What is this?

[gnmontey]

I was draining my pot into ingots in order to switch alloys today. One batch of ingots for lack of a better word slumped when I dumped them. By slump I mean they didn't drop clean from the mold but rather came out soft, broke open or in half and showed a very course texture.

I should have taken a picture but didn't. This is a small fragment I found later.



Have never seen this before?

I re-melted them and it never occurred again.

Did I dump them too soon or something?

 

[yomomma]

More than likely dumped to soon, or ingot mold too hot I get a lot of that type of issue when i cast my pewter ingot

 

[leebuilder]

Yup don't know why, I was melting lead free solder into WW to make alloy. I think the melt was to cool. I put it back in it, it dissolved in no time once there was more heat.

 

[gnmontey]

I think the melt was to cool. I put it back in it, it dissolved in no time once there was more heat.

That may very well be what happened here. My PID was swinging all over the place (it looses it auto tune setting when powered down and I hadn't reset it) and the temp was rather low when I poured the ingots.

Strange phenomenon to say the least. It plopped out of the ingot mold like wet mud.

M

 

[vagrantviking]

First thought is that it was too hot.
Second is I hope you didn't get any zinc in the mix.

 

[gnmontey]

Second is I hope you didn't get any zinc in the mix.

Pot was full of a known alloy, I hadn't been mixing anything new in. I tested the final ingots with my hardness tester. The BNH is close to what I expected for the batch.

 

[leebuilder]

I am always learning, no patience and not waiting a bit for full heat were my best lesson so far.
Zinc contamination is like oatmeal once it dissolves it won't pour with out stringy/web glop, alloy with high copper will not glop up but will pour like zinc contamination does, the stringy/web effect
Be well

 

[jethunter]

If they break they are too hot, need more cooling before dropping.