Runnin' and you other gents -- I think you're going about soldering underribs the hard way. Call up the Brownell's website (or phone, if that's your preference) and order a container of Swif. It's solder ground into a paste. Buy a pound, not the little squishy tube -- it lasts forever and you'll use it all eventually.) You simply clean the bottom of the barrel and the bottom of the underrib with solvent (I use acetone) to remove any grease, spread a thin layer of Swif on the barrel, clamp the underrib into place, and use your propane torch until until the solder melts (you can see tiny beads of molten solder and some black stuff squish out between the two parts), use your solder brush to sweep away any excess, and you're done. I solder underribs and thimbles (half-stock) all in the same operation. I forget the tensile strength of Swif, but it's very strong. Never had one come loose. All this $#@* about "tinning," etc., etc., is just a waste of time. Unless, of course, you're one of those traditionalists who like to do things the "old way" (read: "hard way"). Good luck~! -- paulallen, tucson az