Difference in ingots.

[Charlie Two Tracks]

I melted some wheel weights last night and sorted out the very large truck weights from the regular car weights. I kept the temperature below 650 the whole time for both batches. (I'm trying to see if there is a difference in BHN between the two). Anyway. I went to the garage this moring to look at the ingots and the batch from the big weights were an off silver color. The smaller weights were the same color but on the bottom of the ingots there appears to be a crystal type look to the lead. I have searched "crystal" to no avail. Anybody know what makes that crystal type look to the bottom of the ingot?

[Bill*]

Does it look almost like the fresh galvanizing on a new garbage can, That is, flat designs on the surface like windows sometimes frost up, rather than 3D actual crystals? If so, I've seen it- It seems to me to be a product of a long cooling time. Like cooling the ingots on an insulated surface, or stacked on each other. I guess it could occur due to composition as well like what seems to be in your case

[Charlie Two Tracks]

It is the flat design. I poured the lead into small muffin tins that were outside on the dirt. The temperature outside was about 40 deg. Both batches were poured under the same circumstances and the crystal look didn't happen right away.

[lwknight]

If you are seeing a large crystal formation , you have very little antimony in the mix and they cooled fairly slowly. A 3% antimony mix will have more of a satin finish.

[zomby woof]

Same lead from what I remember. I'm guessing it was a cooling difference.

[Charlie Two Tracks]

That is exactly how they look. It propably doesn't make a difference but I was just looking for the "why". Something is going on with the lead.

[lwknight]

It had more to do with the cooling rate. Probably the second ingot was hotter in the pot to start with and heated up the mold more so that the total cooling time was longer and let the crystals grow larger.

[JJC]

Charlie Two Tracks I come up with a BHN difference of 1. Between the truck and car WW. I too keep them seperate but don't know it if it's worth it. Let us know what you find. John

[runfiverun]

in the above picture the one on the right is showing antimonial dendrites.
tin content and cooling rate will make a difference as will humidity.
this is why waterdropping and heat treating works.
tin allows the alloy to keep on breaking through the dendrites and explains why you get better fillout when addin tin to an alloy.

[Charlie Two Tracks]

Awesome runfiverun! That is what I was looking for. I just like to know why things happen. thanks.
JJC- I will post in a week or so. I want to see what they are after two weeks of being made. If it is only 1 BHN, I will mix them from now on.

[Cowboy T]

I typically see a BHN difference of maybe 1. My WW are generally BHN 11-12, so I just go ahead and mix them. As long as you're at the point of getting proper obturation with your load's pressure, you're fine. In the case of my .38 Spl's, therefore, I typically set my load pressure for BHN 12 and then go just the slightest bit higher, maybe 0.3 grain of powder, while of course staying under the max load (not a problem with WW's). Works great!

[Charlie Two Tracks]

After a week of letting the ingots sit, I've come to a conclusion....... I screwed up! I went out to the garage and tested them. One was 19.6 and the other was 16.5. What I did was....
I figured I would pour some small ingots so that they would fit in the press easier. I used a small muffin tin, about 1/3 the size of a regular one and didn't fill them all the way. They problem was, it was below freezing outside where I poured them. It must be like water quenching or something. Darn.

[runfiverun]

yep air cooling hardens lead too, bet they clink and tink with a merry sound though.
however, if they were poured at about the same temp, and had about the same cooling rate you know know that one has a bit more antimony in it.
i always just added about 25% big to regular then added 25% straps to that alloy and tin as needed for fill and made boolits for everything, waterdropping for rifle.
if i didn't have any big ones i didn't worry about it.
if i didn't have any stick-ons i didn't worry about that either.
and if they didn't need any tin i didn't worry about that either.

[Chapped Lips]

Same lead from what I remember. I'm guessing it was a cooling difference.

thanx,zomby woof........that pic just settled/explained what i've been seeing on the bottoms of my ingots after they've cooled......i have yet to smelt since the temps have dropped....i've got to winter smelt and compare the results to summer smelt.

charlie two tracks,cam on for posting this.....it's been drive'n me dinky dau....

[John Boy]

If you want to read a good article about crystalization formations of alloys, get the Lyman Cast Bullet Handbook, 4th Edition. Robert J Block. PhD, PE wrote an 18 page article, The Metallurgy of Cast Bullets that is A-Z in-depth and educational