silver n lead

[nes4ever69]

i have some small pieces of brazing rods (silver solder) and wonder if it is worth using to replace tin? 15% Silver, 5% Phosphorus, 80% Copper is what they are composed of.

i couldnt find any info on this and was wondering. i have probly 30 1" pieces.

[leadman]

Don't remember the exact term for that rod, but it used to "weld" copper pipes together, usually in refrigeration system. The silver solder I used to use on radiators and such had more lead and tin in it and was silver colored.

I think you may have a hard time melting the copper in the lead melt. If you can go to a welding shop close by or find the rod on the internet it may give you a melting point.

I do know that sometimes babbit has copper in it so it must be compatible with lead.

After I read other threads I found an interesting one by 303GUy a few threads below this one on alloying copper in to the lead malt.

[sagacious]

You may wish to try your own experiments, but Cu/Ag/P in lead is not likely to replace the benefits of tin addition. The brazing rod alloy is not likely to increase fluidity and fillout, reduce surface tension, reduce melt temp, reduce drossing, etc, like tin will. In fact, it is likely to do the exact opposite, as copper increases drossing. Good luck.

[lwknight]

It takes about 1400 degrees to start the melt in that alloy too.
Full liquid melt is around 1550 degrees.
It does make great solder. So much tougher than lead or tin solder
and best of all , no flux or pre cleaning required.

[nes4ever69]

refrigerant lines is what it used for. i was just wondering. looks like it will be expirement time. might not have a low enuff melting point. testing time.

i did read the tinning copper one.

i have heard/read people using silver solder (home depot plumbing stuff) but wasnt sure on this.

[docone31]

That particular stuff makes a real mess. The Phosphorus makes a lot of scale.
It is an high temp brazing wire.
That is not the silver solder they were referring to at Home Depot.
It is self fluxing copper solder/silver solder.

[deerslayer]

I believe the "silver solder" or "brazing rod" you are refering to is a BCUP brazing alloy used in refrigeration and medical gas piping. It is very expensive well over $50 a lb. You may be better served trading it for a good alloy. Even small pieces can be put back together to make another stick of it. There is also true silver solder out there that actually has a high silver content and comes in a small roll sometimes this is used instead of the above for refrigeration.

[nes4ever69]

silv-alloy or something its called. just bought a pound today, $88. its one of those things that is free, the throw away peices, that if it would work, great. but it doesnt seem like it will due to the melting point. in the years of work, many many condensors have been set and lots of little peices have added up. co-workers throw it away, ive collected it.

my thinking was that plumbing solder has silver/tin (i think), this has silver that maybe it could work. doesnt hurt to ask.

[docone31]

This is what that stuff is,
http://www.riogrande.com/MemberArea/...68|4942=Solder
The phosphorus acts like flux. It takes muriatic acid to remove the fire scale. I went through a few pounds of that stuff back when I was making Mokume'Gane.
It was nasty.
It would be good for high temp copper pipe brazeing. It is self fluxing.

[sagacious]

... but it doesnt seem like it will due to the melting point. in the years of work, many many condensors have been set and lots of little peices have added up. co-workers throw it away, ive collected it.

my thinking was that plumbing solder has silver/tin (i think), this has silver that maybe it could work. doesnt hurt to ask.

It'd not melted, it would be dissolved by the lead. Water will dissolve salt, but the salt doesn't have to be heated to melting to dissolve in water. Exactly the same thing happens when copper/antimony/etc dissolves in lead.

Silver solder for plumbing is used for it's tin content, and not the silver content. In the case of your brazing alloy, you're adding copper to lead, and the P and Ag content are of little consequence. One could get the same effect (whatever that is) by tinning a pre-1982 penny ad tossing it into the melt. If it were me, I'd save the brazing rod scraps for brazing, as it only needs to melt to work, and brazing alloy is more epxensive than scrap lead. Good luck.

[nes4ever69]

thank for the input. now i know were i stand on this.

[lwknight]

I have been just tossing the rod stubs too. At about $2.00 per stick and 1 stick will do several joints. Its not worth the hassle of trying to melt the short pieces together to make a long useable stick.

[sagacious]

I have been just tossing the rod stubs too.

I use a big pair of forceps to hold the short rod ends when brazing, or I snip the rod ends into small chunks to use when a small piece of brazing alloy is the best solution for a tight brazement.

[nes4ever69]

i kept them cause a few times ive run out on jobs were the closest parts house would be an hour to get to it.

[Oyeboten]

i have some small pieces of brazing rods (silver solder) and wonder if it is worth using to replace tin? 15% Silver, 5% Phosphorus, 80% Copper is what they are composed of.

i couldnt find any info on this and was wondering. i have probly 30 1" pieces.

This is a Brazing Alloy.


Sadly, there is endless confusion between Brazing Alloys ( Silver and Copper based ) and 'Soldering' Alloys ( Lead based ).


Melting point of the Alloy you mention is probably 8 - 9 hundred degrees anyway...maybe more.

[sagacious]

This is a Brazing Alloy.


Sadly, there is endless confusion between Brazing Alloys ( Silver and Copper based ) and 'Soldering' Alloys ( Lead based ).


Melting point of the Alloy you mention is probably 8 - 9 hundred degrees anyway...maybe more.

Original post does recognize the alloy as such, by specifying "brazing" alloy. Dissolving copper is a different technique than using tin-based solder, but still not likely to benefit the melt in this case.

Regards.

[Oyeboten]

I do not see any benifit for this to be added to a Boolit Melt either...

The Alloy would not impart to Lead the same benifits which Tin does.


I use a lot of this, Silver Brazing 'Sticks' of various compositions, I manufacture a line of specialized Tungsten Carbide Tools which I have to Braze, but I long ago forgot the melting points of the different Silver content Brazing sticks I use. some I can use ( if careful! ) on Brazing together fairly thin Sheet Brass, Steels, odds and ends of various kinds.

Short stubs, I just Torch melt onto the front end of next stick, so they get used up as I go.


Pure Lead, and, enough Tin to suit the specific application, seems about best to my imagination, for Boolits.


Good points there on the distinction between 'Melting' and 'Dissolving', very true..!

[mtgrs737]

I used to work at the Colman heating and Air Conditioning factory in Wichita Kansas and they used a lot of silver brazing rod in the manufacture of their A/C units. They were always trying to find a way to cut down on the silver (Ag) content of the rod to save money but were unsuccessful last I heard. They did use a liquid flux though, in making their assemblies.