It should come as no surprise that a 50-year-old truck would have some rust here and there, and some extra holes in the sheetmetal, but all things considered our '64 Chevy is in pretty good shape. That's not to say there aren't repairs that need to be made—the ravages of time, a big drill bit, and a cutting torch had all taken their toll.
While the cab was basically sound, a section of the floor on the passenger side would have to be replaced. Fortunately the necessary repairs could be accomplished with patch panels from LMC Truck. But before we tackled that chore, we opted to address some other issues. At some point a large hole had been hacked in the floor to allow the installation of a three-speed floor shifter. As the trans tunnel in this truck is not removable, we elected to fill it with a homemade patch panel. This particular repair required a panel shaped to follow the contour of the tunnel, which was done by bending the sheetmetal over a large diameter pipe. With the curve established the patch was trimmed to size and welded in place. As this repair is under the carpet, we didn't spend a lot of time dressing the welds.
As the in-cab gas tank would not be used, next on the list of holes to be plugged was the opening for the fuel filler. In this case LMC Truck provided a preformed patch that fit the hole perfectly. After removing the paint from the surrounding area, the patch was held in place with small magnets until tack welds secured it. After final welding, the area was ground smooth and the patch was almost undetectable.
Our final undertaking was filling holes in the back of the cab that had been made to mount a large spring-loaded CB antenna. In this case the three small mounting holes were countersunk then filled using our Miller MIG welder. The larger center hole required another homemade patch. Again it was held in place with a magnet, then secured with tack welds.
When filling holes in sheetmetal it may be possible to get behind the panel being repaired. In those instances where small holes are being filled, copper backup plates will allow them to be welded solid without a plug. Eastwood can supply backup plates with a handle or with magnets to hold them in place. With larger holes, patch panels can be fabricated, and in many instances stamped replacement sections are available.
Regardless of how sheetmetal repairs are made, it's important to work slowly and keep heat to a minimum by skipping around while making lots of tack welds. And keep in mind welding isn't the only form of heat that can warp sheetmetal; heavy-handed grinding can also create more than enough heat to do damage.
Patching sheetmetal is often a part of bringing a custom classic truck back to life. So far we've concentrated on plugging the manmade holes; next we battle the damage done by Mother Nature.