Water quenching

[JRLesan]

Smelted down a half ton or so of wheel weights a couple of months ago and got around to casting a handful of projectiles this afternoon. Was always curious about the effects of water quenching so I dropped a dozen or so bullets directly into ice water from the mold. After shutting down, I tested quenched and unquenched slugs and was slightly surprised to find no difference in hardness - both were in the 9 BHN range on a cabinetree and an LBT tester. From the old days, I was under the impression that WW's contained arsenic which was the agent (element) that enabled lead alloys to harden with quenching. I made no attempt to separated clip on's from stick on's as I have a 2 lifetime supply of material from lead to lino. I was just curious to see if modern day WW's would quench harden. Input???

[Iron Mike Golf]

Retest those quenched boolits in a couple weeks. The hardening occurs over time.

[btroj]

Check them daily over a week or two. It will tell you something.

[DrCaveman]

Interesting, i would have figured they hardened more than that immediately upon water quenching. My fingernail tests from the day after water quenching sure show a greater hardness than air cooled from the same batch. But maybe my expectations are rigging the results

I understand like Iron Mike that it takes a week or two to gain full hardness. But still, the crystals formed by quick cooling via water quench should be harder than those formed by slow air cooling

Hey, wondering here... If you filed a flat spot onto the boolit for testing, maybe 1/8" from the edge of the boolit, you may have gotten deeper than the hardening went. That is to say, the hardening caused by water quenching is only on the surface, and testing below the surface could simply give you the same results as air cooling. This is also why people warn against sizing too long of a time after you have water quenched, as you may be removing the hardened portion

I dont really know my materials science, facts need checking

[dtknowles]

If your alloy only has a BHN of 9 air cooled then it is light on SB and will not water drop harden very much. That said, follow the advice above and check it again in a week and it should show some improvement. I think you might have got your Arsenic info from a Lyman manual. Lyman is a good reference but it is not completely the whole story. The antimony content is more important to quench harden eing than Arsenic. Sadly is seem you got a lame lot of wheel weights, mine air cooled go about 11 or 12 BHN.

Tim

[DrCaveman]

By the way JR, do you feel like parting with any of your 2 lifetime supply? If so, where are you located and if it is the pacNW, pm me please.

Anyway, there should have been some antimony and arsenic in there regardless of the mix between clip on and stick on. I get noticable increase in hardness from my 50/50 WW/pb mix when water dropped, measured about 15-18 bhn after a week maybe, and i only use the clip on WW. Straight clip on WW quenched for me gives about 22-28 bhn.

If there is ANY amount of antimony and arsenic in there (maybe only one of the two is needed, not sure) then in my small experience, it will harden when water dropped

[Magana559]

By any chance did you melt the stick on ww with the clip on?

[Garyshome]

I water quench everything. That way I can check for poor quality boolits as I cast.

[fatboy]

IMHO you should separate the stickons from the clipped weights, stickons are pure lead and will reduce you hardness.

[btroj]

What do they test today? Bet it is harder.

Ever wonder why many people size the same day if they water drop? Might be because the bullet hasn't hardened much yet and sizing is easier. What does that tell you?

[454PB]

Hey, wondering here... If you filed a flat spot onto the boolit for testing, maybe 1/8" from the edge of the boolit, you may have gotten deeper than the hardening went. That is to say, the hardening caused by water quenching is only on the surface, and testing below the surface could simply give you the same results as air cooling. This is also why people warn against sizing too long of a time after you have water quenched, as you may be removing the hardened portion

I dont really know my materials science, facts need checking

Not true, the hardening goes deeper than just the surface. I did an experiment on a quenched boolit, filed it to 1/3 of it's diameter, and it tested the same as the surface.

Full hardness is not seen until the quenched boolit is at least 30 days old. It begins increasing within hours, progresses rapidly, then begins to slow down. I have samples set aside that I've tested occasionally for the last several years.

[DrCaveman]

Good to know, 454pb. Thanks for the correction

What affect does the resting temperature have on rate of hardening? If I leave my boolits in the bucket of water for a week (with near-freezing overnight temps), should it harden more quickly?

[bangerjim]

They will get harder as time goes on. And Sb gives you the hardness.

I have some hardball-ish alloy that tests 15 normally. Water drop it and it WELL over 35 in a couple three days!

As said, segregate your COWW's from SOWW's. Stickers are pretty much almost pure lead. But you have the Cabine tester.....best there is.

bangerj

[btroj]

Sb does NOT have to be greater than 2% to get extra hardness from heat treating. I shot some heat treated to range scrap today that was tested at 1.7 % Sb and it heat treated to over 24 BHn.

[bangerjim]

btroj is correct.........many on here shoot an alloy of 96PB/2Sb/2Sn with great success. That is pretty close to what I use on almost all my plinking ammo and do not WD any of it. I go on air-cooled hardness and strive for 10-12Bhn (PC'd) and really do not pay much attention to the % Sb.

banger-j

[JRLesan]

Interesting replies for the most part. My quenched WW's peaked at 22 BHN after 54 hours. Will next try quenching lino just to see if it hardens appreciably.

[btroj]

Right around 11-12 BHn air cooled. Water dropping gives 22-24 but heat treat to 450 for an hour can push it higher. I need to see if I can go 475 without slumping.

[DrCaveman]

Im really starting to like the 50/50 ww/pb with a little bit of 50/50 solder thrown in, water dropped

It has made most of my rounds shoot better than ACWW from the same mould. The acww boolits were about 15-16 bhn, and the mix above got me 21-24 bhn or 27k-31kpsi

Im thinking of diluting the mixture with pure lead a bit more, til water drop gives 12-15 bhn after aging. The pure lead is cheap to me at the moment, and this water dropping seems a bit like alchemy

[btroj]

No alchemy at all.
Want to make the stuff even more useful over a range of pressures?
Heat treat for an hour then quench. By varying the heat treat temp you can alter and adjust the resulting hardness.

Yep, a single alloy can give a wide range of hardnesses. With some careful temp control and testing you can repeatably acheive a desired BHn.