Other than an oxyacetylene torch, a DA grinder, and some rags, here’s what you’ll need for lead work: a cartridge respirator, paddle lube, aluminum body tape, scissors, a pencil, an acid brush, a wooden paddle, a countersink, tinning compound, and lead solder sticks. Other than an oxyacetylene torch, a DA grinder, and some rags, here’s what you’l Cutting loose the body side mouldings from our 1970 Dart left a row of mounting holes along the delicate character line. Plastic filler would require dimpling the holes to gain a modest chance of it properly adhering and would necessitate slopping it along the full length of the body and blocking in a new line. With lead, the surface thickness of the repair is negligible, preserving the original line. Prep for solder by sanding to bare metal around the hole. Cutting loose the body side mouldings from our 1970 Dart left a row of mounting holes alon Next, use the countersinking bit to clean the inner edge and provide a larger, tapered surface area for the lead plug to bite Next, use the countersinking bit to clean the inner edge and provide a larger, tapered sur Now the hole is ready for tinning flux. While some brands come as a premixed paste, we used Dutch Boy Acro-Tin, which is the dry-powder type. Forget the instructions on the can--just stir up your own paste with tap water. Mix to a heavy consistency about as thick as valve lapping compound. Make only enough for the job at hand. Now the hole is ready for tinning flux. While some brands come as a premixed paste, we use Using the acid brush, paint the edges of the hole and a half-inch area around it with the tinning slurry. Using the acid brush, paint the edges of the hole and a half-inch area around it with the Using a small torch tip (Victor No. 000 used here), play the flame evenly around the tinning paste until the solder in it melts to the repair area. A low, even flame is all it takes; hold back the tip a couple of inches to control the heat. Remember, we’re not welding here. The tinning compound will turn bright as the area is tinned, telling you when it’s done. Using a small torch tip (Victor No. 000 used here), play the flame evenly around the tinni While the tinning film is still warm, wipe it with a damp cotton rag to clean off the flux and debris at the surface. One thorough wipe works best. While the tinning film is still warm, wipe it with a damp cotton rag to clean off the flux With the area tinned, the body solder has something to stick to. Play the flame over the repair area and the lead stick, and drop enough solder to fill the hole, placing it just above the hole. The trick is to dab and rotate the lead stick as its tip begins to melt. With the area tinned, the body solder has something to stick to. Play the flame over the r This is about the right size for the lump of lead deposited adjacent to the hole. The lead can be heated and moved anywhere on the tinned area. We positioned it above the hole so that it can be dropped like a curtain over the repair. This is about the right size for the lump of lead deposited adjacent to the hole. The lead Spread the heated lead with the wooden paddle. In keeping with our low-buck approach, our paddle was harvested from a broom handle and sanded to shape. To prevent the lead from sticking to the paddle and smearing, the paddle must be lubed by playing some heat on the business end of the paddle (don’t burn it) and sliding it over the lube. Once coated, warm the lubed area and wipe off any excess with a dry rag. To move the lead, again play a low heat in the area of the repair, and when it just starts to yield (check by jabbing with the paddle), spread the solder into position. Spread the heated lead with the wooden paddle. In keeping with our low-buck approach, our Work the lead until it smoothly covers the repair area. Controlling the heat with the torch position is key, although it’s not too tricky after some practice. Overheat the lead and it’ll drop out; try and work it when it’s too cold and it’ll get too grainy as you spread it. Finally, don’t blast the paddle directly with the flame--it’s wood, you know. Work the lead until it smoothly covers the repair area. Controlling the heat with the torc While finishing large areas generally calls for the lead file, the DA sander alone will get the job done handily for a simple hole repair. The lead should be feathered into the surrounding sheetmetal rather than ground down to a button. We used a 40-grit sanding disk with the DA locked off to the grind setting to quickly feather the repair and then reset to orbital mode for the final blend. While finishing large areas generally calls for the lead file, the DA sander alone will ge The almost invisible finished metal repair is blended smoothly into the surrounding sheetmetal and, unlike plastic, won’t drop out or put a crowned area over the repair. The entire leading process can be completed in about two minutes or about the time it takes for a hot mix of plastic to cure. Finish with metal prep/conditioner to clean and primer up. The almost invisible finished metal repair is blended smoothly into the surrounding sheetm The last thing we want to see on the backside of holes such as these, which are visible from inside the trunk, is the rough side of the repair. Sure, the inside can be ground and finished to impress the local alignment man, but crawling under the wheelwell to wield a sander is undeserved penance The last thing we want to see on the backside of holes such as these, which are visible fr The trick is to back up the repair with aluminum body tape, which actually forms a mold at the back of the hole. The problem is that the adhesive will flame up and the residue will foul the repair. The ruse? Cut a button of tape slightly larger than the hole and stick it shiny side up to the center of a piece of backing tape. The trick is to back up the repair with aluminum body tape, which actually forms a mold at Mark the center of the tape button so that it can be lined up with the center of the hole. Mark the center of the tape button so that it can be lined up with the center of the hole. Tape won’t stick to an oily, wet, or dirty surface, so clean the backing area thoroughly. Finish by centering the tape button over the hole and pressing the backing tape firmly to the surface. Tape won’t stick to an oily, wet, or dirty surface, so clean the backing area thoroug No, it’s not the latest image from the Mars Pathfinder but rather the factory-painted undercoating on the inside of our Dart’s trunk. With the backing tape removed, the inside of our repair is perfectly formed to the inner surface. Notice that the heat of the leading process was so low that even the asphalt undercoat immediately surrounding the hole was left unscathed. Try that with your MIG or brass rod. No, it’s not the latest image from the Mars Pathfinder but rather the factory-painted Lead is a mysterious medieval substance. As used in bodywork, lead is revered by tradition but regarded as the dwindling domain of weary sages and old-world diehards. Leadloading has been all but forgotten by the unleaded generation, as modern plastic body-fillers have become the standard fare. The truth is, both have a place in the car crafter’s toolbox, each having its advantages in a given application. Plastic is at its best as a thin glaze over a repaired area. Where lead truly shines is in applications in which its structural strength, superior bond to the base metal, and lack of porosity are used to an advantage. Lead, or body solder, is typically an alloy of tin and lead (usually a 30/70 mix, respectively) similar to the solders used on radiators and in electrical work. What aren’t as familiar are the techniques employed when body solder is used. Far from requiring years of old-world apprenticeship, dabbling in lead dabbing can be quickly mastered by anyone familiar with handling a torch. Uses for lead in body repair can run from seam sealing to metal-finishing panel repairs to filling various body holes. The latter is the most relevant application for the neophyte metal fan and fortunately one of the easiest techniques to master. Our saga began with a 1970 Dart Swinger 340. Removing the optional body side-moulding, we were faced with 48 1/4-inch holes riddling the delicate midsection of the virgin sheetmetal. Welding or brazing the hole is a high-heat process that would invariably creates some panel distortion, and stuffing holes with plastic filler is an inferior repair, temporary at best. Lead offered the only real choice. The accompanying photos detail the metal mayhem, proving that with a bit of old-time alchemy, even an uncouth tech writer can be transformed into a metal master SOURCES 4 to 1 Manufacturing 23052 Lake Forest Dr., Ste. B-4 Laguna Hills CA 92653 M.I.T. 1112 Pioneer Way El Cajon CA 92020 Currie Enterprises 7-14/-528-6957 www.currieenterprises.com Rubicon Express rubiconexpress.com JB Conversions Inc. 132 P.O. Box 2683 Sulphur LA 70664 Six States Distributors 1112 W. 33rd S. Ogden UT 84401 Enjoyed this Post? 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