Hot Oatmeal?

[ColColt]

This has happened before so, it's not the first time. Casting the other day I started out once the alloy was up to speed added a big spoonful of sawdust, let brown and fluxed. About an hour later I stirred again sans the sawdust and stuff came to the top that looked like grey oatmeal. I dipped it out thinking it was just trash/junk. What was it if that wasn't the case?

[Drdarrin]

ah, I'm thinking it's most likely your tin. flux that stuff back into your melt. Your bullets will thank you for it.

[Charlie U.]

Zinc in your lead maybe?
What is the source of your lead......wheel weights? If so, there is the possibility you had some zinc in there.

[ColColt]

It wouldn't go back into the mix, that's why I skimmed it off. However, I saved it just in case. It was a mix of 1:20. I got the lead from Kathie about six months or so back.

[ColColt]

Alright, here's what I skimmed off. Pictures tell it all. Door #1 says tin. Door #2 says zinc. Is there a door#3?

http://i180.photobucket.com/albums/x220/ColColt/_1DF3170a_zpse81a0498.jpg (http://s180.photobucket.com/user/ColColt/media/_1DF3170a_zpse81a0498.jpg.html)

[Horseman1]

Could you put a little chunk in some hcl (muriatic acid) and see if you get hydrogen gas (zinc does this)? Maybe folks with more experience have other ways to tell. I keep hcl around for getting rid of galvanizing on steel before welding or cleaning up rusted steel.

[Walter Laich]

Zinc--

[scottfire1957]

I have had lead look like that when the propane pressure dropped and the pot cooled a bit.

[Ed_Shot]

I believe that if it was zinc you would have had oatmeal immediately when your alloy went liquid. I think the important question is how were your boolits casting during this session. Were you pleased with the boolits and were they dropping at the normal weight?

[ColColt]

This pot is thermostatically controlled-no propane. The bullets looked great and later when they cooled most all weighed 534-535.5 gr. I would have thought I'd get that sort of thing floating from the get go but it didn't happen. It was only later when I decided to stir again that it surfaced.

[dkf]

I get that sometimes. Matter of fact I have some floating on my pot now since I have been heating up the pot and shutting it off 5 times within the last week. I am lapping a mold and needed to check it several times after lapping. Fluxing with paraffin usually mixes it back in though on one occasion the paraffin did not work but candle wax did. There is next to no chance the alloy in mine has any zinc in it because it is indoor range scrap that I melted myself in a thermostatically controlled pot.(with some Tin based babbit thrown in) So I figure the oatmeal floater is Tin which I sure don't want to get rid of.

[nighthunter]

It looks to me to be dirt. I've had a few similar experiences and think it could be from dirt that has built up on the sides of the pot under the alloy level suddenly coming loose and to the top of the pot. Zinc would make a slushy mess of the entire contents of the pot. If it were mine I'd drop it back into the pot and work it with a piece of hardwood. It doesn't take much alloy to hold a fair bit of dirt. I don't believe it to be tin as I don't believe it to be an easy process to remove the tin from the alloy. Just reaching casting temp isn't enough of the process.

Nighthunter

[ColColt]

Speaking of dirt, I took a look at my ladle and it was dirty all the way around.