Anybody have any suggestions for a good BATF-approved method of doing this, for someone with no welding experience? Is (over 1200 degree) silver solder hard to do?

Use Hi temp Silver solder, very simple to use. Clean and degrease, remove finsh of joining componets, Apply heat[ MAPP gas] to a dull red in color. All done

I'm having a bit of difficulty with this, I guess due to my very limited welding/soldering experience. I can't quite seem to get a persistent red glow from the extension. I barely managed to get a very sloppy/ugly solder glop around the barrel in a "c" shape covering almost 50% of the circumference. I have a couple of questions. What percentage of silver should I be using? Maybe the stuff I borrowed from a fisherman friend is too high temp? How much of the circle needs to be covered for this to be legal? I screwed the extension down completely before soldering. Should I have left a gap? Can I grind down the ugly parts after the job is done, or is that not kosher?

farscrape...when silver soldering, make sure that the two items to be joined are brought down to bare metal, to be totally free of any previous finish or lubricant. Also, a proper silver solder flux must be applied to only the areas you wish to join. Not only does the proper flux aid in further cleaning, during the heating process it helps the solder flow between the two materials.

With a suitable torch utilizing either MAPP gas or an Oxy-Acet rig, start to apply heat to the thickest of the two items first, which in this case would be the extension. Keep the flame from the torch away from the area where you wish to apply the solder to, as doing so will prematurely burn away the flux in that area and you will also run the chance of adding contaminants from the flame (if improperly set up, ie., a carbonizing flame, or two little O²) directly into the solder joint. Try to move the torch around evenly, working from the bottom up (remember heat rises!). For every 30 seconds spent heating the extension, heat the end of the barrel closest to the extension for 10 seconds, and go back and forth like so. As both items begin to heat up you will notice that the flux paste will begin to liquify and bubble; not to worry, you are getting close to the desired temperature. Now, while you continue to heat the objects from below, you will see your parts starting to change to a dull red color, and when you see this, rub some of the silver solder wire (or rod as the case may be) onto the area you wish to join and see if it flows into the joint; if not, continue heating until the solder flows easily into the joint from the top. When everything is the proper temperature the solder will be drawn into the joint effortlessly, providing a proper and strong joint.

Silver soldering is NO different than soft soldering a 1/2" copper water supply line in your home, other than the temperature range required to melt the solder. 'Hope it works out for ya'...

Andy (8^)