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Full.Lead.Taco
I came into possession of a decent amount of soft lead (dental xray lead) and was looking at various options of hardening it up. I was wondering if buying and mixing in some monotype/foundry type lead would be a good way to harden up my alloys. On ebay it looks like foundry/monotype lead costs around $2 per lb. Rotometals has their super hard alloy, but it costs quite a bit more than this. Any advice on hardening my alloys without spending a ton of money?
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georgehajduk
You may want to double check on the hardness of that lead. I too have a BIG stash of it myself, used to work on xray equipment for 15 years, did a lot of de-installations that’s how I got mine. Turns out on a average I was getting around 12 to 13 BHN. If I water quenched it came close to 18 BHN. I was playing around with it a year or so ago a was able to cast some nice pistol and rifle bullets but didn’t get to shoot them. I do recall I needed to add Tin to the mix to get better fill out. There’s a good article at LASC website on the super hard metal and they have a few recipes to try out.
Maineguide
steveleonard
How hard do you want them? Adding antimony will harden them up. Tin will reduce the surface tension of the alloy. This helps with mold fill out and tin will also add both a little hardness and toughen up the alloy.
You could scrounge up some clip on wheel weights (COWW) and mix them 50/50 for about 8-10 BHN.
(COWW= about 3% antimony, 0.5% tin and 96.5% lead)You can mix with magnum shot BB’s for their antimony. Then add enough tin for good mold fill out for 8-10 BHN.
(magnum shot= about 3-3.5% antimony and 97% lead)Heat treating by either water dropping into cold water while casting or oven heat treating at say 450*F and quickly quenching in cold water will harden up any alloys that contain antimony. A 50/50 mix of COWW and your presumably pure dental x-ray lead could heat treat to 17-18 BHN or more. Wait for a week or more to use after casting and heat treating to maximize the effects.
To test for the presence of antimony in your x-ray lead, heat treat a piece and compare it to your other alloy after a week.
dannyhunley
Here’s a simple rule of thumb that I use when adding alloy to PURE lead to create a determined hardness (not heat treated) …
You want to end up with 2 – 3% tin. You need the tin to allow good fill out in the cavity and help the sharp edges come out sharp (as opposed to rounded). I prefer 3% for most of my NOE molds. Too much tin just wastes an expensive alloying element. Then, determine what hardness (in BHN) you need for the application. Now, allow 8 points for the lead, 1 point for the 3% tin and then add 1% antimony for each additional point of hardness in BHN. For example, if you want a BHN of 16, you will need 7 percent antimony in the final mix — 8+1+7=16. So, your finished alloy will be 90/3/7 (90% led, 3% tin and 7% antimony). Remember that when you are adding any kind of -type, you are adding lead in addition to the tin and antimony.
I hope this helps.
Full.Lead.Taco
I was lucky enough to get a bunch (1200#) of old printer’s type. I use that. It is a random mix of mono- and foundry-type. I mix it with 3.5 parts lead to one part -type. I end up with an alloy that is about 92/4/4 (confirmed via XrF). It’s a little rich in tin but it allows me to make bullet alloy using only lead and -type. I use it in handgun loads.
garynordgran
Here is the link to Rotometals. They have bullet casting alloys. If you look at the bottom of the page they have a formula on what metals do to harden your alloy.
stilly
https://www.youtube.com/watch?v=klHk_5vhaTg
You might want to have a look at this video too.
Mike B.
I tend to add recently recovered lead shot from the range to my pure lead to create something close to wheelweights to start with…
Most dedicated diehard trap shooters will not shoot reclaimed lead as it’s deformities etc… apparently tends to leave holes in their patterns… according to those shooters…
However it contains between 2 – 3% antimony … which will tend to harden the alloy mix…
So … As someone previously said How hard do you want to make the alloy?
If you don’t have the Quick Design program, & want some intel on predicting the alloy mix then post by PM what you might have and the amounts… I can run the alloy calc portion of the program, & PM the results … & reply to you via that communication method… unfortunately NOE PM’s do not currently allow attachments
It is what it is…
Also you may want to look around at what is historically still local at the older tire shops that you can still get access to as technically waste products…. such as the older used wheelweights themselves… as an alloy component… Just don’t mix in zinc…
OBTW zinc melts at ~ 700 degrees F and lead melts at something like 625 degrees F, with tin melting at something like 425 degrees F … So keep your melts around 650 degrees in a separate lead pot specially setup for mixing up alloys for ingots…
That’s from memory so don’t Quote me…
The periodical tables on the internet can give you the exact temperature figures in both F & C …
If you can’t read the markings stamped on the wheelweights… Fe by the way is iron, & besides floating up on the melted lead … will not melt with any possibly heat that a lead pot can normally generate as a heat source supply…
Pure lead can also be obtained from old houses that tended to have pure lead pipes … & fittings … when the pipes are changed out… for newer & saver iron plumbing…
If you haven’t figured it out by now I am among other things also a lead scrounger… who collects & recycles range lead … Isn’t recycling what it is all about now days …
Besides it helps to keep the EPA from circling the range … if your range allows such recovery … as part of its normal reclamation process … ALSO be sure to get formal permission to recover the range lead or lead shot from the officials who run the range so that your behind is technically covered & they can record the recovery and recycling of said lead for their EPA records…
Recycling & document it for their records… Just keep in mind the safety precautions for lead, & don’t eat or drink while recovering said range lead … Plus wash up your hands & face properly afterwards … Also wearing a mask will also help in the long run also from breathing in lead dust…
According to the EPA Its not hazardous waste until it is moved from where it finally landed and was left lying around for an extended time period. I forget the EPA time period from the lead management books… but it is a rather long time period from its initial removal from its resting place for recycling & recovery…
So start the process to recycle the lead as soon as you can to remove that EPA designation … as once the recycling process has begun the hazardous waste specter designation goes away according to the EPA regulations that I down loaded circa 2016 …
Quick design has an alloy calculator as one of its options… with that option you can add a plethora of alloys together & get the prediction of what your end alloy will be…
Physical Properties of Common Bullet Alloys
Elements in the Alloy Lead Tin Antimony Spec. Gr. BHN
Wheel Weights: 95.5% 0.5% 4.0% 11.0096 12
Lyman #2 Alloy: 90.0% 5.0% 5.0% 10.6829 15
Linotype: 86.0% 3.0% 11.0% 10.3830 19
Monotype: 73.0% 9.5% 17.5% 9.6700 26
Roto Metals Hardball: (Terracorp) 92.0% 2.0% 6.0% 10.7789 16
Roto Metals Super Hard: 70.0% 0.0% 30.0% 9.3917 37
Pure Lead 100.0% — —- 11.3450 5
Dental X-Ray Lead 97.5% 1.5% 1.5% 11.1379 10.4
50-50 Solder 50.0% 50.0% ……. 8.9111 14
Lead Shot 95.0% …… 5.0% 11.2145 10.13Range Lead (Composite Total) 95.26% 3.74% 1.0% 11.0428 10.6
10 : 1 Lead – Tin Alloy: 90.9% 9.1% 0% 10.8083 11.5
9.09% Tin
10 Lead + 1 Tin = 11 units of Alloy
9 .1 Lead + 0.9 Tin = 10 units of Alloy16 : 1 Lead – Tin Alloy: 94.1% 5.9% 0% 10.9918 10.53
5.88% Tin
16 Lead + 1 Tin = 17 units of Alloy
9.4 Lead + 0.6 Tin = 10 units of Alloy1/20 Tin/Lead Alloy 95.0% 5.0% 0% 11.0434 10.15
5.00% Tin
19 Lead + 1 Tin = 20 units of Alloy
9.5 Lead + 0.5 Tin = 10 units of Alloy20 : 1 Lead Tin Alloy: 95.2% 4.8 % 0 % 11.0574 10.03
4.76% Tin
20 Lead + 1 Tin = 21 units of Alloy
10 Lead + 0.5 Tin = 10.5 units of Alloy30 : 1 Lead Tin Alloy: 96.8% 3.2% 0% 11.1485 9.11
3.226% Tin
30 Lead + 1 Tin = 31 units of Alloy
9.7 Lead + 0.3 Tin = 10 units of AlloyTake Care, & Stay Safe…
georgehajduk
steveleonard
dannyhunley
garynordgran
stilly
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