Alloy issues?

[ryanmattes]

So I used the alloy calculator I found here, and mixed 1lb of 60/40 bar solder with 9lbs 12oz of stick-on WW, which should give me about 94% lead to 6% tin, with a BHN a little over 10.

Mixed it up and poured ingots, and I was surprised by the obvious crystallization in the ingots (see photo), but I don't really know what I'm doing, I'm just following a recipe, so maybe that's what it should look like.



But then I tried to cast with it. The first few bullets had a weird look to them, and when I knocked off a particularly long piece of sprue, it actually broke. It was brittle, and I could actually snap a long piece of sprue in half. The kicker was when a couple bullets dropped out and chipped. It seemed like there was no way that was a good lead for bullets; it seemed like they would shatter on impact.

So I threw it all back in the pot, poured about half the pot off into ingot molds, and refilled with WW lead. Then it started dropping what I expected, and I cast about 280 slugs that I still need to inspect, weigh and size.

So what happened? Is the crystallization expected with high tin content, or did I just add way too much tin? Why were they so brittle? Is 2% the ideal ratio for tin, and harder bullets require other metals to remain soft enough?

New to this, just need some explanation of what I'm observing.

[fredj338]

1/2# of tin to 10# of pure isnt that hard, what 20-1, if my math is right? That is what I cast my LHP with for magnums.

[ryanmattes]

1/2# of tin to 10# of pure isnt that hard, what 20-1, if my math is right? That is what I cast my LHP with for magnums.

Right, it didn't seem like it was a crazy alloy I was making, right around 20:1. Could I have had the pot too hot or too cold or something? Contaminants, maybe? The tin not mixed well with the lead? Or maybe the bar solder I got wasn't as advertised, and had either way more tin or something else in it?

I'll try to cast with those ingots again, to see if I get similar results. This time I'll take pictures if it does it again.

[charlie b]

Maybe you didn't flux it well enough.

[gwpercle]

Maybe you didn't flux it well enough.

My first thought also ... Did you flux and what did you flux with ?
I would have fluxed the pot twice ... with pencil sharpener (wood) shavings and beeswax first then a little Marvelux for good measure .
Gary

[ryanmattes]

I was using hardwood sawdust and candle wax, although I didn't flux heavily since I thought I was dealing with clean lead from ingots I cast, so I didn't need to.

Ill throw some of this in the pot this evening and flux it twice with sawdust and wax, and see if that makes a difference.

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[Mk42gunner]

Variation in the composition of your stick on wheelweights? I know they are supposed to be soft, and near pure lead, but the question is just how near they are to pure lead.

My guess is not very close.

Robert

[JonB_in_Glencoe]

Some stick-on WW have antimony.

[farmbif]

when I try to cast too hot I get bullets and ingots that look like your muffins, try turning the heat down a bit and see what it looks like, or use thermometer and keep pot of alloy at 720 degrees or so and see if they still have crystalized look when cooled. ive found change in outside temp has effect on lee pot thermostat . casting with dial set on 7 in summer time had to be turned down to about 5 yesterday when it was 47 degrees out I don't understand it but that's how it was for me

[ryanmattes]

when I try to cast too hot I get bullets and ingots that look like your muffins, try turning the heat down a bit and see what it looks like, or use thermometer and keep pot of alloy at 720 degrees or so and see if they still have crystalized look when cooled. ive found change in outside temp has effect on lee pot thermostat . casting with dial set on 7 in summer time had to be turned down to about 5 yesterday when it was 47 degrees out I don't understand it but that's how it was for me

We did just have a cold front. It was 90 or so for several days, and then 68 yesterday.

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[jsanch03]

What melting pot are you using? What you described Is what happens to my spure plate when I’ve been casting at a fast pace with a 6 cavity mold and the mold/spure plate get hot which means Its time to let it cool down. When the spure plate is too hot the spure becomes brittle if you do not give it ample time To cool/harden before breaking it apart. Check your pot temperature most people use a Lyman temp gauge in the pot.

[OS OK]

You have something really crazy going on there that I can't explain for sure...

Here's almost the same identical blending except that here is 5 1/2% tin, but it's close as close can be.

Here's what those ingots and cast should look like...cast @ 715ºƒ . . . .

[ryanmattes]

What melting pot are you using? What you described Is what happens to my spure plate when I’ve been casting at a fast pace with a 6 cavity mold and the mold/spure plate get hot which means Its time to let it cool down. When the spure plate is too hot the spure becomes brittle if you do not give it ample time To cool/harden before breaking it apart. Check your pot temperature most people use a Lyman temp gauge in the pot.

It's a lyman 10lb dipper pot. After looking at the lot I cast yesterday, I definitely had some temp problems. I've got a thermometer on the way, should be here in the next day or two.

I'll shoot them anyway, because why not. They're a little ugly, with some wrinkles and stuff, but on the pistol range they'll still be fun to shoot. I threw any that had problems in the base or bands back in with the ingots to remelt.

I also didn't have time tonight to try again, but I will this weekend, this time with a thermometer in the lead. I'll cast another few hundred and watch the mould temp more carefully.

And the end of the month is coming, so I should get another 20 or so lbs of WW from the tire shop down the street next week. Plenty of raw material to practice on in small batches.

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[Land Owner]

Constituents common in WW's include:
Lead 93.0 – 99.9 %
Antimony 0 – 6.0 %
Arsenic 0 – 0.5 %
Tin 0 – 0.5 %
Copper 0 – 0.1

No easy way to tell what is in any WW unless you know its pedigree, which they do not carry to the tire shop. BHN - IDK. Calculator probably predicts best. Ingots were and boolits are being cast TOO HOT.

...place the mold on a wet towel for 15-20 seconds after the surface has gone solid...

[JonB_in_Glencoe]

You have something really crazy going on there that I can't explain for sure...

Here's almost the same identical blending except that here is 5 1/2% tin, but it's close as close can be.

Here's what those ingots and cast should look like...cast @ 715ºƒ . . . .

I believe it's easily explained
Lead-tin-antimony, when cast hot will give a frosted/crystalized look.
Lead-tin will not.

OS OK, your image is exactly what my 20:1 casts like also.

[Rich/WIS]

Always thought that the solder rating was lead/tin, 60/40 was 60% lead and 40% tin. Have I been reading this wrong?

[Larry Gibson]

Always thought that the solder rating was lead/tin, 60/40 was 60% lead and 40% tin. Have I been reading this wrong?

That is correct, or at least it's what I've been told and believed for many years.

[Larry Gibson]

ryanmattes

I would say the WW (stick on) had some antimony in them. Did you actually smelt the stick ons or did you by them already smelted?

[ryanmattes]

ryanmattes

I would say the WW (stick on) had some antimony in them. Did you actually smelt the stick ons or did you by them already smelted?

I melted them all down myself, I got about 40lbs from two different tire shops. By themselves they made pretty good pistol boolits, but they were in the 7-8 BHN range by the pencil test.



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[OS OK]

I think, in this case we need a new term to define this casters level of 'FROSTY' ...

If I cast too hot and overheat the mould or if I cast too fast and overheat the mould I get what I've always called 'FROSTY' ...

This is frosty...



This is not frosty...



If I hadn't read the type of lead he used, I would have sworn that he had some high antimonial type lead from the picture and the description of it's brittleness.

Posts like this one with the question of . . . . "What did I do?" . . . . without more details, without pictures of everything involved including where the dial was set & the color of the melt in the pot are hard to answer, especially when they have no idea of the temperature.
His pot should'a looked like burnt soft lead, 950ºƒ or higher...dark purplish to blackened surface, if he had watched it closer, it would'a gone through a rainbow of coloring before he got where he is now.