Surface voids - popped air bubbles

[Wilsknife]

On some otherwise perfect boolits, I'm finding surface voids that look like popped bubbles. Could this be from holding the mld too far from the pour spout? BTW, I'm casting straight Lino with a water quench. Could this affect it also?
:cbpour:
:bigsmyl2:

[GP100man]

The air should vent out the lines , is this a new mold ??? could be lube leachin out the pores of the metal , if it is run the mold thru a few heating cycles to purge the pores.

Also try different pouring techniques ??? swirling or even pressure casting .

[madsenshooter]

I found that a stream of molten alloy is going to oxidize as it passes through the air. Even lino bullets wind up looking bad with lots of oxides on the surface of the bullet. The answer for me was to switch to ladle casting. My older Lee pot had a longer spout that would allow me to pressure cast with some molds. I put a new pot on it, the spout is shorter and I can't do that anymore. Got tired of the drip anyway, my clothes and shoes were starting to look like I worked at a type foundry or something like that with all the little silver splatters on them.

[runfiverun]

if it's rough look at the mold again. closer this time.
now clean it.

[stubshaft]

Sounds like some type of contaminant in the mold.

[williamwaco]

Sounds like some type of contaminant in the mold.


DITTO.

Splashing the stream into the mold MAY cause wrinkles but I have never seen it cause voids.

Degrease the mold cavities at least three times with a degreasing agent and a toothbrush. I find that break cleaner does a good job but 409 and hot water does a better job ( for me ).

PS:
Water quenching Linotype is about like turning steel bullets on a lathe, and then sending them out for heat treating.

Last person I know that did that wound up breaking his sizing die.

[303Guy]

I had a casting with a slight surface depression which I didn't see straight from the mold. When I looked again I could have sworn that depression was bigger, Now it is bigger!

[stubshaft]

Water quenching Linotype is about like turning steel bullets on a lathe, and then sending them out for heat treating.

Last person I know that did that wound up breaking his sizing die.


I have sized tens of thousands of water quenched pure lino boolits without a hitch. I have been shooting them for over 30 years in sillywett competition and continue to do so.

I will concede that if you have an over size boolit and decide to take it down too much it may put a strain on you sizer, but the only sizing die I have ever broken was a .502" Lyman and that was with #2 alloy.

[Wilsknife]

My last casting session was done with a damp towel instead of water quenching.
The popped bubble look was non existant. This time the only issues were overheating and wrinkles.:lovebooli

:grin:

[geargnasher]

You finally cooked all the oil out of the mould.

Gear

[Jailer]

I was getting the same thing recently from a new mold. Turned out I had a small bit of lead stuck in one of the cavities causing the void.

[44man]

Straight lino is just too hard and expensive for most shooting.
It might be depleted of tin and the alloy is not bound together.
I ladle cast everything to keep air away from the pour. Cooling the stream to the mold does not make sense either.

[popper]

Are you sure is isn't just a 'fish-eye' from water drops(splash) getting into the mold when you water drop? Seems like it frys the calcium & stuff in the water to the mould and causes a little 'ring' spot on the CB.