Attempting to make Lyman#2...questions

[Tinker]

Attempting to make Lyman #2 alloy for the first time. I'm trying to do this with known ingredients because I do not have a hardness tester to check my work. Got some questions after first attempt.

The known components are:
Pure sheet lead
Superhard alloy (70% lead/ 30% antimony pre-mix)
Solder (that is 95% pure tin)

Steps I took:
Smelted lead into small ingots.
Then remelted those with proper proportions of Superhard and tin solder.

Note here and questions.....noticed when I smelted the pure lead and poured into ingot trays that the pure lead solidified almost instantly. I could flip the ingot mold over in less than 30 seconds. These ingots were shiny and solid.

After alloying that pure lead with the Superhard and tin solder I'd have to wait 2 minutes before the ingots were solidified enough to knock out of the ingot trays. And when I did knock these alloyed ingots they were frosty and would often break when they fell out. Is that normal for Lyman #2 alloy?

I also noticed during the alloying smelt that a good bit of grey powdery looking material would float on top of the new alloy. Is that normal? I think I read once that the grey stuff is antimony leaving the alloy. Is there a way to prevent this? Thanks.

 

[35 Whelen]

Head on over to the Lead and Lead Alloys section of the Cast Boolit forum where you'll find an Excel based lead alloy calculator as well as ways to test hardness of alloys.

I've been binge smelting myself lately and discovered what you did; lead hardens fairly quick, but metals such as linotype and especially printers or block type takes MUCH longer! Frosty is pretty much normal and I've noticed my pure lead is much more shiny than the harder alloys.

To keep your elements mixed together in your smelting, you need to flux them. You use just about any wax based product, but I normally use bits of bullet lubricant and also keep an old candle on the bench from which I break off chunks for fluxing. Toss a chunk of whatever you choose in the pot, light it to burn off the smoke and stir like the dickens. I usually stir with a sliver of pine which of course burns. The resultant charcoal from the burned wood also aids in fluxing. After fluxing, scrape off the trash and pour in to ingots.
Good luck!
35W

 

[41 Mag]

The calculator mentioned above is pretty good on blending up alloys. It might not get you down to the last hundredth of a percent, but it will get you plenty close for casting good bullets with a repeatable hardness.

As mentioned when blending or smelting you will need to flux your alloy. Some use paraffin based stuff like candles and such, but most use fine sawdust and simply sprinkle it over the top of the alloy and give it time to charcoal. Once it has turned black stir it into the alloy over and over for around 3-4 minutes or so and the carbon will attract and reblend the tin and antimony back into the lead. It will also keep the tin from oxidizing out of the alloy as well.

I use both methods myself. I flux up to three times with sawdust while in my big pot. Then I will flux once with paraffin before I pour the ingots. The later may or may not help, but my ingots are nice and shiny when done, and I do not end up with much if any trash in my casting pot.

When I melt down the ingots in my casting pot I use the paraffin to flux once more before pouring just to get what little bit of just there might be in there out. I usually end up with only about a teaspoon worth or less of anything when done.

Go over to the link posted above and do a bit of reading as well as over to the LASC site here as well. You should be able to find plenty on smelting up the alloy and what to do with it while your working it as well as afterwords.

 

[Tinker]

Thanks for the replies. Cast Boolits is where I got the ratio for using Superhard and solder. I also think I fluxed correctly using wax. I will try the sawdust thing too, just for giggles. I just had concerns about losing what I think might be antimony.

One more thing. I just bought a brand new 20lb Lee bottom pour pot. I've yet to use it. This thing is purty and I don't want to dirty it up smelting. Currently using my old method of an old stainless steel cook pot on a butane burner to melt out wheel weight clips, etc.. The plan is to only use "ready to cast", relatively clean alloys in the new Lee pot.

 

[Nwflycaster]

Most sheet lead is cast and rolled to the QQ-L-201f grade B spec, but be careful because there is a fare amount of 6% antimony sheet lead out there as well.

Also, you mentioned your solder is 95% tin. The balance could be either antimony again or copper and possibly silver, you wouldn't want to be adding any copper content to the alloy. If it came from a spool it should say on the label or if from a bar it should be stamped. If no markings, I would assume the balance to be antimony.

A mixture of tin-antimony-lead will lower the melting temps a bit and also the antimony will give you the frost on the surface you spoke of. But a 5-5-90 alloy shouldn't break when dumping the bars, it's not that hard of an alloy. I would check your math. I don't know what size bars your casting but 2 minutes to set up sounds like a lot.
We cast that alloy into either 5#, 8# or 40# bars, and even the 40 pounders don't take 2 minutes to solidify.

As far as the mixing goes before you cast into bars, all you really need to do is stir in a rolling motion top to bottom for 20 - 30 seconds to have a homogenous mixture. It helps to have a "T" shaped stirrer and stir every 20 to 30 minutes. The grey powdery substance in normal, it's just the oxides (dross). Even virgin metals alloyed into alloy will generate about a half percent of oxides.

 

[41 Mag]

One more thing. I just bought a brand new 20lb Lee bottom pour pot. I've yet to use it. This thing is purty and I don't want to dirty it up smelting.

Your on the right track there for sure. Nothing but good clean alloy in the pouring pot.

 

[Tinker]

Nwflycaster,

The tin solder I'm using is 5% silver. Figured that would float out of the alloy. Was not aware of the impurity of sheet lead. Thought that was pure.

Another thing I picked up at Cast Boolits was checking hardness with artist pencils. An HB pencil is supposed to indicate 15 BH. This alloy checks harder than that. The HB left a streak, not a scratch. The additional antimony that might be in the sheet lead may have skewed this batch.

41mag,

That is what I was thinking. Thanks for the reassurance.