It almost seems as though a shop today can’t survive without a bead blast cabinet. While a pro builder certainly can’t get by without one, affordability and efficiency have made them a piece of equipment the home enthusiast usually isn’t without either.
Our starting point was this...
Our starting point was this grungy original 409 Chevy dual quad intake; fairly typical of a speed part, factory or aftermarket, that’s been used, neglected, a little abused, and forgotten.
The first step to giving new life to any vintage part is cleaning off decades of grime and oxidation. Once the grease is cut in the parts washer or with some spray-on cleaner, nothing handles stripping better than a blast cabinet. Over the years we’ve worn out several wire wheels on the bench grinder and wire cups on a right angle grinder to remove rust and paint from parts. Now that we’ve got a blast cabinet, our time spent refurbishing parts has been cut at least in half, our ears don’t ring from running the grinder, we haven’t lost any fingerprints from wire wheels lately, and we aren’t blowing black boogers out of our nose from the stuff wire wheels throw into the air. Blast cabinets are quick, the dust is contained, and they’re always ready to go.
When it comes to blasting metal, there are as many different kinds of media as there are metals, covering everything from relatively mild crushed walnut shells to aggressive silicone carbide. For general cleaning purposes, glass beads are by far the favorite for pro and home enthusiasts alike, as glass beads will quickly strip rust and paint without damaging the base metal, particular soft aluminum pieceswhich are in no short supply on our hot rods. Well, not actually damage, but glass beads do effect the surface finish.
The heat shield needs to be...
The heat shield needs to be removed. Rivets are press-fit and can be worked out with a chisel and reused. Glass beads stuck behind it will ruin an engine.
Over the years we’ve noticed there’s a distinct difference between as-delivered cast aluminum pieces, and glass-beaded aluminum. Whether we spotted N.O.S. vintage intake manifolds from Edmunds and Edelbrock, or something like factory finned aluminum Nailhead or Corvette valve covers and OE aluminum intakes we’d see in original factory photos, there was always the same difference: the original stuff looks smooth and has a dull silver-gray color to it, while glass beaded aluminum always looks like it has a very fine texture to the surface and an unnatural white luster.
Besides the detail of done-at-home surface finish, aluminum is fairly fragile, and while factory parts will frequently need some attention, it’s the vintage speed parts that are usually in the worst shape. While factory cast pieces, like taillight buckets or dash trim, are usually in decent shape, hot rod parts have been installed and uninstalled by ham-fisted weekend mechanics or racers in a hurry since they were new, and when they haven’t been getting stripped, cracked, and broken from over-zealousness, they’ve been bounced around shop shelves and swap meets for the last 40 years. In short, their treatment has typically not been kind.
Glass-bead blasting makes...
Glass-bead blasting makes short work of grime and oxidation. It also reveals flaws such as cracks and breaks, which we found on this intake.
When it comes to aluminum parts, re-tapping threads or adding Helicoils is something most of us are capable of. The benefit of aluminum is that it’s easily weld-able, so some deft work with a TIG welder, and we’ve seen more than a few four-speed trans cases with welded ears or a blob of weld on an intake, but that’s where most people call it good. Some detail work with grinders and burrs goes a long way toward making a repair look better, but that’s about as far as most of us can take it.
Doraville, Georgia’s Lamar Walden has an impressive resume going back to the early ’60s, including being a factory-backed Pro Stock racer. Having set Pro Stock records and built record-setting engines for others over more than 40 years, he has an attention to detail that is above average, to say the least. It’s this attention to detail that has also made him an accomplished car restorer, and while you wouldn’t think to bring high-end concours-style restorations to a machine shop to have the chassis done and body panels aligned, on any given month there are ’50s and ’60s Corvettes or muscle cars in the shop being put together for judged competition.
We’ll jump ahead to show the...
We’ll jump ahead to show the difference between a glass-beaded finish, and Lamar Walden Automotive’s “reskinning” process. The passenger side of the intake is as-blasted, the driver side is “reskinned.”
Bead blasting revealed a cracked...
Bead blasting revealed a cracked mounting bolt boss, and just a little effort broke it away. Cracked temp sending holes and pipe plug bosses are also common.
Steel pipe plugs will strip...
Steel pipe plugs will strip the threads or break the intake before they’ll come out. Walden mills it away to save the internal threads. This is a ’60s Edelbrock C3B.
Temp sending unit holes and...
Temp sending unit holes and heater hose bosses are always chased and restored. If the threads are stripped, the area can be welded, drilled, and re-tapped.
To repair cracks or missing...
To repair cracks or missing pieces, the busted area is ground to good metal, and then a generous application of aluminum filler rod is TIG-welded in.
Factory gaskets are used as...
Factory gaskets are used as a pattern to recreate the contours and accurately locate holes.