normally do that, but with those huge 6 cavity sprues it seemed like a good idea to instantly recycle them. I stopped doing that during my next session.
At various times, I had some trouble with the sprue adhering to the sprue plate and leaving behind residue surface lead, but could be wiped/rubbed off with a cotton rag. Not sure if that means the plate was getting too hot or what...?
I had a few occasions where for no apparent reason all or most of the bullets came out very rough (pic). Eventually I determined this only seemed to happen if or when I had left the bullets in the mold for a longer period while wiping off the top and sprue bottom. (I think...?) Over all most are a little rougher than I'd prefer. Wondering if I am waiting too long to cut the sprue, but I hate to see those sprue pull outs from cutting too early.
With the number of rejects I had, I suspect my production rate would have been far greater with a two cavity mold. I hope that's just the learning curve and not the norm for a 6 cavity.
Input and critical observations will be much appreciated.