Crowd funding a clip-on wheel weight AES analysis

[BHuij]

A few years ago, I did some experiments with heat treating clip-on wheel weight alloy bullets at different temperatures, then quenching and tracking BHN over a few weeks to see where it stabilized. You can read about why my experiments ended up not being very useful here.

I'm back at the casting pot doing a much more exhaustive study of various factors that affect BHN of heat treated ternary lead alloys. As I've been conducting experiments, logging data, and looking at results, it occurred to me that it's very frustrating not knowing the actual composition of my alloy. I've been melting, fluxing, and casting bullets from COWWs sourced from the same place in Utah for years, and have 200+ lbs of COWW ingots. So far I've just kind of assumed 95% lead, 2.5% antimony, 0.5% tin, and the balance trace amounts of other stuff like zinc, copper, arsenic, etc.

I realize there's probably some variance in content between clip-on wheel weights from different manufacturers, etc., but taking kind of an "average" ingot by randomly selecting a number of mine, melting them together, fluxing thoroughly, and casting up some samples to have tested via atomic emission spectroscopy would, I think, take a lot of the mystery and speculation out of what I'm trying to do.

I reached out to a lab and got a quote to have a sample tested and an actual composition report generated, for $174.

Is there any interest in crowd funding this, so everyone can benefit from having a good idea of what's probably in their COWW alloy? It's not a huge sum of money, but it's more than I want to spend alone on a pet project. If we could find even 10 or 15 people who are interested to know the pb/sn/sb/other makeup of COWW alloy with a level of certainty I haven't found elsewhere, the price per person quickly becomes negligible, and the one-time expenditure gives us data that will be useful indefinitely.

Even if this ends up not panning out right now, I'm continuing with my COWW heat treating experiments, and will post a comprehensive write-up in the coming couple of months or so, when all of my experimentation has wrapped up, and I've had time to analyze the data and form conclusions.

 

[Spindrift]

This could maybe be a cheaper alternative

https://www.rotometals.com/metals-analysis-test-xrf-service-test-only-not-the-machine/

 

[BHuij]

This could maybe be a cheaper alternative

https://www.rotometals.com/metals-analysis-test-xrf-service-test-only-not-the-machine/

Great resource - I don't know much beyond a Google search about the relative pros and cons of XRF vs AES, but if XRF can get me about a decimal point of accuracy and precision in my final composition percentages, that's plenty good enough for me.

 

[popper]

heat treating clip-on wheel weight alloy Don't see any real purpose that would justify the expense.
1) big variance in composition of COWW.
2) Big variance in HTing.
3) Composition doesn't really relate to anything - not to BHN or malleability, other 'physical' characteristics that WE can apply. Sure real values of strength of metal can be found but how to apply them? Kinda like the Lee chart? We can measure but what is the result effect?

 

[BHuij]

1) Yes, important to note that any results I end up getting can't necessarily be generalized to anyone else's COWW alloy. Which probably kills my case for crowd funding, but if I decide to go for it, I will at least have a decent idea of what my stockpile of lead is made of
2) This is actually what I'm experimenting on right now, with some fairly promising results so far.
3) Interesting point, I'm not sure I understand or agree. It's generally accepted that COWW alloy in its base state has a lower BHN than Linotype, because of Linotype's higher antimony/tin content. Wouldn't that mean pretty clearly that alloy composition absolutely DOES relate to BHN?

I think the frustration here for me stems mostly from the fact that I'm trying to be as scientific as possible about everything I do with cast bullets, and not knowing what my alloy actually is seems to spit in the face of that, even if I can replicate results and find patterns without that particular piece of information.

 

[Rick]

What your trying to do has been done some years back on the boolits site. Many people from many areas of the country sent in WW samples to two different XrF test facilities, one in Arkansas and the other on the east coast. That thread should still be there I would think though I don't remember the thread name or who started it. The final results were at least to me kinda surprising in that there was far less variation in test samples from across the country than I assumed. I also don't remember the exact numbers but since that test I make the assumption that CWW is 2% antimony and between .5 and 1% Sn, about .25% As. The remainder Pb, other trace components weren't enough to matter or bother with.

I also did extensive heat treat testing of CWW several years back. Here's some of the results.

Heat Treating Lead/Antimony/Arsenic Alloys

Hope this helps ya out.

 

[popper]

Yield and tensile strength, ductility, Poisson's ratio, density, modulus of elasticity, coefficient of thermal expansion, specific heat etc.
Yrs ago I investigated a company that did this kind of testing with a computerized machine. We still don't know exactly how to use the numbers. I've got some strength curves someplace on this computer someplace. They are for pure, not COWW.

 

[Bliksem]

My opinion, you get what you paid for, is that too many people worry too much about their alloy and they neglect other pieces of the reloading puzzle that have greater effect on accurate reloads. I was once in this group. I'm not implying that the OP is not paying close attention to the whole reloading process but becoming fixated on a single step or requirement of the whole process will in most instances have a less than desirable outcome.

Philosophical & tired brain warning ahead, been awake more than 36 hours after solving a mini disaster at work.

The concept of using hardness testers to determine alloy suitability for cast bullet ammunition is silly as this is equivalent to using a pressure gauge on a pressure vessel to determine it's volume.

I found, as others have before me, that accurate cast bullet loads are a combination of many things coming together properly. Alloy is but a small part of the recipe. Worrying about the alloy distracts people from concentrating on the whole process. Hence the Art & Science of the hobby/obsession.

Yes, I have a good idea what my alloys are and I mix them in large batches and then do load work-up and once a sweet spot is found I load sufficient rounds in a batch for storing. The known-good loads are used for hunting so there are no surprises after many hours of driving and long hikes. The satisfaction of the successful hunt using hand crafted ammunition is priceless - that's why I do it! Buying factory ammo is way too easy.

 

[Ian]

Count me out. It's far more fun to take a big batch of ww-ish alloy and learn how to make it shoot well in a variety of guns and chamberings than to work the other end trying to narrow down and put in a box the secrets to accuracy.

I went through exhaustive analytical work with the bullet lube thing. Have lab reports on certain waxes via friends that would have cost me thousands otherwise. Degreed tribologists helped too. Have literally hundreds of containers of regeant and pharmaceutical grade ingredients, some of which you can't just go out and buy in less than boxcar quantities. In the end I settled on thermoset paint, safe in the knowledge that if even I didn't fully succeed in my mission, I left no stone unturned and have a vastly improved understanding of how a lubricated cast bullet works. So go for it, but let it lead you where it takes you and pay attention to all the data, not just the data you are looking for.

 

[Joshua]

An old man once said "Grasshopper, too much Science, or too much Art, makes for a poor bullet caster"

"But Master, I don't understand." Said the Apprentice.

"Seek balance in all things." The Master paused, obviously deciding about whether to say the next thing. And then said "Also, you should avoid closets in Bangkok, they can be very dangerous." And then he walked away.

 

[Ian]

I know this man. He also observed that "Man who stand on toilet, high on pot".

 

[BHuij]

What your trying to do has been done some years back on the boolits site. Many people from many areas of the country sent in WW samples to two different XrF test facilities, one in Arkansas and the other on the east coast. That thread should still be there I would think though I don't remember the thread name or who started it. The final results were at least to me kinda surprising in that there was far less variation in test samples from across the country than I assumed. I also don't remember the exact numbers but since that test I make the assumption that CWW is 2% antimony and between .5 and 1% Sn, about .25% As. The remainder Pb, other trace components weren't enough to matter or bother with.

I also did extensive heat treat testing of CWW several years back. Here's some of the results.

Heat Treating Lead/Antimony/Arsenic Alloys

Hope this helps ya out.

Huh, so that's your article. That's the one I read back in 2018 that made me get interested, and want to do some of my own testing.

2% antimony, 0.5% tin, some fraction of a percent of arsenic, and the rest being lead with some unimportant trace amounts of copper, zinc, etc. that don't really have an effect is exactly what I've been assuming. I will probably get some XRF analysis done at some point through Rotometals, it's reasonably priced enough. Hopefully if nothing else, I can confirm those %s aren't too far off.

Near as I can tell, the final BHN is a function of how hot the bullet is at the time of quenching, and how quickly it drops below a certain threshold temperature to freeze the alloy. Wasn't sure if colder water would have a significant effect on that or not, but it does seem like bullet mass and surface area might, since I could easily get my .225" cast bullets up above 30 BHN, but the same treatment for 9mm bullets landed me in the mid 20s. Right now the tests I'm doing are on oven heat, water temp, and bullet surface-area-to-mass ratio.

I've been using a non-convection toaster oven for a couple of years, and it gives me good results when powder coating (and so far repeatable results when heat treating too), but it does seem like a potential source of confounded data when I'm trying to be very scientific about these tests, so I just bought a convection oven to do all my heat treating and powder coating going forward.

Thanks all for the input.

 

[popper]

If you want hard, 2-4% Sb and 2% Cu, WD immediately into ice water that IS cold (added salt helps), leave there for 10 min. They shoot fine and are upwards of 36 BHN. Pushed a PB one (145gr) to 2100 in 300 BO and got almost MOA @ 100. AR500 plate only way to 'capture' them, as dust, as I never found one. Cuts right through 12ga steel wire. Don't have a BHN tester but they dented a superhard ingot. I did this for grins and giggles, no practical use for me.

 

[Joshua]

My opinion is that the more you travel down this road the less utility will be realized.

That being said. If you are having fun who am I to discourage you.

The hardness difference you are seeing between 22 and 9mm has to do with how quickly the mass quenches. When water is used as a quenching medium steam production slows the quench time. The steam bubbles surround the part being submerged and insulates the part from the cold water. A wetting agent can help alleviate this problem.

Here is an article on a quench that is used to harden low carbon steels. It is made with a mixture of water/salt/soap/& a wetting agent(suficant).

Link:

Robb Gunter

Have fun!
Josh

 

[BHuij]

Popper, out of curiosity, how are you adding your copper? I assume it's not as simple as just tossing some wire into the pot? My pot at least doesn't get up to 2000 F, I believe

 

[popper]

Use garden CuSo4 copper sulfate (Zep root killer), pour measured amount on top of melt. Wait till it turns white, the stir the dickens out of it and CAREFULLY remove the greyish powder on top (Zn or Sn sulfate). Do not inhale. It replaces Zn or Sn in the alloy, Zn is much cheaper. Flux with wax and stir to clean all the junk out. Let alloy 'bake' for 1/2 hr before pouring. Size a day at most later. As will sped up hardening. Salt in the ice water will allow temp to get below 32F, dawn blue will work as sufficant = surface tension reducer. I don't use either, too lazy. An OP used a copper wire welder to zap the melt and add the Cu. IIRC he almost broke his press trying to size them, not WD. IIRC annealed Cu is BHN 36.

 

[Dimner]

I have been in the market for lead recently. Nearly depleted my own lead supply. I realized that around my parts, clip on wheel weights are not easily found. They can be found. But if I wanted large quantities, it would take far more leg work than I was willing.

So I have switched to more reliable sources of lead to get the alloy I am looking for. Using the alloy calculator spreadsheet that is well known, I have found that the cheapest, yet most uniform, alloy is going to be indoor range lead in addition to rotometal's super hard.

This will be adding $0.10 per lb using superhard rather than buying a large supply of salvaged Linotype. But that 10 cents per pound really gets me a much more 'known' alloy composition than I would get with salvaged linotype. I plan on making up about 300 or more lbs of this alloy. It will be the equivalent of 50/50 range + cww. Just without the arsenic. Then as needed I will add magnum chilled shot to smaller quantities if I need to play around with heat treating to obtain very hard bullets. The other benefit of this alloy is that it's easily repeatable with similar composition results. I plan on making a stockpile to last me a decade or three, but if I find I need more in 5 years, it will be easy to make again.

So long story long..... Clip on wheel weight testing might not be relevant as they are harder and harder to find. Building a base stock of alloy in large quantities and in a known composition may be a better use of time and treasure.

 

[Rick]

Dimner, with your added WW and the Super Hard you wouldn't have much need of the magnum shot. If your keeping your antimony% low the only downside would be a longer time to reach final hardness but they will still get there. If your going to heat treat arsenic is not mandatory, look at it as frosting on the cake, without it you still have a fine cake.

 

[JonB]

I have been in the market for lead recently. Nearly depleted my own lead supply. I realized that around my parts, clip on wheel weights are not easily found. They can be found. But if I wanted large quantities, it would take far more leg work than I was willing.

SNIP>>>

a couple weeks ago, my buddy who is a "Metal Recycler Hobbiest" and all around scrounger, said he just got in a couple 55 gal drums of WW. I asked if this was vintage stuff from a Auto salvage yard or new stuff collected at a tire dealer? He has lots of sources for the Metals he hauls away from businesses. He tells me it's newly collected and judging from a previous batch he got, he figures this batch is about 30% Lead WW to 70% non-lead WW. We didn't get to a price per lb, I just turned it down, for fear of being WAY TOO MUCH work...he understood.

 

[Dimner]

Dimner, with your added WW and the Super Hard you wouldn't have much need of the magnum shot. If your keeping your antimony% low the only downside would be a longer time to reach final hardness but they will still get there. If your going to heat treat arsenic is not mandatory, look at it as frosting on the cake, without it you still have a fine cake.

Right on the money Rick. I had come to this conclusion when I was running the numbers for my alloy. I had ran calculations with and without arsenic. Decided it was more prudent and cost effective to ditch the arsenic. Heat treating currently represents about 10% or less of what I do casting wise. So unless a situation comes up where I am in a big hurry, heat treat without arsenic will do just fine.

To throw another wrench in it. I might play around with using sulfur as a grain refiner in the future. Not because I need a grain refiner... but because I'm a sucker for learning. Probably a good project for next winter when range time is limited.