Flawed boolits, temp or ?

[bdutro]

Bullets are dropping out of a Mihec H&G 503 mold with inclusions and/or wrinkles.

I cleaned the molds with mineral spirits and ran the alloy temp up to 700°F+. Mold temp was up there too but still wrinkly or poor fill out with rounded edges on the grooves or flaws in the nose.

A shot of Frankfort arsenal Drop Out helped so I cleaned and tried again. Same problems.

Should I clean with acetone or MEK? Alloy is ~20 lbs of clean, fluxed WW with ~8oz of tin solder added.

[Dale53]

bdutro;
Using hot tap water, a toothbrush, and liquid hand soap or Dawn dishwashing liquid SCRUB the mould cavities thoroughly. Rinse with VERY hot water and blot dry. Mineral spirits leave a deposit of lube on the mould - NOT good.

If the MiHec mould is a six cavity aluminum mould, then run the bullet metal at 725 degrees. Pre-heat the mould (I use a hot plate at just over medium) while my bullet metal is melting and reaching temperature.

Inclusions are almost always caused by dirty metal. Flux generously before you cast. Your pot may need cleaning, too.

FWIW
Dale53

[runfiverun]

wrinkly boolits with poor fill out.
could be copper in the mix, cold mold,or semi-cold mold and cold alloy temp.
you didn't mention your alloy but some tin might help if the above conditions are met and you still have poor fillout.
lets say your alloy temp is at 750* but your boolits are shiney and wrinkled.
mold too cold and/or oily
if your mold is warm [350+*] and you get incomplete fill out and shiney boolits.
alloy is too cold.
inclusions show up as little pockmarks on the face of the boolit and occur when you get oxides or gunk in the alloy..
they occur whether the boolits come out grey or frosted or shiney.
the mineral spirits could easily be leaving a film in the cavities.

[KYCaster]

Mineral spirits doesn't evaporate completely and leaves some residue. Use another solvent to clean the mold. MEC works well for me.

Jerry

[HeavyMetal]

If your using 95-5 lead free solder you have more than enough tin in your alloy, if your using 50-50 or less then you need to explore adding a little more depending on the % of tin in the solder your using.

Having said that I really believe you still have residue in the mold cavities!

My routine with a new mold: Non chlorinated brake cleaner, followed by a Q-Tip dipped in alcohol, followed by the boiling water nylon brush Dawn scrub down.

Run my pot at about 725 with pre heater hot plate set to Medium, one mold on the plate the other on the pot until alloy is at casting temp.

If the lead is good the boolits will be wrinkle free!