It doesn't matter which manufacturer a classic truck originated from. The older it gets, the more likely it's going to have problems associated with rust burrowing holes in the body. Add 50-plus years to the equation and if the truck in question has ever been exposed to wet weather it's a guarantee there will be rust damage. Although different years and various makes all have an area that's uniquely prone to rust, all trucks are susceptible to cancerous driprails.
Age and exposure to the elements breaks down the schutz (caulking), transforming it from a flexible resilient material into one that's brittle and cracks open. The very first incursion of water permeating the schutz enters through the cracks between the roof panel and where the driprail meets; there rust begins. Similar to cancer in humans, the longer rust goes undetected or ignored, the more damage the roof is going to incur.
In the instance of Chris Travers' orange 1956 Ford F-100, the previous owner took the loving hands at home approach and put a Band-Aid over a gaping hole. This repair took place over 30 years ago, and there was no ill intent involved. He took an ROP course and gave learning bodywork his best shot. Who's to say what the 1956's roof looked like before he started. Maybe there was already a lot of rust damage and the previous owner retarded further harm, or perhaps he created an environment rich for troubles to multiply.
This is not to say packing one's own wavy bodywork with polyester body filler is such a bad thing; after all, it did take decades before Chris' 1956 had a serious pimple problem. If a person did his or her own work and was aware how much Bondo was used it's one thing, but if a shop claimed a job like this was metal-finished it would be fraud.
Chris planned originally to do the rust repair needed on the roof by himself, but an exploratory grind into its deep-rooted rustiness suggested the job would better be left to a pro. Chris packed the pre-formed three-piece driprail kit from Mid-Fifty, and drove to Chopit Kustom in Stanton, California. Thanks to Gary Chopit, along with his son Nicolas, Classic Trucks is able to show its readers how the best of the best go about repairing an extremely rusted 1956 F-100 roof. Naturally we don't assume just by following this tech everyyone will be able undertake a job like this, but no doubt there's going to be some tips that will make anyone's attempt turn out with better results.
1. Bondo 1⁄4-inch thick. Moisture enters through cracks in the driprail schutz, and left unchecked, rust spreads like cancer. The bodyline was sculpted in Bondo instead of forming metal.
2. What appear to be tiny rust bubbles in the paint are just the tip of the iceberg. Scraping the paint revealed rusted-out sheetmetal laced with Bondo, brazing rod, and patch panels.
3. The green masking tape helps to lay a straight edge to form the cut line. Note the area being cut out is well into good steel.
4. Major regrets if one fails to take this precaution: Before cutting Nick formed these braces to keep the front of the cab from springing. Note the detail added to strengthen the brace.
5. The original front driprail and the rusted area of the roof were cut from the cab. Cuts can be done with a 4-inch cutoff wheel on a die-grinder or electric body saw.