PDA

View Full Version : Help a new caster figure out wrinkles in bullets



Smoke4320
04-19-2013, 10:19 AM
new here and too casting .. Been reading for at least a week now many many posts ..
Picked up some very good info ..
heres my problem

lee 4-20 bottom pour pot

new Lee 2 cavity 458 340 gr FN mold ..

tryed casting pure lead bullets got all kinds of wrinkles ..ran 600 to 800 degree trys .. many many trys over 2 days

mold was up to temp .. had problems getting bullets to drop no matter what temp I tryed

following the Leementing posts
I have used a box cutter to lightly open up the the air vents to outside of the mold
did the honing with cast boolits and fine valve grinding compount followed by comet ..

checked size of cast bullets and still measure the same so did not remove measureable amount of Aluminum

tryed adding 2% tin to mix

now bullets drop freely 90% of the time . Light tap drops all others

slowed down the pour stream

wrinkles much better but still not gone .. I getting complete fill out.. bands are square edged. just have wrinkles ..

also one side seems to be very shiny other side has about 1/4" wide verticle streak that looks frosted ..its smooth just not shiny like other side..

any advice would be welcomed ..

btroj
04-19-2013, 10:23 AM
Clean the mould again. Hot water, comet, toothbrush. Scrub it well. Rise, scrub again. I find many Lee moulds need a few cleanings. I have some that need a second cleaning after a casting session.
Did I mention cleaning?

bowenrd
04-19-2013, 10:32 AM
Has anyone mentioned start with a clean mold? Next step is get that mold hot, not warm, hot. turn up the pot temp and cast fast. When you start getting frosted looking boolits you should have good fill out and no wrinkles. Back off the temp a little and slow down your pace. Good luck.

swheeler
04-19-2013, 10:36 AM
Using pure lead set your pot on highest setting, preheat your mold on stove burner or hot plate. If I have a mold that needs cleaned real good I put it in a coffe can of mineral spirits or paint thinner for a day, remove it and scrub it good with hot water and dish soap using an old tooth brush.

wallenba
04-19-2013, 10:51 AM
Sounds like the heat of the melt is OK, yet the mold may need more warming. Invest in a hot plate if you don't have one. Clean that mold again. Other causes made by new casters are: Casting with cold air blowing on the pot, cooling the alloy as it pours. Having it drop too far from the spout to the mold, allowing it to cool some. Not having the metering rod opened up enough, taking more time to pour. This puts hotter melt on top of melt already cooling.
After the pour, let the mold rest a few seconds before you move it or rotate it. Even though it has hardened on the sprue plate, it may still be a lttle plastic in the cavity.

41 mag fan
04-19-2013, 11:01 AM
Did anyone mention a clean mold?? Clean it in hot water...I use a pot just big enough to put mold in, and boil it for about 5 minutes, scrub with a toothbrush, with dawn soap rinse, boil again, scrub, rinse and it should be good to go.
With a Lee I cast my first few fast, throwing them in my reject pile, after my 3rd or 4th cast when my sprue plate gets hot, I'll cast, cut my sprue, and leave the casts in the mold for a few seconds.
This helps with heat transfer to mold to get it up to temp.
Seems like with Lees molds a hotplate will get it hot but not to where it needs to be to cast good boolits.

wallenba
04-19-2013, 11:17 AM
Another thing about cleaning. If you have hard water, don't just air dry it, it may leave mineral deposits you can't see. Clean it with 91% rubbing alcohol, or better yet spray it down with CRC brake cleaner.

454PB
04-19-2013, 11:40 AM
I'll jump on the bandwagon. Clean mould, preheat, no "smoking the mould", and if you are lubing the mould, make sure the lube isn't migrating into the cavities.

Smoke4320
04-19-2013, 11:48 AM
Thanks for all the replys
before last casting I cleaned with toothbrush at least 3 times in hot water with soap .. then rinsed in hot water again..
I will try cleaning with brake cleaner and then scrub with dawn and toothbrush again ..
and heating mold on hot plate
again thanks for the replys

cs86
04-19-2013, 02:10 PM
I'm sure some have had good luck with break cleaner but I was told it doesn't work very well, and that hot water and soap, maybe even comet would be your better bet. I know smoking is a sin around here when it comes to molds but when I get fed up with all of the junk I smoke it and things turn out good. Depending on how picky you are, try a few things and decide for yourself.

btroj
04-19-2013, 03:03 PM
I use comet. Lots of comet, little water. I make almost a paste of the stuff and scrub the cavities well. Then rinse. Then repeat.
Comet is a much better degreaser than dish soap.

MtGun44
04-19-2013, 03:45 PM
+1 on comet.