I Got This Mold (wrinkled bullets)

[6mm250]

I bought a used Lyman 4 cavity mold , steel blocks. I tried casting boolits & they came out wrinkled , I smoked the cavities with my trusty Bic , the boolits are wrinkled. I put the mold blocks in my ultrasonic cleaner with Simple Green and ran it through several cycles then washed the blocks in acetone , smoked the cavities again & still got wrinkled boolits. I always preheat the mold not only that but I'm getting wrinkles even after several pours. I've tried setting my pot to high heat , low heat and in between heat. The alloy in the pot is about half & half pure lead/coww with about 2-3% tin added. This same pot of lead will make beautiful boolits in any of my other molds except the Lyman 4 cavity.
Should I throw this Lyman mold overboard the next time I drive across a bridge somewhere ?


Mike

[Springfield]

How to you pre heat the mold? Some things work better than others.

[rr2241tx]

No need to make it sleep with the fishes, you just don't have it heated up yet. Big iron blocks take a long time to heat up. You didn't say how big the bullets are, but guessing from your handle that they might be pretty small, you may need to change your casting pace to get more heat into the block each time as well to keep it from cooling off.

[6mm250]

The mold is Lyman 358477 , 4 cavity. I preheat by putting it on top of the pot.
I don't experience these problems with Lyman 35891 , 4 cavity , using the same technique/alloy.

Mike

[ShooterAZ]

Try using a hot plate, or on an electric stove.

[JonB_in_Glencoe]

every mold is different, you're 358477 just needs to be hotter...it's that simple.

I really like to use a Hot Plate (thrift store $1) to preheat molds.

[fcvan]

Back when I still smoked molds, I used wood matches. The light soot had no oily content you can get from things like lighters or candles. Many years ago I learned that scrubbing a mold in hot soapy dish soap with a toothbrush and a hot water rinse was all I needed. The last 15 molds I've bought, Lee, Lyman, SAECO, and RCBS included, have never been smoked and dropped clean wrinkle free boolits the first cast.

I cast with a Lee Pro IV 10 pounder. I cut out a tin can lid that fits over the top of the pot. When I set up to cast I put the lid on and set the mold on the lid. When the pot is warm so is the mold. A clean mold works great when it is up to temp. A good steel mold holds temp better than aluminum but the alum mold can be brought up to temp pretty fast. Try cleaning the mold, skip the smoke, and pre-heat before casting.

[6mm250]

Looks like a hotplate will be my next purchase.

Thanks

Mike

[Pilgrim]

Get a bronze brush (looks kinda like a toothbrush) and scrub the h@$& out of the vent lines, then clean again with acetone, reheat and try again. A second problem might be cured by the first solution. Some soaps leave a residue you really can't see that can screw things up. Rinse with boiling hot water, or simply hold the blocks open in a pan of boiling water to get rid of any films that may remain. Acetone doesn't dissolve everything and what you have left on the blocks may be one of those. In any case, if you are getting wrinkles, the mould probably isn't venting properly. FWIW Pilgrim

[osteodoc08]

Heat. And more of it. My iron/steel molds take a few casts even after being on the hot plate to get up to temp. Once ya get me going though you can churn out some serious piles of boolits.

[bhn22]

A molds not hot enough to use until it's around 300 degrees, sometimes more. From a cold standing start, that's perhaps 45 minutes to an hour sitting on top of the pot. One simple way to tell is to touch the sprue plate pivot with beeswax. If it melts immediately, you're probably ready to go, or close to it. And it sounds like you still have some residual oil trapped in the pores of the metal. A hot bath and a scrub with a toothbrush in dish detergent (without moisturizers) and a boiling hot rinse should impress it. I don't know what temp you're using, but I always had to run the big Lymans at 700 or more to keep them uniformly heated.