Barrel lug repair?? Solder paste??

I've used the silver-bearing paste solder (Stay brite?) for all lugs and sights with great success and it is plenty strong (ballpein hammer tap test). The steel or brass must be clean, but that is no different than with other solders....

The other question I have on it's use is,,,,
Is the paste sticky enough to adhere to the barrel if I place the lug in it's inlet in the stock, put some past on it, set the barrel in the barrel channel, then gently lift the barrel out?I figure this will get my placement on the barrel such that I won't need to mess with redrilling the hole for the pin in the lug.

Silver bearing solder is good stuff, very strong for it's lower working temperature. Guess I don't need to say much, BH got it covered. What I do personally for lugs is:

Clean/ flux the area, place a small amount of solder in the lug hole, use safety wire to secure it down, heat and go. Watch that you don't overheat the area or you will scorch the solder and weaken it's hold. When properly heated it should obviously look like liquid silver, if it starts turning yellow you have overheated the area of repair.

Go for it!

Unfortunately no, I doubt the paste will stick the lug to the barrel strong enough, in the manner you describe and desire.  

As far as trying to solder the lug back on, without the need to re-drill the hole afterwards, I also seriously doubt that would be possible.

Can you tell where the lug should sit on the barrel by the outline of the old solder on the barrel or perhaps where the browning didn't brown the barrel metal?

Gus

Hi Keith,

"Silver Paste" is a Low Temp Silver solder that doesn't require near as hot of temperatures to flow as High Temp Silver Solder or even higher Brazing temperatures, the latter two can harm a steel barrel if not done very carefully.  As much as I have used High Temp Silver Solder to solder many front sights to the slides of .45 pistols and the needed heat to do it, I would NEVER use High Temp Silver Solder or Brazing on a steel barrel.  I have soldered higher front sights on dozens of BP UnCivil War Rife Muskets and Rifles and Low Temp Silver Solder works great for that as well.  

Yet properly done, Silver Paste is plenty strong enough to hold barrel lugs.  As with any soldering job though, the metals to be joined have to be clean so the solder can stick to both surfaces AND the solder has to flow properly (as has been well explained by others above).  One thing I would add is to keep the torch moving slowly around the lug to heat it slowly and carefully and then you get the best success with the solder properly flowing at the correct heat.

One must first mark the spot the lug will go on.  Often, you can get that by the bare metal and or the traces of solder still on the barrel when the first solder joint failed. Personally, I scribe a line around the lug that scratches a bit into the surface of the metal all the way around.  It will later be covered by the solder. After thoroughly cleaning both surfaces to bare metal where it will be soldered, the next step is to flux and then "tin" or get a thin layer of Silver Paste on the bottom of the lug and let that cool, then clean the bottom of that thin surface layer of solder.  I often use a little 150 Emory Cloth (sandpaper for metal) for that and then flux it again.  

Black Hand mentioned using wire to hold the lug so it doesn't slip as the solder flows.  It is even better if the lug is held with a spring clamp that will keep pressure on the lug as the solder melts, so it doesn't slip as easily.  A spring clamp like this is often REAL handy and just remember to cut the vinyl tip off one jaw and that's the jaw to put directly on the lug.  
www.homedepot.com/p/HDX-2-in-Spring-Clamp-80002/100027346

Gus