Lead-free solders for adding 0.5% or 1% tin to WW

[Forgetful]

I've been using 6" of 1/8" solder (Sn/Sb, 95/5) for every 10 lbs of WW, and it's been going well. I get nice fillout and they're shiny. I'm concerned about adding too much tin because these have to be able to take 50,000psi and tin can cause age softening, so I'm starting to consider other "impurities" that contribute hardening/strengthening.

So I found some other lead-free solders I'm considering using. One is Tin/Copper/Silver (95/4.5/0.5) that I think I will try (1oz to 10lbs WW). I don't know if the copper and silver content will have any effect, but I found it less expensive than the Sn/Sb stuff I had. I'm also going to add some rotometals super-hard to the mix, 1/2lb for every 10 lbs of WW which should add another 1% Sb (to ensure at least 3% Sb in my alloy).

So, I'm curious what the copper and silver would do to the alloy. This blend (if the WW are 2% Sb) would be:

Pb 96.095%
Sb 3.314%
Sn 0.562%
Cu 0.027%
Ag 0.003%

[fastfire]

Copper= good
Silver= will kill werewolves

[Tatume]

I would ignore the silver and copper. Tin and antimony are the important alloy components in bullet metal. Personally I'm partial to Sn2/Sb3/Pb95.

[Tatume]

BTW, buying lead-free solder is an expensive way to get tin. You can pick up some good deals on solder or pewter (almost pure tin) in the "Swapping and Selling" forum here. Just keep your eyes open.

[bangerjim]

I use 2% Sn in all my boolits. Never any problems.

Don't overthink this very simple process. Add some Sn, cast them, and go shooting!

bangerjim

[cbrick]

snip - - - I'm concerned about adding too much tin because these have to be able to take 50,000psi and tin can cause age softening,

Any "age softening" that may take place will be very slow. The biggest concern using tin is to not have a higher tin percentage than antimony. If you quench or HT your alloy higher percentages of tin will limit the amount of strengthening (Hardness) that can be achieved but at the percentages your talking about even this is pretty minor. It would be a good alloy adding up to 1 - 1.5% Sn.

I did an experiment on convection oven heat treating and age softening using clip-on WW +3% Sn. RCBS 35 200 bullets where heat treated to 30 BHN, packed in a box, labeled and set under the bench for 10 years and yes, they age softened . . . they were 27 BHN. Ok, it wasn't an intentional test, I put them away and found them 10 years later. With all that I had heard about age softening I thought they would be putty but they were still 27 BHN.

Rick

[Echo]

By adding 6" of 1/8" lead-free solder to 10 lbs of alloy, you are adding a skosh over 1/4 oz of Sn to 160 ounces of alloy...

[Forgetful]

By adding 6" of 1/8" lead-free solder to 10 lbs of alloy, you are adding a skosh over 1/4 oz of Sn to 160 ounces of alloy...

oops I had 6" for every 5 lbs (2ft per 20 lbs). My bad.

[Echo]

Ok - that's 1/4 oz per every 80 ounces, or a ratio of 1/320 - about .3% added...
Hardly worth the effort, but if it works, it works...

[Tatume]

Pb 96.095%
Sb 3.314%
Sn 0.562%
Cu 0.027%
Ag 0.003%


I would ignore the silver and copper. Tin and antimony are the important alloy components in bullet metal. Personally I'm partial to Sn2/Sb3/Pb95.

Echo is correct. To add 0.562% tin to 20 pounds of alloy you need about 1.8 ounces of tin. I don't know how long a one pound roll of solder is, but unroll it and cut it into nine equal length pieces to get 1.8 ounces each.

Also, in my opinion, this is not enough tin. To reach 2%, which I use, you would need 0.4 pounds, or almost half a roll of lead free solder. This is why I suggested you find less expensive sources of tin.

Take care, Tom

[Forgetful]

Just to clarify, I said I have been using 95/5 and it's been working well. I'm going to be using some 95/4.5/0.5 (Sn/Cu/Ag) and stated 1oz to 10lbs WW, and presume the WW are 2% Sb and 0% Sn. I put my values in my spreadsheet, and reported my expected percentages.

Naturally there will be some tin in the WW already, I just don't know how much and all I needed to succeed in these .511's was ensuring at least 0.5% tin is added.

Edit:
320oz WW (98/2) + 16oz SuperHard (70/30) + 2oz solder (95/5) = 96.1% Pb, 3.34% Sb, 0.56% Sn.

If the WW are closer to 0.5% Sn and 3% Sb as I expect, the yield becomes 94.7% Pb, 4.29% Sb, 1.04% Sn.

The point was to have guaranteed minimums.

[cbrick]

Naturally there will be some tin in the WW already, I just don't know how much

If the WW are closer to 0.5% Sn and 3% Sb as I expect,

I told you in another thread, expect clip-on WW to contain 0.5% Sn. I didn't pick this number out of my hat, it is an average of several XrF tests run on WW. You will be closer to actual clip-on WW if you reduce your assumed Sb to 2% instead of the 3%.

Rick

[cbrick]

Ok, I see you edited the post and that you added Super Hard for the Sb. Still, use 2% Sb as an average in clip-on WW.

Rick

[Forgetful]

I appreciate the advice. 2% Sb and 0.5% Sn WW, and adding the solder and superhard like I said in my OP, will give me 3.34% Sb and 1.04% Sn. I was wanting to achieve a minimum 3% Sb (I read 2% alone won't achieve 30 BHN) and 1% Sn.

[cbrick]

3% Sb and that much or less Sn is a good alloy. I normally equal 2% Sb with 2% Sn for my long range handgun match loads.

As one that has done a lot of BHN testing shooting groups to 200 meters I can tell you that 30 BHN is not needed and can open up groups. Here is a link to an article I wrote on HT boolit alloy and describing this testing. You may find this info interesting reading.

http://www.lasc.us/HeatTreat.htm

Rick

Edit to add: Yes, you can achieve 30 BHN with 2% Sb clip-on WW with 2% Sn added. See the same article.

[Forgetful]

The alloys with 2 and 4% Sb (antimony) harden comparatively slowly, and the alloy containing 6% Sb appears to undergo optimum hardening.
Quenching of castings from arsenical lead-antimony alloys offers an attractive alternative method of effecting improvements in strength. The alloy containing 2% Sb clearly does not respond sufficiently to be considered as a possible alternative. The 4% Sb alloy, however, attains a hardness of 18 HV after 30 min, and the alloys that contain 6, 8, and 10% Sb could be handled almost immediately.


Due to this, I felt 2% is too low. I intend to push a 675gr .511 past 2500fps, mold maker recommended 30 BHN. I will be heat treating these at 480F. I thought 2% would be too low because it could be 1.8% or maybe 2.2%, so I wanted to make sure I had at least 3%.



Wheel weight alloy with an average composition of: 1/2% tin, 3-4% antimony, 1/4% arsenic and 951/4% lead can be heat treated to well over 30 BHN but it's a rare bullet that needs to be this hard unless your shooting very top end 454 Casull loads at 65,000 PSI.


I'm shooting 50 BMG loads at a maximum velocity.

Another edit: I don't have a source for adding Arsenic, but WW will have an unknown As content. 303Guy on this thread (http://castboolits.gunloads.com/showthread.php?186516-Best-way-to-add-Arsenic-to-alloy-Without-wheel-weights) mentioned sulfur or copper. This is what got me interested in adding copper-bearing lead-free solder since I've only been able to source Tin from these solders available to me. Garage sales for pewter are a rare find, and when I find pewter in resale shops they're very pricey, like $50 for a single stein. So I figure having a little copper in there could have a hardness synergy with the trace arsenic, much like Guar gum and Xanthum gum increase viscosity more so than either can independently by weight.

[cbrick]

The quote from the heat treat article is a quote from the metals industry, more accurately from a non-ferrous company that supplies the lead alloy to automotive battery mfg's to make the plates. In that environment they were looking for eliminating as much as practical the aging time, they wanted to pour the plates and as soon as cool put them into production. That's why they mention up to 10% Sb as ideal but settled on 4% as practical. As boolit casters we can achieve the strength (hardness) we need with the patience of the aging/time curve. Part of the HT testing I did was with low SB alloy and I achieved the same BHN as my normal WW alloy but in 3 weeks instead of three days.

Arsenic (As) is the most commonly used grain refiner in the metals industry, I would assume because of cost and ease of blending into lead alloys. There are several other grain refiners used such as sulfur. From the results of the XrF testing done on this site it appears sulfur is removed fairly easily by fluxing.

I've never had any problem getting stick-on WW (2% Sb) with 2-3% Sn added to achieve 30 BHN with the use of a convection oven and carefully adjusting the temp to barely below alloy slump with test boolits prior to HT'ing the good boolits.

Your results could well depend on the boolit fit in the chamber/throat/bore. What mold do you have? Have you done a pound cast for proper measurements?

Now I know why they call you Forgetful, each time your ready to pull the trigger you have forgotten what your shoulder felt like the last time. :mrgreen:

I for one would be very interested in your posting the results of your shooting. Sounds fascinating.

Rick

[Forgetful]

I haven't cast the chamber yet, but I do have a pound of cerrosafe intended for that purpose. The main reason I haven't is because it was difficult enough getting a mold and sizing die for the '50. I'm hoping it just works out for me. If the bore is actually .511 then I won't size them, since the lee sizing die is giving me .510 and the mold is dropping at .511. If it's .512" then I'm a little screwed but I can't imagine that being the case because it shoots .510 accurately -- Hornady 750gr A-Max I measured .510 and that's also whats on the box. In this caliber, there already are tight tolerances.

I started this thread with the question of the copper content in my alloy, sourced from solder. I'm now looking at Babbitt alloys to try, so I can guarantee the arsenic content and maybe push that closer to 0.5%. Really though, I think I'm set, guaranteeing >2% Sb and >1% Sn with trace Arsenic, Copper and Silver. Trying hard not to be anal because the WW is largely an unknown blend... all I know for sure is that it's 99% clip-on WW. There was one brand of stick-on that tested hard (using angle cutters) so I included those, and there were a handful of clip-on that tested soft (which surprised me) so I excluded those.

In my mind I'm ballparking these values even though I weighed every ingot to add and the tin too. I think the solder was about 20.5 grains per inch, so I measured enough feet of it and weighed it, and added another half-inch to get my calculated value. I consider this a ballpark because I'm just aiming for guaranteed minimums and I'm more used to using exact mols with 5 significant digits. Deep down I know if I added another lb of lead it to a 35lb mix, it isn't going to change the alloy very much but I wanted to nail down an expected average to use for when I mix up another batch and expect to use the same load data and DOPE.

And my shoulder is the least of my worries. The Barrett's muzzle takes all that down to almost nothing. I have more to worry for Retinal Detachment!

[Tatume]

Garage sales for pewter are a rare find, and when I find pewter in resale shops they're very pricey, like $50 for a single stein.

As I said earlier, the Swapping and Selling forum on this list serve is an economical source of lead/tin solder and pure tin in the form of remelted pewter. Pewter typically sells for $11 per pound, and is usually available. You do not need to haunt yard sales.

[cbrick]

I haven't cast the chamber yet, but I do have a pound of cerrosafe intended for that purpose. The main reason I haven't is because it was difficult enough getting a mold and sizing die for the '50. I'm hoping it just works out for me. If the bore is actually .511 then I won't size them, since the lee sizing die is giving me .510 and the mold is dropping at .511. If it's .512" then I'm a little screwed but I can't imagine that being the case because it shoots .510 accurately -- Hornady 750gr A-Max I measured .510 and that's also whats on the box. In this caliber, there already are tight tolerances.

You can't compare apples and oranges. There is no correlation between any rifle shooting jacketed .001" under groove diameter and cast doing it. Ideally your cast boolit will be .001"-.002" over groove diameter. Trying to shoot cast under groove diameter will cause all manor of headaches such as gas blow by which leads to gas cutting the driving bands (leading) and blowing the lube out ahead of the boolit (more leading), striping while engaging the rifling etc. Even if you use 30 BHN boolits that's quite soft as compared to the 100+ BHN of jacketed. Getting accurate bore measurements will tell you a great deal about what direction to head in.

It might well be worth your time to start out at a more sedate velocity around 2000 fps and work up from there. It's a far easier goal to achieve and as you work up you should be able to see where/if trouble begins.

Rick

[Forgetful]

As I said earlier, the Swapping and Selling forum on this list serve is an economical source of lead/tin solder and pure tin in the form of remelted pewter. Pewter typically sells for $11 per pound, and is usually available. You do not need to haunt yard sales.

I'd go for that if shipping were cheaper. I should ask the scrapyards about their pewter and other tin alloys they might have. I'm careful about shipping stuff from across the border, due to weight. Rotometals sent me 25lbs of superhard but it cost $50 in shipping, but that stuff will go a long way before I want more. And I need to prove to myself I need to add it, so it's part of my testing. $11 per pound will easily become $33 per pound with shipping, and thats about the price of a pound of lead-free solder already. I have a friend near Detroit I could ship to and then visit for pickup and drag it back.. Currently, the extra cost for the tin is a convenience factor because I wanted to get this rolling.

[Forgetful]

... Trying to shoot cast under groove diameter will cause all manor of headaches such as gas blow by which leads to gas cutting the driving bands (leading) and blowing the lube out ahead of the boolit (more leading), striping while engaging the rifling etc.

At least it's gas-checked. That has to help, right?


Getting accurate bore measurements will tell you a great deal about what direction to head in.

Agreed. I'll cast it tonight or tomorrow and get a set of measurements. It's a Barrett M99, and I haven't seen anyone post measurements of theirs for comparison. In fact, trying to research reloading specific to the 50BMG hasn't been fruitful.


It might well be worth your time to start out at a more sedate velocity around 2000 fps and work up from there. It's a far easier goal to achieve and as you work up you should be able to see where/if trouble begins.

Absolutely. I wouldn't dare putting 225gr of charge for a first load! I'll probably never have that much. I want to get groups for sets of loads and step it up until I find a charge that starts getting me close to 2500fps.. Then work on getting the spacing right so the boolit is barely touching the rifling and THEN I can see which alloy performs better. Then stick with that alloy recipe and dial the charge in for the tightest groups and see what I can come up with.

[Tatume]

I'd go for that if shipping were cheaper. I should ask the scrapyards about their pewter and other tin alloys they might have. I'm careful about shipping stuff from across the border, due to weight. Rotometals sent me 25lbs of superhard but it cost $50 in shipping, but that stuff will go a long way before I want more. And I need to prove to myself I need to add it, so it's part of my testing. $11 per pound will easily become $33 per pound with shipping, and thats about the price of a pound of lead-free solder already. I have a friend near Detroit I could ship to and then visit for pickup and drag it back.. Currently, the extra cost for the tin is a convenience factor because I wanted to get this rolling.

Shipping to anywhere in the U.S. is typically included in the purchase price, at $11 per pound. In any case, up to about 20 pounds can be shipped for $5.80.

[cbrick]

Shipping to anywhere in the U.S. is typically included in the purchase price, at $11 per pound. In any case, up to about 20 pounds can be shipped for $5.80.

Tatume, pay attention, he said he's in Canada.

Rick

[Tatume]

I have a friend near Detroit I could ship to and then visit for pickup and drag it back.

This just in:

http://castboolits.gunloads.com/showthread.php?252382-Pewter

[Forgetful]

So I called around, talked to a few scrapyards. They buy tin. They won't sell tin. Jerks.

[bangerjim]

So I called around, talked to a few scrapyards. They buy tin. They won't sell tin. Jerks.

Too bad you live in a "commi" area! There are many of them around the country. My yards around me are more than happy to sell me anything....... from Pb, Sn, & their alloys to brass ( bar/sheets/pipe/tubing/1st fired casings). And they do the X-ray testing for free.

I just hauled 280# of Sn home!

There ARE many advantages to living in a large metro area.......the RIGHT one.

Good luck finding what you need.

banger

[Forgetful]

yeah I'm a little jealous of your 280#!