Silver solder questions

[hawkenhunter50]

Looking for a little guidance on silver solder. I have this roll Sn 96.5 Ag 3 Cu0.5.

Will this work for silver soldering parts?
Anyone know what the flux 4300 3.3% means?
Why would solder have an expiration date?

Thanks in advance.

 

[64Springer]

Clean some metal and do some testing.

Steel on steel.

Brass on steel.

Figure out what temp it flows at.

 

[44Bro]

That's common lead free flux core plumbing solder. Flow temp will be around 400-500 F. The flux number is the type (acid, rosin, whatever) The 3.3% is the amount of flux in the core. Silver solder for parts has a much higher silver content, all the way up to pure Ag.

 

[TDM]

Go with the highest silver content you can find. And practice with it.

 

[The Crisco Kid]

If you're soldering something that doesn't have much load on it you can use a low silver content or none at all like 50/50 tin/lead. The more strength you need the higher the silver content you need. Like they say, practice some before you do it for real.

 

[hawkenhunter50]

How much silver content is the minimum for parts with stress? For now it'll be for low loads/stress. What silver content would be acceptable for something like barrel tenons being soldered on? Thanks for the advice so far.

 

[44Bro]

How much silver content is the minimum for parts with stress? For now it'll be for low loads/stress. What silver content would be acceptable for something like barrel tenons being soldered on? Thanks for the advice so far.

The 35% or 45% types from Harris will probably do anything you need.
Harris solders

 

[hawkenhunter50]

The 35% or 45% types from Harris will probably do anything you need.
Harris solders

Thank you

 

[aussie pete]

Google, 'Why does silver solder with flux have an expiry date?" You will be in for some good reading. Spoiler alert, long story short, it is because the flux breaks down with time (and fluctuating temperature) becoming ineffective. Man, there's some gumph I didn't know.

The stuff you lads get me chasing! Life long learning at its best.

Pete

 

[hawkenhunter50]

Thanks for the info Aussie, weird though I don't recall seeing expiration dates on cans of flux, maybe a difference in flux types??? Or maybe I just never paid close enough attention to the flux cans I've used.

 

[tgfrench]

The 35% or 45% types from Harris will probably do anything you need.
Harris solders

Yeah at north of $70 a roll. Not saying it isn't worth it. But cost per use. Lordy lordy

 

[FlinterNick]

Home Depot sells a pretty good metal solder that i use on brass.

For under lugs I use Brownells hi force 44

 

[ZUG]

I went to their home site and it looks to me that this silver solder is for plumbing/air condition work not for steel. This solder would be good for brass and copper but not for steel - that's what I get out of their info.

 

[BJHabermehl]

High silver content solders need much higher temperatures to flow. Normal plumbing solder 5 percent silver and the rest tin works well for underlugs, ribs and sights. Useing high temperature silver solders can easily destroy a gun barrel due to warping or scaling the bore. BJH

 

[LRB]

For high strength, Brownell's Silvaloy 355. 56% silver. Can be used with propane with a Mapp gas torch head. Requires a borax flux. Flows around 1250°F. Next down is Brownell's high temp Force 44.

 

[hawkenhunter50]

BJH and LRB, thanks for the info.