Lee C309-170 wrinkles

[DLCTEX]

I bought a new mold from Junior and tried it out yesterday. I gave it my usual bath with brake cleaner, dipped the mold in the melt to warm it up, and began dropping boolits with wrinkles. All wrinkles are on the sprue plate half and run from base to point, but not consistently, sometimes just on the bore riding portion.. I gave it another bath while hot, no joy. I cooled the mold and gave it a scubbing with Bon Ami, still wrinkled. I boiled it in water with a little dish detergent, wrinkles. I finally decided to burn it out by dunking the open mold into the melt( Lee pot cranked all the way up) for 30 seconds. When filled the sprue would not harden until I blew on on it, then the lead was still liquid when opened, so I colled it in front of a fan for a minute. Finally no wrinkles, but extreme frosting. More cooling produced boolits with speckling on the same half and lowering temps to my normal casting temp wrinkled again. With the heat back up, I water dropped boolits and wound up with 38 good boolits ,19 slight blims, and 9 rejects. I will give it another scrubbing with Bon Ami and try again. DALE

[Down South]

I wonder if Leementing the mould would solve the problem.

[Junior1942]

Dale, wrinkled bullets = cool mold. Crank up the pot and leave it high. And don't worry about frosted bullets--I like 'em!!!

[DLCTEX]

I don't think this is due to a cool mold as there is a slight blemish in the same spot even when the mold is too hot. This is my first time casting with an aluminum mold smaller than 38 cal., so maybe there is something different with the smaller cal., but the wrinkle and blemish in the same place and perfect on the other mold half leads me to believe that there is some contaminate in the mold. If both halves showed the problem i could buy the cool mold thought, but it would seem that the sprue plate half would tend to run hotter due to the steel holding the heat. I did lube with Bullplate before the first cast trying to keep away from the cavaty, but it may have crept in. If it is the lube, it sure penetrates the metal. We will see. I considered Leementing to scrub the surface metal away, but will do that as a last resort. I considered venting, but it still wrinkles with the sprue plate wide open. The saga continues. DALE

[Maximilian225]

I had a similar problem with a 45300RF.
No amount of scrubbing would fix it. Tried boiling it, no luck
Closer examination showed they didn't go all the way to the outside edge, and some had a burr in the cavity.Finally opened the vents up with the tip of the Xacto. After opening the vents up I cast a few and used them to polish the cavities with some toothpaste.
The wrinkles are gone on my bullets now.

[dromia]

As has been said I'd try opening up the moulds vent lines especially around the moulds blemish spot.

Its a Lee so fettling is the norm.

[DLCTEX]

Today I scrubbed the mold half that had been wrinkling with Bon Ami again, set the pot temp on 9, and warmed the mold with a 20 second dip in the melt. 110 nice lightly frosted boolits with no wrinkles. Turned the temp down to 7.5 about 2/3 of the way through and the boolits began dropping from the mold without even a tap on the rivot. Was it the cleaning, or the temp, or the odd recurring casting better with an overnight wait. I have wondered in the past if the contaminate oxidizes after being heated, and is removed or rendered inert. I don't care, as long as it works. DALE