Silver Solder Paste ?
- Thread starter Loyer
- Start date
NO
Silver solder paste/tinning butter & alloy is NOT used in the firearms industry,since it is only as strong as soft solder.
Silver BRAZE or Copper BRAZE is used in the industry.
A few different types of "silver solder"...
The most common I used had a high melting temperature... so high steel would glow red, usually requires cleaning up, polishing and bluing ... sights installed with that never fell off. Parts repaired with that lasted.
Brownells offer a low melting soft solder (Force 44) that will withstand being in a hot bluing tank. It requires it's own flux (Force 44) as well. The best for soldering barrels/ ribs, sights, etc where you do not want the complications of the silver solder mentioned above ... Ordinary soft solder gets eaten by bluing salts and is very outdated when it comes to firearms.
The most common I used had a high melting temperature... so high steel would glow red, usually requires cleaning up, polishing and bluing ... sights installed with that never fell off. Parts repaired with that lasted.
Brownells offer a low melting soft solder (Force 44) that will withstand being in a hot bluing tank. It requires it's own flux (Force 44) as well. The best for soldering barrels/ ribs, sights, etc where you do not want the complications of the silver solder mentioned above ... Ordinary soft solder gets eaten by bluing salts and is very outdated when it comes to firearms.
- Location
- Western Manitoba
I think Brownells sells or used to sell a 3% or 4% silver bearing solder for "gunsmith" work - I had tried to buy some, but they could not or would not send the specific flux for that stuff. I found equivalent within Canada - Amazon.ca, I think - similar solder and the flux. I have used it to "glue on" a front sight ramp on a rifle barrel - likely several square centimetres of contact area - that ramp has not fallen off yet. But, as mentioned in Post #2 - Silver braze and Copper based braze is MUCH stronger, and probably used more often - it also requires the parent steel to be nearly or more than "red hot" to "stick" - unlike the silver bearing "soft" solder. There are many applications - sometimes more than one thing works okay - sometimes only one thing is the "best" for that job. Is also a skill and cost factor at work - some factories will use an induction brazing - many after market people will use a micro-TIG process to get to the same connection - not the same, but different approaches to get there.
The REAL answer, is, "It Depends!"
There are millions of Mil-Surp guns out there that still have their sights (and other parts) soldered on with what was basically Plumbing Solder, the typical 70-30 lead-tin mix.
Brownells has sold a LOT of their silver bearing solder (I want to call it 440, for the melting temp, IIRC), with a couple percent silver in the mix, and guys have been happy with the results. A 'little' bit tougher than plumbers solder.
Edit: Hi-Force 44 solder is what they call it!
Real silver solder is closer to a Brazing Rod, than it is to Soldering with lead-tin solder. The heats required are much higher, and so is the risk that those heats cause you other issues, mostly in the formation of scale, on interior surfaces.
As to "Pastes", I personally have not had much luck with the few I have tried (admittedly for electronics work), which may have been my technique, or it may have been otherwise. But I am pretty fond of sticks of silver solder, or rolls of solder wire, with or without flux.
There are millions of Mil-Surp guns out there that still have their sights (and other parts) soldered on with what was basically Plumbing Solder, the typical 70-30 lead-tin mix.
Brownells has sold a LOT of their silver bearing solder (I want to call it 440, for the melting temp, IIRC), with a couple percent silver in the mix, and guys have been happy with the results. A 'little' bit tougher than plumbers solder.
Edit: Hi-Force 44 solder is what they call it!
Real silver solder is closer to a Brazing Rod, than it is to Soldering with lead-tin solder. The heats required are much higher, and so is the risk that those heats cause you other issues, mostly in the formation of scale, on interior surfaces.
As to "Pastes", I personally have not had much luck with the few I have tried (admittedly for electronics work), which may have been my technique, or it may have been otherwise. But I am pretty fond of sticks of silver solder, or rolls of solder wire, with or without flux.
I've used silvabrite for pretty much everything, it's a soft solder containing 4-6% silver melting temp 400-500ish. Depending on which product you use. You can still work with this stuff using a propane or (better) mapp torch.
I was talking to the new neighbor when he moved in last year - an HVAC guy, he was using a high silver content solder on my other neighbors air con (the FNG was in the neighborhood less than a month! haha)
He said it was 15% silver and needed an oxygen/acetylene setup to melt it. Apparently you can get it where HVAC guys shop - never looked any further than that though.
From what I hear (I hear - I do not know) solder that jewelers use can be 60-70% silver.
SO, from what I suspect you are up to (soldering ribs, pipes, drip bars etc) Silvabrite is just fine. Depending on surface area, sights should be fine as well.
If you are looking at really small surface area or something like a bayonet bar/lug - you are gonna want more strength, of course when you start needing oxygen/acetylene and heating parts that much - brazing is also an option.
Basically as mentioned "it depends"
Also, IF you are going to look at the HVAC stuff - read the labels, some of these are designed for other purposes than tensile strength and contain stuff other than tin and silver. So those are your shopping clues: silver content, melting and flow temps, tensile strength.
- Location
- Western Manitoba
This is the stuff that I got on Amazon.ca - is weird because containers say it is made in USA - but Brownells would not send the equivalent flux. Not a paste, so not what OP was asking about. As per Post #6 - I think this stuff like 3% or 4% silver bearing - I use it with propane torch.
Attachments
The HVAC guy was most likely using Silfos 15 which is which is 15% silver with the remaining being copper and phosphorus. It's meant for copper brazing not steel. It's very popular for HVAC work but for gunsmithing you would use silver solder.
- Location
- Blaster land, Okanagan BC
I soldered a set of rifle sight on a shotgun barrel with plumbers solder and paste flux in 2019, they’re not going anywhere. I use it a lot for grouse and shoot slugs out of it regularly, have done a lot of soldering and brazing over the years and with anything how well you clean and prep your surfaces will make a big difference in the strength of the joint. Tinning the parts well is a big help with something like sights, I’m sure the ones I soldered on will outlive me.
Sometimes, a guy doesn’t want to become an expert in something, he just wants to fix a broken item.
This is the product I’ve used an awful lot.
70PA Solder: 16,000 psi tensile strength,
425° F. bond- ing temp. Great for joining dissimilar
metals. Can be Plated Over with Electroless Nickel.
80PA Silver Braze: 85,000 psi tensile strength,
1125° F. bonding temp. Excellent for nickel alloy,
carbide and dissimilars. Can Be Plated Over. 1 oz.
This is the product I’ve used an awful lot.
70PA Solder: 16,000 psi tensile strength,
425° F. bond- ing temp. Great for joining dissimilar
metals. Can be Plated Over with Electroless Nickel.
80PA Silver Braze: 85,000 psi tensile strength,
1125° F. bonding temp. Excellent for nickel alloy,
carbide and dissimilars. Can Be Plated Over. 1 oz.
Jonnyofalltrades
Regular
- Location
- North-central Saskatchewan
I have never used paste, but I've found that Forney silver solder 38116 is the best compromise for availability, strength, and ease of use.
I've used Hi-force 44 a lot. It's fine, but expensive when you consider shipping, and the correct Flux can't be shipped.
"Real" silver solder (1100°ish F) is actually not that hard to use, but it requires an acetylene torch, and the high heat can cause all sorts of damage. Not what I'd recommend for a DIY'er.
I've used Hi-force 44 a lot. It's fine, but expensive when you consider shipping, and the correct Flux can't be shipped.
"Real" silver solder (1100°ish F) is actually not that hard to use, but it requires an acetylene torch, and the high heat can cause all sorts of damage. Not what I'd recommend for a DIY'er.
