Soldering Paste ?

[Michael J. Spangler]

Hi guys and gals.

Have anyone used this for alloying? My local Sears is closing down and they had a few 4oz jars of lead free solder paste for 90% off of the $16.99 price tag.

I figured I would grab the 5 there and use them for something.

I was wondering if they would've good for alloying while smelting. There's not much there but the price seemed right.

I also grabbed some (13) 1oz coils of lead free solder. I believe 97/3 for 34 cents a roll.
Sounded like a good idea at the time
Thanks guys! I'm going to see if I can find an MSDS sheet on this solder.

[Outpost75]

Good score! Yes, I prefer and use a commercial flux.

[lightman]

I don't know much about the solder paste but the solder was a good find. 37 cents an oz is less than $6 a pound. Not a bad price.

[Michael J. Spangler]

Thanks man.

yeah i figured the paste is mostly solder. with the flux mixed in. i'll try to find an MSDS with some specifics. i'm sure it will work for alloying during smelting. can't see why not. solder and flux are both good right?

[Jeffrey]

Soldering flux is NOT your friend. Brands like "Nokorode" are hydrochloric acid in a petroleum jelly base: BAAAD FUMES. Other brands are zinc oxide dissolved in a petroleum jelly base. These are primarily used in soft soldering copper pipe. For our purposes "flux" is a totally different animal than plumbing "flux". The solder is likely a good deal. It is probably 97% tin / 3% copper: very good for making boolit alloy.

[bangerjim]

You do NOT want to use soldering flux "paste" for anything to do with re-melting and fluxing lead.

As said: what we call "fluxing" here is not what that solder fluxing stuff does. Soldering paste is used for "tinning" copper and brass for soldering with either an iron or flame. It will make a mess in your pot and if acid based, create hazardous fumes.

Keep the paste for sweting copper pipes! I use it all the time. Use the rolls of solder for sweetening your mix up to 2% Sn.

Use pine sawdust in your re-melting pot to flux your alloy. And Beeswax in your casting pot to reduce the Sn back in.

Have fun!

banger

[Michael J. Spangler]

Thanks guys.
I knew some knowledgeable people would chime in if I posted here.
Figured it wouldn't hurt to have it laying around. On the off chance that is was useful I didn't want to leave it there considering the 90% savings. I'll keep it for plumbing work around the house.

The poor little coils of solder on the other hand will most likely end up in the pot.

Can't wait for yard sale season to kick in so I can get my hands on some more solder.

[Cowboy_Dan]

I'm waiting for yardsale season too. Last year I found a box with 25# of solder in it for $10. Not expecting that kind of a find again, but you also find pewter at them.

[scottfire1957]

Soooo, you wasted your money on the soldering flux? Didn't research before buying? Or, do I thank you for warning me before I buy some?

[Michael J. Spangler]

I think it would be fine for smelting. It can have some nasty flux in it that you don't want to breathe in I guess. Some that can corrode your tools etc. I'm sure it would melt in fine and alloy fine too. Just not really optimal.
I wasn't going to wait on researching because at 90% off it wasn't going to be there that afternoon.
Figured the few dollars I spent was no big deal and I could use it for soldering pipes if need be.

So basically don't bother buying any really

[too many things]

didn't know anyone still used copper and solder. HD hasn't had a shipment of copper fittings this year. sell maybe 1 or 2 a month

[Michael J. Spangler]

Yeah I hear there are some new fancy snap together copper fittings. There's that plastic tubing too.

[deepwater]

$16.99 for 4 ozs. seems high for flux. Is it "paste solder", which is brushed on and then heated to join the parts? If so, then it is primarily solder with some flux. Still a fume issue, but yields alloy.

Rereading OP, it says "lead free solder paste", which is mostly tin.


deepwater

[Michael J. Spangler]

Yeah that's the stuff. It's not just a flux it's the powdered alloy and flux mixed together.

[Geezer in NH]

I would pass

[wadcutter]

It's probably RMA (resin mildly activated) flux which is not corrosive. Industrial pastes using in electric soldering can contain strong organic acid fluxes, but they don't sell them at Sears. You don't want to breath in the fumes regardless.

Most solder pastes are 88-90 solder by weight.

I often melt down solder pastes. Generally I will let it melt outdoors in a pot with a light cover over the pot to keep the fumes down. Once it's liquid turn off the heat and let it solidify. Then most of the flux can be scrapped off the top. If you leave the cover off you will generate a tremendous amount of wife-angering smoke.

[Michael J. Spangler]

It's probably RMA (resin mildly activated) flux which is not corrosive. Industrial pastes using in electric soldering can contain strong organic acid fluxes, but they don't sell them at Sears. You don't want to breath in the fumes regardless.

Most solder pastes are 88-90 solder by weight.

I often melt down solder pastes. Generally I will let it melt outdoors in a pot with a light cover over the pot to keep the fumes down. Once it's liquid turn off the heat and let it solidify. Then most of the flux can be scrapped off the top. If you leave the cover off you will generate a tremendous amount of wife-angering smoke.

That's damn good advice

I might just melt it all up and make a little cake out of it. Scrape off the nasty stuff and further process. Thanks man!