A better method of blasting sheetmetal involves using plastic media. The small plastic particles usually have sharp edges that are very effective at stripping paint, yet the plastic won't create heat when it contacts the steel surface, so warpage isn't an issue. Typically, a car body will be completely dismantled prior to blasting, though it isn't absolutely necessary, as it is with dipping. Glass and other trim can be covered for media-blasting. Unfortunately, this media does end up in virtually inaccessible places, so this is certainly a concern.
Another emerging trend in body blasting is the use of baking soda as the media. The baking soda is also effective at stripping when applied under pressure, though it is pressurized with water rather than air. This process, considered wet pressure blasting, does not create dust and is not harmful to glass and trim. As a bonus, disposing of the baking soda can be as simple as washing it down the sewer, as some cities actually appreciate the addition of the baking soda to sewage since it will neutralize acids. Like media-blasting, baking soda blasting is a professional service, not a DIY deal.
StraighteningOnce you've gotten your body down to bare steel, you'll be able to see all of its flaws. Even nice examples of 20-year-old cars will have some dents, dings, and possibly rust. Some of the minor imperfections will be harder to spot, requiring an educated feel to locate, usually by rubbing the open hand back and forth along a panel. Fixing dents and rust does require varying degrees of skill, depending on how much work is required, but it is possible for the novice to tackle some of this, even if the pros have to be recruited to finish up. The key is not creating more work in the process.
Panel ReplacementObviously the simplest way to deal with damaged body panels is to replace them. For older classics, this may mean scrounging the swap meets or the Internet, though the list of reproduction sheetmetal for muscle-era cars is growing steadily. It comes down to determining whether to replace or repair, which should probably be based on how much work is required to repair, and how that compares with the cost of replacement. Remember also that while fenders and doors are relatively easy bolt-on items, quarter-panels and rocker panels are not, and must be cut and welded (see "Reconstructive Surgery," page 32), which basically requires professional installation and significantly increases the cost of replacement.
Rust RepairCars built during the '60s and '70s were notorious for rotting, even when based in mild climates. Much of the problem was due to poor drainage and leaky body and glass seals, so rust can even plague cars that have never seen snow. Short of replacing rusted panels, proper rust repair mandates welding, though a 110-volt MIG-welder is usually sufficient for sheetmetal work. Some small rot holes can be patched with pieces of sheetmetal stock, while larger holes may be easier dealt with using specifically stamped patch panels. Patching with sheet stock is pretty straightforward: Trim out the rusted section, cut a piece of new steel to match it, patch it in with small welds, spacing them out to minimize the concentration of heat, and continue around the panel until there are no gaps between the patch and the panel. Then grind down the welds and smooth the repair with filler. The better you are at this, the less filler you'll need. Stamped patch panels will require more specific trimming of the rusted section and careful alignment. If you have little or no experience but do have access to welding equipment, practice on junk panels first. If you think it's completely over your head, talk with a professional for an estimate.