Mold Only Half Filling out

[Mr. Kiss Kiss Bang Bang]

I am getting an issue where a mold will only fully fill out on one of its halves, on the other half I am getting rounded edges on the grooves and band. It’s weird because it only happens on one half of the mold, what would cause this? I was able to get a few to drop with good fill out but most of what I cast had to go back in the pot.

[sigep1764]

Cast faster and turn the temp up. Also, give the old a good scrubbing with dish soap. These three things are usually the root causes of rounded edges and not fully filled out boolits. Let us know how it turns out!

[FLINTNFIRE]

Sounds like your mold is to cold , pre warm it to temp , and how is the stream on your pour ?

[Conditor22]

It would help to know the make and size of the mold, some molds need different treatments
What alloy are you using?-----[harder alloys (more tin) melt &flow at a lower temperature.
How hot are you running the pot? --- [I like between 680° and 720° except for pure where I go 750°]
Are you bottom pouring or dipper pouring?
What pot you are using?

If the oil/problem is on 1 side the mold was probably shipped with that side down.

the first thing I do when you have mold fill out problems is re-scrub the mold cavities well with warm water, dish soap (acetone/brake cleaner/carb cleaner), and either a toothbrush or denture brush to get all the oils out of it.

It is best to get a hotplate (around $5 at a thrift store) with an old saw blade on top to prewarm you mold on (I've found that 400° is a good temperature)

Make sure the alloy is clean, flux the lead with sawdust then wax before casting (both will smoke, you should light the sawdust on fire) mix the flux well into the lead (I use a potato masher to get it to the bottom and a wire whisk to get it mixed in)

Make sure the sprue plate is hot or you will not get good fill out on the base of the boolit ( I keep a propane torch by my casting bench to warm up the spout or sprue plate when they get cool)

[Winger Ed.]

+1 to crank up the heat.

I'll start off as hot as I dare, then when I get 'frosted' boolits,
then turn pot heat down a bit until they shine like a diamond on a goat's ***.

[Mr. Kiss Kiss Bang Bang]

Thanks for all the ideas. I will clean the mold again and I think everyone is right it’s not up to temp. I think I was just thrown off because it was only not filling out well on one half of the mold. I have a hot plate that I just started using, I will make it hotter.

Pure lead
Bottom pour

[Bazoo]

If I'm casting and have problems I fill the hot cavities with lighter fluid. It will boil in the cavities but won't cool the mould like brake cleaner will.

Sounds like could be a venting issue. Also sounds like a too small a sprue puddle issue. I've one mould that's ornery unless I leave a rather large puddle that doesn't run off or into the adjacent cavity.

[Hanzy4200]

Hotter mold, faster flow stream, possibly hotter lead pot. Of course, a bit of tin in the pot.

[BK7saum]

Do you have a fan blowing from the side that isn't filling out? It could be cooling the mold half just enough to not get good fill out.

[Mr. Kiss Kiss Bang Bang]

Cleaned out the mold again very well. Slowed down my casting speed and more time on the hot plate. Casting good now. Thanks to everyone

[John Boy]

A mold must have a full cavity of melt in order to produce quality bullets ... pot melt and mold up to proper temperature, 5 second minimum pour, large sprue puddle and 10-15 seconds for the melt to harden