ROCKER PANEL REPLACEMENT & BODY WORK
The mechanical phase of restoration on our '53 Buick Roadmaster Coupe is completed. Since the body is partially disassembled for painting, we have only been able to test drive it on short trips, but they have included speeds of 65+mph and high hill climbs to test the Dynaflow transmission. In previous issues, we have covered the rebuilding of the Dynaflow (see the Archives page, www.southernwheels.com). We had trouble with premature front pump failure, due to the torque converter pushing on it, and it appears that problem is fixed. A few more weeks of testing and we will report our findings.
We stripped and sand blasted the '53 just after we brought it home. We already have the stainless and chrome back from Advance Plating in Nashville, and we will have to produce come beautiful paint work to meet the level of the beautiful bright work! The metal work involved the replacement of the driver's rocker panel and filling in some pin holes around the fender wells. If the mother metal on your project is thick and in solid condition, welding up these holes is no problem. However, ours was thin in spots, which can cause the metal to blow away, creating even larger holes as the repair is being made. We called in longtime welder and car buddy Don Pennington. He immediately made some adjustments to our MIG, changing the wire roll to a larger diameter one, set the rollers so that the wire would feed in a more uniform manner instead of "jerking", which can cause holes to blow in the metal. He also turned the settings down and patiently welded up the pin holes. After being ground down, they are now ready for metal prep cleaning and primer. The rocker panel was a bit more of a challenge. These are easy to find, but buyer beware of the quality! We called Gary Bauer at Rocker King (262-549-9583), and he had a panel for us that was made in the 1950s. It fit perfectly! We usually remove the doors to weld in the panel, but the big Buick door swung back far enough so that it wasn't necessary to remove it from the car. The sill plate was removed, and the new rocker was set into place and layout lines were drawn with soap stone.
In removing the old panel, we never use a cutting torch. This could create overheating distorting the metal, and leave rough edges. We use a plasma cutter, sabre saw, or cutting wheel for precise cuts and a smooth welding edge. The cuts are then cleaned up with a wire brush and grinder if necessary.
Don put in the new rocker and tack-welded it into place, then opened and closed the door to check clearance. He put one of the door sill screws in, running it down to about 1/2", then opened and closed the door. If the door just touches the screw, that's how much clearance there is. Our clearance was fine, and our door rubber fit up to the panel nicely. Now it was time to check our outside panel flush fit. The front edge was slightly out from the front fender, so we had to put a dolly on the back side of the panel and hammer it to meet the front fender edge. Even though it will be mostly covered with a stainless strip, we wanted the fit to be flush. The back edge was fine. Don then began to weld in the rocker, skipping around with his welds, since welding in a straight line can warp the panel. When the weld was completed, he hammer-welded the weld seams until they were flush with the car, then ground down all of the welds and filled in the pin holes with the MIG. Before priming, we will clean up everything with a wire brush, finish our highs and lows with a pick hammer and file, and put in some seam sealer at the union under the sill plate.
We always spend time before we start welding to set up a safe working environment, making sure there is adequate ventilation, that there are no flammable materials in the vicinity, that the interior of the car is shielded from sparks, and, of course, body and eye protection, a fire extinguisher and a bucket of water nearby.
When the welding was complete, we moved on to body straightening. Fortunately, the car was mostly straight, with just a few small dents and dings. We had already primed the car and blocked it down with 220 grit paper, so any needed body work was easily seen. There are several ways to repair dents: The artisan way of meticulously using a pick hammer and file, working the highs and lows until you reach that perfect piece of metal; or using fillers--lead or plastic. We sometimes use the hammer and file, never lead, although we have tried it. Our compliments to those who do use it. We have found that plastic fillers work fine when they are correctly used. They should not exceed 1/8" in thickness in their finished form, and should be used over good primed metal. Filling rust holes and painting over them will result in bubbles in the paint at the repair sight in about 6 months. The only exception to this that we have found, is to clean the rusted area, painting on POR 15 (rust preventative), priming while it is still tacky, then painting. We did this for a test on a panel 5 years ago, and it still looks good!
One of the largest dents was on the driver's door. It had been hammered out using a dolly which had left a concave edge. With a polyester filler (which is less likely to shrink into the sand scratches), we covered over the dent, going beyond the damaged area to allow the filler to feather back into the straight metal and not leave a ring where the dent was filled. We always stay with the same product throughout the project, usually PPG products obtained from our local distributor, Auto Color here in Chattanooga. We have found that getting new mixing formulas for vintage car colors from a manufacturer's archives sometimes does not result in a match. That's because some of the formulas were made for older products and don't carry over to the newer products in the same way. That's when you need a distributor with a good eye for color, who will make the necessary "tweaks" to give you just the color you want.
When we mix our filler, we use glass or a mixing board available at automotive paint supply stores. We never use cardboard because is has oils in it and can cause bonding problems with the filler. We apply the filler in long strokes in one direction only. This bonds to the metal better than short strokes or swirls. After approximately 10 minutes more or less, depending on the weather conditions, we check the filler. If it has set up, we level it using a file, then go over the entire area with a 36" sanding board and 36 grit paper, sanding in a crosshatch pattern at 45 degree angles. This creates a diamond shaped pattern, taking out most of the high and lows. We continue our crosshatch sanding, changing to 50-80 grit paper, until we feel the area is correctly shaped, then apply a couple of coats of primer.
See you next month as we continue our body work on this '53 Riviera. Keep 'em driving!