How many heat cycles for a new 6 cavity aluminum mold?
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How many heat cycles for a new 6 cavity aluminum mold?
Three works for me.
Certainly more than one. I have one Lee that has been thru 8-9 cycles & still gives me fits.
All different for sure. NO TWO A LIKE!!!
Go thru a couple then let it get good n hot, hose it out with brake cleaner and try it out.
There's so many variables with heat, alloy, pour rate, etc. there isn't a one size fits all answer.
I've never had a mold that I couldn't take out of the box and make good bullets first session. That includes lots of Lee molds.
As for how I clean my mold and works for me, is I use the tooth brush with rubbing alcohol and let air dry and then .Preheat your mold on a hot plate then run your alloy hot . When the boolits is frosted then you lower the heat on the pot some.I to not go by what temp to cast at . Just what the alloy and mold will tell me I go by,
I just blast them with brake cleaner and start casting. Seems to work. If it is a boolit I like, I "heat cycle" it plenty of times in a short period. Trying hard to wear out my Lee 6 banger copy of the HG68...
I'm with trapper on cleaning but even if the pot temperature is right (I cast at a controlled 700F), running the mould too fast will overheat it. I run three moulds at a time to allow cooldown and proper suck in during cooling. I don't preheat, just start casting. Good luck
I've read here that most new molds need to be cleaned of cutting, lubricating and/or rust preventing oils prior to use, and that heat cycling new brass molds helps build a patina that helps casting, but do aluminum molds really need heat cycling? I thought newly machined aluminum alloys form invisible but protective oxide coats almost immediately, and that just oil and maybe burr removal of the blocks plus appropriate lubrication of the pins, hinges and sprue plate were all that's needed.
I have one brass mold still NIB, everything else is aluminum in the form of six and eight cavity gang molds. Once treated as I described above, and once I learned to preheat, get my alloy temp right, and maintain a good cadence, they all dropped good boolits in the first session.
Heat cycles? I just clean them and use them!
NOE recommend heat cycling before use and I have followed their advice. Lee molds I clean and lube and start casting. I do pre-heat on a hotplate and generally get good bullets on the first or second pour. Experience says the Lee needs a bit hotter alloy than the NOE, suspect the lighter Lee cools quicker. A properly working mold is a joy to use, one that is not tends to have you using words you wouldn't use in front of the ladies and children.