Pretty colors ,but is this Zinc contamination ?.

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  • Last Post 25 June 2013
adrians posted this 04 August 2012

Hello again ,

i got this little dipping pot at a yard sale and knowing that it had been wiped out after it's previous owner had done his last cast i like an idiot that i am put 10 lbs of known alloy in the pot and fired it up ,,,,,,, this is what i got .:X :X :X .

I think I'm going to dump the melt and start from scratch, but how do i get my pot zinc free (assuming this is indicative of zinc contamination).

please help a hopeless sole fix this,,

sorry for this oversize pic , i need to figure out how to re-size using photobucket..

i thank you much. 

 

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Duane Mellenbruch posted this 04 August 2012

TURN DOWN THE HEAT !  

I think you got it quite a bit too hot when you cranked it up.  Did you get a thermometer yet?

Duane

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linoww posted this 04 August 2012

my lead from nuclear shielding bricks does this at all temperatures.i was told it was calcium.

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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TRKakaCatWhisperer posted this 04 August 2012

looks like several trace elements in there.

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CB posted this 04 August 2012

I'd flux it, skim off the top and cast. If the CBs fill out fine, no problem.........Dan

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adrians posted this 04 August 2012

well fellas i turned down the heat for one thing and then fluxed the all get out of it ,about six times and the color went away with the “skin” but there is still an unfamiliar skin on the melt, though not as colorful but still not “normal” .

The bullets are o.k i suppose ,not the best this mold (311291) has given me but they will probably be alright for my plinking purposes.

I don't know what the other fella was cooking in the pot but it sure wasn't cool  :cusout:

thanks gents..

Adrian.:D

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Duane Mellenbruch posted this 05 August 2012

adrians wrote: and then fluxed the all get out of it ,about six times and the color went away with the “skin” but there is still an unfamiliar skin on the melt, though not as colorful but still not “normal” . What are you using for flux?  Were you careful to scrape the sides and bottom of the pot and stir so the dirt or oxides would rise to the surface? A small metal spoon on a wooden handle makes a nice skimming tool. The bullets are o.k i suppose ,not the best this mold (311291) has given me but they will probably be alright for my plinking purposes.What is the nature of the defects in the bullet?  Embedded debris?  Wrinkles?  Voids?  Incomplete bands or rounded edges.  Are they casting larger, smaller, heavier or lighter than normal?  How is the color and sheen on the casting?  Was the melt hot enough or perhaps a bit cool.    Was the mold up to casting temperature?   Duane

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adrians posted this 05 August 2012

Duane ,the bullets are pitted as i hope you can see ,,

i flux with sawdust and run the temp with the dial at about 10 o-clock on the lyman dipper pot.

These are the worst looking bullets i have ever made  :cusout:    

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Duane Mellenbruch posted this 05 August 2012

Really odd appearance of the surface of the bullets.  Generally the castings are well filled except for the last band and the gas check shank.  Perhaps you are running out of alloy in the ladle or not leaving a sprue on the top of the sprue plate?  Or the sprue froze before you were done filling the mold.  Increased temp a bit might help.   Those thermostat settings are just a reference and do not really tell anything about actual temp, just where to set it after you get the temp figured out.  Does the sprue freeze quick or stay liquid a few seconds? 

Did you use the casting ladle when you were stirring, fluxing and skimming the melt?  Possible contamination, but I am not so sure it is zinc.  I have mostly avoided that problem by temp control when smelting and have not tried  casting bullets once I thought zinc had contaminated the melt.  Anyone else have an idea?

Good photos by the way. Thanks.   Duane

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linoww posted this 05 August 2012

Dan Willems wrote: I'd flux it, skim off the top and cast. If the CBs fill out fine, no problem.........Dan

my pure lead doesn't react to this but i sure wish it did.it casts good bullets its just a pain to keep skimming and cleaning the ladle.

George

"if it was easy we'd let women do it" don't tell my wife I said that!

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Maven posted this 05 August 2012

The late Ken Mollohan (Molly) had this to say about using sawdust as flux:  “I wouldn't recommend wood dust though.  Not only is it very smoky and aromatic, but i know of at least one professional caster who blames it for almost putting him out of business because he couldn't cast good enough bullets after trying sawdust."  (TFS 218-10)

Btw, the rest of Ken's article,"Techinical Ramblings:  More on Fluxes,” TFS 218 is definitely worth reading.

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1kshooter posted this 31 May 2013

try a little ivory soap as flux or candle wax...I had way better results with them and I had bullets that looked like yours after I tried to flux with saw dust!

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jhalcott posted this 31 May 2013

I always thought sawdust was iffy as a fluxing agent. In the steel mill they used a certain wood stick always from the same kind of tree to flux and stir the pot when casting bearings. When the stick “charred” the melt was ready to pour! The melt was about 750 to 800 degrees. I used a laser thermometer to test it a couple times, and the old guy was correct on the temps. I've had results similar to those when casting with “mystery metal” but the bullets were still good enough for plinking and ground hogs at out to 100 yards in a 30-30 Contender.

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Jeff Michel posted this 31 May 2013

Dump it and cut your losses. Clean your pot real well. I'm not an expert, but I've seen the same in my pot. It will contaminate everything you put in it. If it's impossible to flux,skim,lumpy, or produces a rough surfaces on you bullets as your picture suggests. I wasted a couple days messing with it trying to cast it and dilute it out, nothing worked. If it isn't zinc or calcium, it's something every bit as nasty. Good luck

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delmarskid1 posted this 01 June 2013

Sell the junk to a scrap yard. One that is far from me. Better yet give it to some guy who makes sinkers. I'm glad it was only 10 pounds. I'd empty the pot and give it a good cleaning with steel wool or sandpaper if it's bad enough. It's a good idea to do this once in a while anyway.  Those little pits will hold liquid alox or some such very well I think. You mat have broken new ground and turned our world upside down!

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shastaboat posted this 01 June 2013

Dump it and clean the pot.

Because I said so!

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Pigslayer posted this 01 June 2013

I've had zinc contamination but as I remember it was like a sticky gooey mess on top of the pot. Threw it all out & cleaned the pot. Never saw anything like yours though. wonder what the half life is?

If someone else had of done to me what I did to myself . . . I'd have killed him. Humility is an asset. Heh - heh.

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Pigslayer posted this 01 June 2013

I've had zinc contamination but as I remember it was like a sticky gooey mess on top of the pot. Threw it all out & cleaned the pot. Never saw anything like yours though. wonder what the half life is?

If someone else had of done to me what I did to myself . . . I'd have killed him. Humility is an asset. Heh - heh.

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Pigslayer posted this 01 June 2013

I've had zinc contamination but as I remember it was like a sticky gooey mess on top of the pot. Threw it all out & cleaned the pot. Never saw anything like yours though. wonder what the half life is?

If someone else had of done to me what I did to myself . . . I'd have killed him. Humility is an asset. Heh - heh.

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cityboy posted this 01 June 2013

1kshooter is right; try using ivory soap. Slice off thin slivers so it melts easily. It smokes little, has a good smell and is cheap.

Jim

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Vassal posted this 01 June 2013

I have a small batch of pure (or near) lead that does similiar to that. I can't remember if I tried to cast with it yet or not. makes nifty looking ingots though,,,

Maybe there's a homosexual bullet caster who'll pay top dollar.

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