Wrinkled bullets

[AlHunt]

Get your alloy and mold hotter until you see frosty bullets (this assumes you have antimony in your mix). If you then have frosty AND wrinkled bullets, you've got a contaminated mold. I just went through this yesterday with a new aluminum mold. Wrinkle city up to about 800F. Once the mold was hot, I let it drift back down around 700F. The 4 cavity mold held it's heat and kept dropping frosty, wrinkle-free bullets.

My mold prep was Dawn Dish Soap, dry, acetone flush then 3 heat/cool cycles to 400F.

On the subject of brake cleaner - be sure to use non-chlorinated. The chlorinated stuff leaves some kind of residue behind. Another lesson I learned the hard way. The next time you get chlorinated brake parts cleaner on your fingers (accidentally, of course), rub them together after it dries and you'll feel it.

[Burnt Fingers]

I finally got a chance to cast using my new MP aluminum mould and ended with wrinkled bullets. I've tried different lead temperatures, heated the mould, cooled the mould, cleaned it twice with brake cleaner, even alternated between dipping and bottom pour. Finally, I switched to my old Saeco mould and got perfect bullets. The ones on the left are from the MP mould, the ones on the right are from the Saeco mould. I'm beginning to believe I'm not smart enough to cast with an aluminum mould. Any ideas would be appreciated.

1. Get the mold HOT
2. Keep your melt temp around 710-720
3. Lightly smoke the mold cavities with a butane lighter.

[bangerjim]

Your problem is NOT oil! You scrubbed it MORE than enough it sounds like. I have never scrubbed a mold.....EVER!

Your mold and alloy are not hot enough.

Buy and use an electric hotplate to preheat all your molds to FULL casting temp B4 ever starting. I have been doing that for years now and I get perfect drops from the 1st pour, even with brass molds which LOVE heat. Sitting the mold on the edge of the pot is not hot enough and is just a waste of your time.

Also preheat all your feed ingots to 15-20F below liquidous temp of the alloy to minimize recovery time when adding more ingots.

That should give you perfect boolits. I sure does for me!!!!!!!

Good luck.

banger

[FLINTNFIRE]

Scrub it again is not going to hurt it , heat cycle it a few times will help , heat it to temp and melt to temp and cast till they drop the way you want them . And if it was casting that way but your other mold was dropping nice your melt was up to temp , and if both molds were as hot to start then other then mold material being different would only be residual oils in cavities , go back and give it another whirl and see .

[SoonerEd]

For MP brass mould I start at 750°, use a hot plate to preheat and cast fast till the boolits frost then back off till they have a very light frosting. From then in it throws good boolits. You should also heat cycle 3 to 4 times to get a patina going.

This has been my experience as well.

[fredj338]

Clean the mold well, get it hot, get the alloy hot. Many of my molds are alum. Some do require breaking in, but looking at the bullets, it like a heat issue.

[bruce381]

the wrinkled bullets just look way too shiny to me, which normally indicates mold is not up to temp yet.

yeah I agree go hotter and get a hot plate to pre heat mold like $15 on amazon