Some odd solders found

[RogerDat]

regular 1# thin (1/4 - 3/8 inch or so) flat bar solder. One type labeled 2-5/8% and the other type labeled No 20.

I figured the 20# at $20 was worth it for solder even if not especially rich solder. But was wondering if anyone was familiar with those labels and had an idea of what they were used for.
I was sort of thinking leaded body work. Low tin for filling and if the No 20 is 20% Sn then that might have been used to tin the body panel before filling. But that is all just a SWAG. Been around 25+ years since I did a small amount of lead body work and don't recall the solders used.

Any ideas on if those numbers are tin percentages and/or what that solder was used for?
I can mix 2 5/8 Sn at 50/50 with WW's for a nice pistol or mild rifle round. Or use as is for HBWC rounds. That is assuming that 2 5/8% was Sn rather than some other alloy. I recall 5% solder but not anything at 2 5/8 percent. That is really low for Sn and an odd amount too. Not 2% not 3% but 2 5/8% rather weird.

[PBaholic]

Maybe the 2 5/8% is Silver Solder. 2 - 3% Silver is a common alloy for Silver solder.

No idea on the No. 20.

Can you do a hardness test before you melt it???

[RogerDat]

Pencil check, or for casual checks I use a spring loaded prick punch and compare the dimple to dimple made in known hardness lead.
Can tell difference between plain, WW, and Linotype "in the field" with that prick punch.
Pencils are probably good to a 3 points of BHN +/- 1 either way.

How hard is silver solder?

I won't melt it until I decide to use it for casting, silver solder is high tin solder as I recall, be sort of a waste to use it at 50/50 WW mix for plinking ammo. But I found this at 2.5% silver the rest lead, zero tin, zip, nada. http://www.jm-metaljoining.com/pdfs-products/A25.pdf And I also find some stuff listed as tin with 2.5% silver.

[country gent]

It may also be a body solder from the days before bondo when holes and dings were "leaded" in

[PBaholic]

How hard is silver solder?

Good question!

I don't know. I have some that I got with some other lead, but it's in wire form, and I can't test it in the form. I've saving it for when I need to solder some obscure metals.

I would assume harder, but I don't know by how much. You would think this would be somewhere on the Internet, but I did a little searching, and came up with nothing. I have some text books and they show Silver being a BHN of both 35 and 90, so I can't even guess.

[BNE]

How hard is silver solder?

I won't melt it until I decide to use it for casting, silver solder is high tin solder as I recall, be sort of a waste to use it at 50/50 WW mix for plinking ammo. But I found this at 2.5% silver the rest lead, zero tin, zip, nada. http://www.jm-metaljoining.com/pdfs-products/A25.pdf And I also find some stuff listed as tin with 2.5% silver.

I had a member here test some alloy I have with 2.5% Silver. It tested very similar to clip on wheel weight.

2.5% Silver is close to the lead/ silver eutectic point. A eutectic alloy melts like water. There is no "slushy" phase. It is a solid at one temp and then when the temp is raised one degree, it turns to liquid. Silver readily alloys (Mixes with) Lead. It alloys better than Tin. It also toughens the lead more than it hardens the lead. I think it would make a great alloy for HP bullets, but that is only an opinion right now!

[jsizemore]

You can't have too much info:


Melting Point of Eutectics of Lead with Other Metals:

other metal per cent by weight temp. ° c.

Silver Ag 2.3 304

Arsenic As 2.8 292

Gold Au 15 215

Barium Ba 4.5 291

Bismuth Bi 56.5 125

Cadmium... Cd 17.4 248

Magnesium, . Mg 3 250

Palladium . . . Pd 5 265

Platinum. . . . Pt 5 290

Antimony . .Sb 12.5 251

Tin.........Sn 62 183

Zinc Zn .5 318

[garym1a2]

We used tons of silver solder on our rectifier line. Melts at 221C. Is very strong and good for high temp applications. We used 96.5SN/3.5 AG and 97/3

[RogerDat]

Thanks to member BNE I have an answer. don't know why it is stamped 2 - 5/8% but it should make some nice bullets or for adding into a big batch. The No. 20 with line of stars is essentially straight solder.

Sample 2 - 5/8% Solder Sticks
Pb = 92.1%
Sb = 4.7%
Sn = 3.2%

Sample # 20 Quality Solder With stars in a row
Pb = 76.7%
Sb = 0.1%
Sn = 23.2%

Along with that I found 3 @ 5# ingots that turned out to be wiping solder, looked like the ingots our local phone company used for sealing the seams in lead wrapped underground cable so despite top markings having been hammered to the point they were unreadable I bought those also. Those were 35% Sn. So certainly not a wasted trip to the scrap yard.

[lightman]

I bought a 2 gallon bucket of odd solder a while back. Many of the rolls were still full or nearly full and a few of them were still in the original box. Unfortunately the bucket had gotten wet and I could not read the labels. There were a few metal rolls that had rusted and come apart. I'll melt it all together and have a sample tested.

[RogerDat]

I do the same thing. I melt a big batch with my collection or roll solder or small bits of bar solder. I pour mine in those small candy or mini muffin tins about 1/4 inch deep. I use a salad bar dressing ladle getting about 2 coins per ladle full. That approach makes solder "coins" which are a good size to work with. Getting a whole bucket of solder at once is quite a score. I usually only have around 5# or so that I accumulate over summer of garage sales or from scrap yard bin. Range has been everything from 23% to 53% Sn. I think the higher Sn amounts came from suspected pewter picture frames going into the pot.

One thing I have found out is never do solder in your casting pot. Rosin core solder is not so bad, it will burn off like flux and does no real harm but the acid core solder is hard on the equipment and one doesn't want any acid core residue to end up cast into the next batch of bullets. I always use a thrift store pot for scrap solder over burner or hot plate.

[lightman]

I expect some of this is going to be acid core. I'm about to order a stainless steel stock pot off of Amazon for smelting the solder and the rare odd batch of lead. I hit 5 thrift stores the other day looking for a pot without finding anything suitable. I did make my first pewter score! A small dish on a stem. Not very heavy but it was only 50 cents! I think there was a nice platter at one of the stores but it was $25.

I'm undecided about what to cast the solder in. I'm thinking about the 2 smaller cavities in an aluminum Lee ingot mold.