Back To School
Ken Sakamoto, with over 30 years of metalworking experience, operates Sunchaser Tools and the Sunchaser School of Metalwork. You'll find hobbyists to experienced bodymen at the three-day classes, though the majority are metalwork novices. The class we took included all ages and skill levels, from Phoenix, Arizona's Billy Branch who was four days away from retirement, to 20-year-old Nikki Taylor, Ken's first female student, who was keen to learn how to repair her own '56 Chevy truck.
The classes start with a basic theory lecture, explaining in simple terms the composition of sheetmetal and why it expands, shrinks, or stretches when hit or heated. The lecture is followed by some simple tool preparation techniques. This is the first time some students have ever used a grinder. Another lecture on correct use of hammers and dollies-how to hold and swing the hammer, which dolly to use, how to raise a dent by hammering from the topside and why it "rises"-follows before students are presented with a 16-inch square piece of sheetmetal and invited to hit it with a ball-peen hammer and bend the corners over. They then learn how to return their panels to as-new condition. The first day ends with Ken demonstrating how to remove large dents from a Model A fender, and how to use his patented Shrinking Disk-or "the big eraser" as he refers to it-to metal-finish the fender to a point where it requires no filler before primer.
The first practical sheetmetal...
The first practical sheetmetal task for the class is to bend and hammer a flat sheet and then attempt to return it to its original shape.
This is the tool many students may have previously seen Ken demonstrate at shows, and its promise of metal-finishing bodywork with relative ease is what persuades many to enroll in the class. Having now had the chance to use the disk, I can confirm that it does work! Hammer and dolly work is required to bring the panel up to where most would then add filler, but the disk heats the high spots, which then shrink when cooled with a wet rag. Added bonuses are that no metal is removed and the process is much quicker than the traditional method of using an oxyacetylene torch followed by hammer and dolly work to shrink sheetmetal.
Day two sees some students using the Shrinking Disk to finish their flat practice panels, while others straighten project panels they brought from home. There are additional lectures on more complicated dent removal, such as on compound curved panels, with the third day devoted to the students switching day two's roles, and again more lectures-this time on dolly, spoon, and sanding block selection, plus basic gas welding techniques.
Although Ken is in the business of selling tools, he takes great pains not to give students the "hard sell," though inevitably he will recommend certain tools. The Friction System, for instance, not only includes Ken's self-designed Shrinking Disk, but backing pads, Strip-It discs, and, importantly, an instructional video. Though it is probably most beneficial to novices, the three-day course is bound to teach even the most jaded bodyman something new, and the Shrinking Disk is a worthwhile addition to the toolbox of anyone who would rather not use plastic body filler by the bucket load!
 We took along a pretty beat...  We took along a pretty beat up '59 Chevy truck fender we had laying around. Here, the damaged area is ground back to bare metal, sprayed with blue dye and block-sanded to reveal the low spots. |  It's important that the backside...  It's important that the backside of the panel is cleaned of old underseal and paint. We used a Strip-It Disc on a Makita 5-inch sander. |  Once the repair was pretty...  Once the repair was pretty straight, the Shrinking Disk was applied to the panel. |
 Once finished with the disk,...  Once finished with the disk, the repair is hit with 100-grit on a grinder. |  After some hammer and dolly...  After some hammer and dolly work, followed by more dye and sanding, the damage was reduced to this. This step was repeated once more before firing up the grinder. |  We were pleased with this...  We were pleased with this result, but Ken said it could be better, and offered to show us just how good the Shrinking Disk could be. |
 The final result! Any imperfections...  The final result! Any imperfections left are between 1/32 and 1/100 of an inch. Ready for primer! |  After each period with the...  After each period with the disk, the panel has to be cooled by dragging a cold, wet rag over the work, leaving 6-second intervals between passes. Steam like this means it's been heated enough, definitely more than we'd been doing. | |