View Full Version : Silver solder strong enough to join shotgun barrel lug?
February 8, 2005, 01:19 AM
Hey there, first I want to thank all that replied to my question about ramped barrels for 1911s.
I have been working on a Mossberg project gun and now have a custom-length barrel and custom-length magazine (longer). I would like to join the barrel to the magazine tube like the original system. I have milled a new barrel lug from 1018 steel and am ready to join it to the barrel. Is silver solder strong enough for this application? I don't know how its strength compares to brazing, but am guessing it's not as strong as a TIG weld. (Unfortunately it's the TIG welder I lack.)
PS: The gun is a 12 ga. Mossberg 500A and will be shooting up to 3" magnums, so if it's not as strong as stock I don't want it.
February 8, 2005, 06:20 AM
Yes silversolder will be strong enough to handle the job. It is how the factories do it. The problem will be that once you solder the two together, you will ruin the heat treatment of the barrel. Sending back to the factory is usually the best way to take care of the heat treament issue.
As to strength, the silver solder is not as strong as brazing, and brazing is not as strong as welding, whether it is tig, mig , or arc.
February 9, 2005, 05:12 PM
I feel for your project that "silvaloy" or the strip silver solder is fine. At Novaks we use it to silver-solder blocks of steel on slides that will have a dovetail milled into it - now that's strength.
I'd call Brownells "crew" and ask for their preference. On your shotgun it ought to be just fine - also, ask them about the flux they prefer with the solder you get! :)
P.S.: I'd be sure to get a full contact fit as I'm sure you will!
February 9, 2005, 06:03 PM
What do you mean by 'silver solder '?? This is a confusing term since there is a low temperature "solder" 400F and there are high temperature silver "brazes" 1100-1200F .There is a great difference in strength. For your application I would say braze is ok , solder is not.
February 10, 2005, 12:53 AM
That's what it has always been called. Just know if you braze or silver solder, which is used at higher temps, you will need to have it heat treated and not just normalized.
February 10, 2005, 11:56 AM
Greater than 840F melting of the filler is brazing. True silver soldering is a brazing process.
The low temperature solders are called ‘silver bearing’ solders. They are not as strong and are still ‘soft’ solders.
There are a number of plumbing solders with a few percent silver to improve performance. The alloys are Tin-Copper-Silver, instead if the original lead free tin-antimony formulations. Oatey has a patent on the use of the silver in these solders.
There are hundreds of brazing rod formulations but silver-copper alloys are probably the lions share. Phosphorous can be used to produce a self fluxing rod.
February 11, 2005, 10:05 AM
I checked with my mechanical engineer who pointed out that shotgun barrels are normally soft soldered together. This is the reasn a double barrel cannot be hot tank blued. The solder will soften at the bluing temperature.
If the mag tube is joined to the barrel soft solder is likely to be strong enough.
February 17, 2005, 09:51 PM
I don't know about Mossberg , but factories generally use electric brazing for that kind of thing; it's not a DIY job. It will be hard to use brazing or silver solder without softening a considerable area of the barrel. Soft solder might be good enough, although a barrel band would be my choice.
Edited to add: Well, I said that, didn't I? But I checked a couple of places and can't find the figure 8 type of barrel band that used to be available for just that kind of job. They were open at the top so as not to get in the way of the sight. So, IF you can find one, a barrel band would be my choice.
February 18, 2005, 12:16 AM
Hey Jim, actually I can make a barrel band. I didn't think of it - thanks for planting the idea though!
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