Soldering sights and under lugs

[old dog]

I am looking for tips on holding sights and underlugs in place in place while soldering.  I find hose clamps to large.
Thanks in advance,Old Dog

[D. Taylor Sapergia]

First, clamp your barrel to a table and level it, ie:  use a level to ensure that the flat top of the barrel is level.
Second, take a single cut mill bastard file with the handle end in your left hand, and place the level on top of it, then on top of the barrel where you want to solder on your front sight or barrel tenon.
Draw the file toward yourself for a couple of inches, ensuring that your level's bubble stays in it's centre.  that will mark the barrel with a light straight line exactly in the centre.
Take a strip of banding steel about 5/8" - 3/4" wide and five inches long.  In one end, cut a notch that will fit over your sight or tenon, using a saw or file.  Bend the strap to 90 degrees about 1/2" in from your notch.  This is your clamp.
Once you have tinned the barrel and the sight/lug, flux the barrel again and place your item on the centre line you've made, with the clamp's notch on the item, it's long end extending down the barrel.  Clamp the strap to the barrel with a spring clamp, "C" clamp, or hose clamp,  The strap will hold the item securly to the barrel while you heat the barrel from underneath until the solder flows. Add more solder to the joint and it will flow into the joint.
Once cool, remove the clamps, cut away the excess solder with a graver, knife, files and abrasive cloth/paper.
Done.

[Scota4570]

I use these pliers and C-clamps for that.

[Clark Badgett]

This is what Taylor is describing

[Not English]

I use small 3" or so C clamps. They're cheap if ruined. I've also used dead soft steel wire that is wrapped around the sight/lug and the barrel and then twisted tight.

[davec2]

The beauty of the type of spring clamp that Taylor describes and that Clark has shown a picture of is that the spring steel strap keeps a constant tension on the sight or tenon without marring the barrel (or whatever you are soldering to) and mass of the clamp itself does not act as a heat sink robbing heat from the joint you are trying to make.  Also since there is no spring to the C clamp or even the Vise Grips once applied, they can easily let go during the soldering job making a mess that you would have to deal with after everything cools down.  Believe me I have used the wire trick, the clamps, the Vise Grips and probably about a hundred other ways to make solder joints from low temperature to 1800 degrees and on things from as small as a 0.5 mm gold chain repair to the nozzle of a Space Shuttle main engine.  They all work one way or another but for this particular task, you can't beat the spring clamp Taylor and Clark are describing.  Besides, it cost nothing to make from a piece of scrap strapping.

[old dog]

Thanks guys.  I am disappointed I didn't think of this myself.
Old Dog

[flehto]

I've used the pictured clamp bar for  soldering the bbl lugs and  front sights on round bbls as well as a bbl lug at the waist on octagon bbls.  A parallel clamp is used on the flat end and the vertical length w/ a ""V" notch holds the lug  or sight. The clamp bar is made from a length of hot rolled steel 1" wide  X 1/8" thick. ....Fred