Why?

[bgokk]

I cast these TL .41's in 2009 and they have been sitting in a peanut butter jar ever since.
118684The pic (cell phone) isn't sharp but the thing I ask why about shows very well. Why are some shinny and others dark. They came from the same pot of COWW, same casting session. About 1/5th of the jar are dark. The dark ones are very uniform in color.

[triggerhappy243]

residue from inside the jar.

[country gent]

May be a reaction to the plastic and or heat sunlight. The plastic may have given off fumes that afected some close to it

[bgokk]

residue from inside the jar. The jar was washed with soap and hot water even the smell was gone.

May be a reaction to the plastic and or heat sunlight. The plastic may have given off fumes that afected some close to it The dark boolits were scattered through out not in just 1 or 2 areas of the jar. I don't recall any 2 actually touching.

[wbrco]

Single, double or multiple cavity mold?

[bgokk]

Single, double or multiple cavity mold? Double!

[btroj]

Simple oxidation, no big deal

[RED333]

Simple oxidation, no big deal
Yep, happens sometimes, my question, Why have you waited SO long to shoot them?:Fire:

[bgokk]

Simple oxidation, no big deal I agree not a big deal, but why just a few in the container, all from the same casting session and same alloy. The only oxidation I have ever seen on lead was white, sort of powdery looking and would rub off on a cloth. This is very uniform and does not look like a layer of oxidation looks more like the boolit was dyed.

[BNE]

Since the jar was clean and then closed, all the boolits saw essentially the same condition for the time they were in the jar. I suspect that something was done diferently when they were cast. Just guessing but were:
- Some water dropped and others not?
- the timing of how long the boolits were in the mould prior to dropping. ie did you hold some, longer than others? (Do the sprue cuts look the same?)
- What was your mould temp consistent?

Hope this helps steer you closer to what caused the difference.

[triggerhappy243]

I could see pure lead darkening like that. lead with more tin and antimony? I dont know. I have not cast hard cast very long but have casted pure quite a while.

[bgokk]

Since the jar was clean and then closed, all the boolits saw essentially the same condition for the time they were in the jar. I suspect that something was done diferently when they were cast. Just guessing but were:
- Some water dropped and others not?
- the timing of how long the boolits were in the mould prior to dropping. ie did you hold some, longer than others? (Do the sprue cuts look the same?)
- What was your mould temp consistent?

All air cooled, sprue cuts much the same, these were some of my first attempts at casting there are some wrinkles and some had a slight radius on the base. These were before my thermometer so temp could have varied.

Hope this helps steer you closer to what caused the difference.

RED--- They were undersized for my RBH and I just never got around to melting them down.

[dtknowles]

I cast these TL .41's in 2009 and they have been sitting in a peanut butter jar ever since.
118684The pic (cell phone) isn't sharp but the thing I ask why about shows very well. Why are some shinny and others dark. They came from the same pot of COWW, same casting session. About 1/5th of the jar are dark. The dark ones are very uniform in color.

It was something you did you are not telling us. Maybe you don't know but everything has a reason.

Tim

[shoot-n-lead]

The dark one's may be ripe.

[blikseme300]

Jedi boolits. Some went over to the dark side. [smilie=l:

[JeffinNZ]

The dark one's may be ripe.

LOL. Gold!

[RED333]

RED--- They were undersized for my RBH and I just never got around to melting them down.

You are forgiven. :drinks:

[303Guy]

I'd say it would be differences of temperature, either mold or alloy or both. Do you know of a metallurgist or chemist you could take them to? I have some castings that have turned grey like that, not as dark as the picture shows but that could be the photo. Old sinkers turn grey. But why only some?

[1johnlb]

A little more time and air and all of them would turn dark.

[44man]

Alloy change in the pot as you use lead! Flux more.
Spray the boolits to be stored with something like Barricade to keep air off. Works great with pure lead balls.

[dondiego]

Were you using a mold release? The first boolits out of the mold might be darker or have more of some chemical on them.........

[bgokk]

Maybe you don't know but everything has a reason.Tim
You got that right!!!!:confused:

[Gtek]

My guess would be casting temp swings of alloy/mold creating different surface on boolit. Frosty vs. slick, surface area with different structure for oxygen interaction.

[bgokk]

Were you using a mold release? The first boolits out of the mold might be darker or have more of some chemical on them.........
No mold release, just a clean mold.

[bgokk]

My guess would be casting temp swings of alloy/mold creating different surface on boolit. Frosty vs. slick, surface area with different structure for oxygen interaction.
That is probably true about the temp swings.