Nasty alloy mix!

[JWFilips]

Well I did another casting session yesterday and this time 4 hours totally wasted!
I made up a batch of softer alloy ( BHN 10 /11 ) based on the calculator The good news (If they was any good news) was that the alloy came out as I had calculated the hardness.

It was based on a few 5 lb ingots of old plumbers lead (I got many years ago at a garage sale I used them for counter balance weights for years) Some newly smelted Sheet lead I purchased, Some pure lead (hornady swaged round balls) a bit of pure tin & some 60/40 solder off the coil ( this had some rosin in it as I found out when it went into the melt!) I figured that everything was clean ( and assumed the plumbers ingot were) Anyway after 4 hours of casting, remelting, fluxing the life out of it, I couldn't cast a bullet with out inclusions! My bottom pour pot plugged up about a dozen times or more which I had to clean out each time.

Now, I have had a few inclusions on on first few times I cast ( usually at the end when I let my pot get too low) & they were more like ash, which could be wiped with a fingernail .....However yesterdays were hard & sharp I just kept remelting and fluxing mixing & scraping the pot ( I spent more time doing this the actually casting! I went through a quart of sawdust)
Dropped very few I could trust to be good. I quit and figured that alloy will have to go to the smelting pot ( if it ever can be cleaned)

Ripped apart my casting pot today and scrubbed everything with a wire brush & steel wool. Had to get crud out of the spout & seating valve which wasn't easy. There was a yellow hard muck everywhere & it wasn't easy to get out.
It took me an hour or more to get the pot back to what it should be.
Nasty! I'm thinking that old plumbers solder was never smelted to be clean ...since it was to be used to seal sewer pipes What a waste of time & good alloys.

Do you guys think I could smelt the stuff back to usable state? I figuring if I smelt it and ladle pour into molds I may be able to salvage some of it.

[plainsman456]

Smelt it again and flux with a lot of sawdust.
Then do it again till clean.
You can do it.

[Charlie Two Tracks]

Once I get the pot of lead melted, I put a layer of sawdust on top and light it. Once it has burned, I stir it into the mix a few times to flux the lead and then leave it sitting on the top of the lead. I try not to let the pot get lower than 1/3 of a pot. I never put the sprue back into the pot while casting. If I put the sprue in as I cast, it seems to pull some of the burnt sawdust down to the bottom of the pot and can then mess up the spout. You can do it. It's just frustrating when things aren't working out.

[BruceB]

A large wooden dowel...say, about 1" diameter..... makes a highly-efficient way of getting carbon down into the melt. Not only is the dowel charring nicely 'way under the surface, but it also makes an effective SCRAPER for the sides and bottom of the pot at the same time. Try it; you'll probably like the way it works.

At 1"diameter, the dowel also lasts a long time.

[mefunkymxw]

do you have a lead thermometer??? how hot do you think your melt is getting, could you have some zinc in your alloy??? You might have to try some sulfer to get impurities out.

[JonB_in_Glencoe]

...a bit of pure tin & some 60/40 solder off the coil ( this had some rosin in it as I found out when it went into the melt!)

...My bottom pour pot plugged up about a dozen times or more which I had to clean out each time.

...Ripped apart my casting pot today and scrubbed everything with a wire brush & steel wool. Had to get crud out of the spout & seating valve which wasn't easy. There was a yellow hard muck everywhere & it wasn't easy to get out. It took me an hour or more to get the pot back to what it should be. Nasty!

Do you guys think I could smelt the stuff back to usable state? I figuring if I smelt it and ladle pour into molds I may be able to salvage some of it.

Last year, during a outdoors smelting session, using a stainless pot on a camp stove, I melted several rolls of solder. ONE OF THEM, AND ONLY ONE was acid core flux, I could smell right away, it wasn't rosin. as it cooked, it left a hard yellow crust in the pot...that wouldn't burn off, that wouldn't clean off, but I didn't put too much effort into that $1 pot, I just recycled it as stainless steel.

I suspect the problem isn't your alloy anymore, it was the crud in your pot...BUT, what I'd do anyway, once your casting pot is clean, is re-smelt your alloy outside in a throwaway stainless steel or cast iron pot...and never ever again smelt dirty alloys in your casting pot.
Good Luck,
Jon

[JWFilips]

do you have a lead thermometer??? how hot do you think your melt is getting, could you have some zinc in your alloy??? You might have to try some sulfer to get impurities out.

Yes I do ....The highest I ran it was about 725 I had no wheel wheel metal in this mix so I don't think it was zinc Now Since JonB metioned the solder core I'm wondering if that was the cause? Anyway it is now in a box scheduled to be re-smelted

[popper]

yellow hard muck Don't know what that stuff is but it sure messes up the spout. Haven't put anything in my pot but rotometal stuff, except I did sulfur it a couple times. Wonder if it is the sulfur byproducts in the plumbers lead? I used to use a wooden spoon to stir with but changed to SS when I was getting the charred wood in the CBs. Small hard black specks. Really hard to get that stuff off the bottom of the pot.