Casting session today turned sour

[high standard 40]

So today I decided to cast up a few RCBS 158s for my 357. I placed some ingots in the RCBS Pro-Melt and started heating that, then placed my mold on the hot plate. I had a few cast bullets of unknown origin that I had pulled from some ammo that a friend gave me. These were handloads, which of course I knew nothing about, so I had pulled them down. Best to be safe. The bullets appeared to be a similar alloy to what I intended to use today so I placed them in my pot to melt along with my ingots. As those unknown bullets melted (only about 12 of them) I expected to utilize the lube on them to help me flux the melt.That's when things went south fast. That lube was reduced to a thick black, oily sludge that would not burn. The more I tried to skim it off, the more it spread, The sides of the pot got covered as did my skimming spoon. The more I worked at it, the more it spread. I decided it best to cease trying and drain the pot so that I could properly clean everything. I had just cleaned my pot prior to this session. It is now a greasy mess. I could just see some of that grease finding it's way into my mold and screwing that up as well. I'm waiting on everything to cool right now so that I can start cleaning away this junk. God only knows that that lube was based on......Lesson learned.

[earlmck]

Wow! I do that all the time (remelt lubed boolits as a source of flux). Wonder what the heck you had there?

[salty dog]

That's weird. I've melted odd ball bullets, back stop pick ups, and other unknowns. Never had anything that would melt but not burn.

[Springfield]

Some sort of Moly lube?

[jeepyj]

I'd try to briefly take a torch to the top of the pot to see if you get it lit and burn it off. I'd be surprised if it wasn't petroleum based. Just my.02

[high standard 40]

My best guess is that it is some sort hi-temp synthetic. I was able to heat it enough to start it smoking a little, but it never ignited. It did adhere to the pot surfaces and caked onto it firmly. I had to scrape and scour it to remove it. Acetone removed some, but not that which was caked on. It's some nasty stuff for sure. I was able to get the pot back up and running and quickly cranked out about 100 bullets to see if there were any remaining negative effects. It looks good to go. I'm breaking for lunch and then will get serious turning out some bullets. Be careful of what you put in your pot.

[472x1B/A]

Some sort of Moly lube?

I'd bet the farm that was it. Had some do that to me last year, I just let it smoke off,( for a couple of days LOL ).

[country gent]

My guess is a form of synthetic grease moly mix. The synthetic greases and oils have a much higher break down temperature and molybdenum disulfide don't break down until around 5000*. It may even be a silicone or graphite. The hot flow properties you described point me to this.

[gwpercle]

All of that from the lubricant on just 12 boolits....what in the world could it have been.
I would love to know because I've melted a lot of range scrap in the past and would like to steer clear of that boolit lube !

I can tell you it's NOT Lithium-Beeswax lube.....I use that and have remelted many with no such instances as what happened to you.
Thanks for heads up,
Gary

[Minerat]

I've remelted some the Molly-bee lubed I use and haven't experienced this but I've not melted that many at one time.

[bangerjim]

Sorry to hear of your mess! As a rule, I never melt unknown “stuff” in my casting pot....only in a re-melting pot, either a 10# or 100# one. You never know what will be in/on those old unknown boolits!!!!! Keep the carp away from your casting pot.

good luck!

Banger

[high standard 40]

As a rule, I never melt unknown “stuff” in my casting pot....only in a re-melting pot, either a 10# or 100# one.

Banger

You can be sure that this will be my policy going forward. I never use my Pro-Melt for rendering my COWW. Didn't realize the risk with a pulled cast bullet. I do now.


I did run another 350 bullets with that pot today and had not further issues.

[lightman]

I never would have thought that would happen. I've remelted many a reject or left over bullet but they were all ones that I cast and lubed.

[bangerjim]

As long as you are re-melting boolits YOU CAST and COATED with stuff YOU know, you should not have any problems. It is those unknowns that can/will cause problems.

Just treat unknown boolits as you would other dirty scrap/COWW/SOWW and re-melt in your “other “ pot!

Problems solved!

Banger

[mold maker]

As long as you are re-melting boolits YOU CAST and COATED with stuff YOU know, you should not have any problems. It is those unknowns that can/will cause problems.

Just treat unknown boolits as you would other dirty scrap/COWW/SOWW and re-melt in your “other “ pot!

Problems solved!

Banger

That's a lesson I learned almost half a century ago. Free lead was scarce to me and every lead boolit or WW was to be salvaged. Mom gave me several canning lids that the glass broke out of. I didn't know any better and added them to my precious melt. They almost melted and ruined my stash.
From then on I don't add anything unknown, and I still have the lump of carp lead to remind me. I guess the second worse mess I had was Marvelux, and that was recommended by folks who supposedly knew casting. I was told it was a great improvement over the candle scraps I had used for a decade. It was over $6. a jar and I only tried to use about a teaspoon of it. What a mess. It set up like glass on my pot sides and tools.
When I started there was no internet or even readily available books. Most information was self-gained and hard-won. At least in this case, don't listen to folks who expound how good it was in the good ole days.

[Valley-Shooter]

I think you should have added some sawdust to the mess and skimmed it all off.
If in doubt, just flux it again, and again, and again.

[quilbilly]

That black stuff sounds like the tar remains from roofing lead used on a tar roof. I melted down that stuff only once and was glad I used an old pot.

[fatelk]

I guess the second worse mess I had was Marvelux, and that was recommended by folks who supposedly knew casting. I was told it was a great improvement over the candle scraps I had used for a decade. It was over $6. a jar and I only tried to use about a teaspoon of it. What a mess. It set up like glass on my pot sides and tools.

I'm glad I'm not the only one. I did the same thing, long ago. I spent good money on this supposedly wonderful flux called Marvelux. I tried and tried to use it, I really did. I tried following the instructions as best I could. After all, it's supposed to be great and the experts use it to great effect, right? So it must be something I'm doing wrong, right? 95% of it went into the trash after a while. It coated everything like glass, and when cooled would attract moisture and make everything rust. Terrible, terrible garbage.

[Gunslinger1911]

How could they ever sell that Marvelux stuff ? My story the same as others, nasty-glassy-**** that attracts moisture.
Nastiest stuff I ever tried !

[mold maker]

Another messy lesson I learned is to find and remove all those chips of clay pigeons from the range scrap before melting. Some of that stuff stinks and melts into a mush of pure unadelterated stickey excreatment. I don't know what they use to bond the "clay", but avoid melting it if at all possible.