A wrinkle in time

[Tatume]

Hello Folks,

Just as a topic of interest, here is a problem I’m trying to solve. My brother and I have nearly identical casting equipment: Lee 20-lb pots, similar molds, he uses a Lyman ladle and I use an RCBS ladle. We use the same alloy, from the same pile of ingots. We set the pots at the same thermostat setting. We cast at approximately the same cadence, and we each run two molds. We flux at the same times.

Casting shoulder to shoulder, outdoors, he gets wrinkled bullets and mine are perfect. We’ll be working for a while and I’ll say, here take mine, and we’ll swap molds. In short order I’ll be getting perfect bullets again and his will develop wrinkles. I’ve watched him diligently, and I can’t see that he is doing anything differently from me. It’s a mystery.

Sooner or later I’ll figure it out, and when I do I’ll post an update. Thanks for listening.

Take care, Tom

[alfloyd]

The pots may not be at the same tempature. I think that his pot is cooler than yours.

Just my 2 cents worth.

Lafaun

[montana_charlie]

Leave everythig the same, but change pots.
You cast from his, and let him start using yours.

I bet the wrinkles in his bullets will leave ... and migrate into yours.

CM

[gray wolf]

We cast at approximately the same cadence,
If your metal is at the exact Temp. Thermometer and not the dial on the pot, and his mold is clean,
You may be right on the cusp of good bullets or bad bullets and it could be your cadence that is making it work, approximately may not be close enough.
Sometimes what looks the same is not the same.
Next time you cast jump over to his pot and see what kind of bullets you get.
If they are not good make note to him what you had to do in order to make his set up work, perhaps you can ease him into it.
I am sure there will be a lot more opinions. I hope mine is of a little help.


Sam

[462]

I'm in agreement with Sam. "...approximately the same cadence" equals approximately the same mould temperature. Your brother's cadence is such that his mould does not maintain its optimum casting temperature.

[Harter66]

I'm for the pot dials. I'll bet his is just a little cooler add that to an 18-20 difference in casting rate and there you get it.

Another thought, is he in a corner or on the open airflow end that'd do it too .....................

[mold maker]

Even just a second or two of open time can make a world of diference, if your right on the edge. I'm betting on the pot adjustment. Thats where a thermometer makes all the equals really equal.

[Marlin Junky]

...he uses a lyman ladle and i use an rcbs ladle.

!!!!!

Mj

[noylj]

Why hasn't your brother turned up the temp on his pot?
Why continue to make bad bullets?

[Marlin Junky]

Why hasn't your brother turned up the temp on his pot?
Why continue to make bad bullets?

Or cast faster, or get a larger ladle?

Yes, there could be a difference in the output of the two furnaces which is something you can only check with a thermometer. Actually, I have two thermometers of different brands to check each other.

MJ

[williamwaco]

I'm in agreement with Sam. "...approximately the same cadence" equals approximately the same mould temperature. Your brother's cadence is such that his mould does not maintain its optimum casting temperature.




DITTO;

I bet you a peanut, he is casting slower than you.

[geargnasher]

Wrinkles not caused by oil in the mould cavities are caused by a mould that's too COLD.

Turning up the pot temperature won't really make that much difference anyway unless it was increased a hundred degrees or more.

You hand him a mould that's casting good, and in a few pours he loses it. That tells me the mould is cooling off. Get an analog wall clock with a second hand and time yourselves, cuz' he's slacking the pace.

By the way, why are you ladle-pouring out of a bottom pour? It takes a lot more talent/practice IMO to cast fast enough with a ladle to keep most moulds happy.

Gear

[357shooter]

Have your brother pour faster. Compare both pour techniques looking for differences as to how the alloy flows into the mould.