Edge lipping is a gauge for turning the edges up on panels allow for a better fusion weld. Fusion welding is allowing the base metals to puddle together, as they cool they become one to create a very ductile (soft) joint without using any filler rod. The joined lips can be raised easily with a panel beater and dolly, on a forming head or with a English wheel or Planishing hammer.  Long used by English coach builders, lipping can be done on steel as well as aluminum (will require flux). A great alternative to traditional butt welded seams, especially where you want to control the heat affected zone or where it will particularly difficult to finish a panel area after assembly. Panel lipping does require access to both side of the panel but works when joining patch panels with older metal to newer metal.  Edge lipping requires oxy/fuel welding but can be done equally well with Tig welding. 6" OAL and offers a 3 1/2" lipping zone, bench or vise mount. Full instructions included and can be easily used by all skill level persons. You'll be very impressed with the quality and uniformity of your seam and what a time saver no grinding and only light sanding........  Now includes our DPBRMO 1 1/2" diameter barrel/bossing mallet.