Performance & Hotrod Business - February '15

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February 2015 n Performance & Hotrod Business n 45 tion to a ceramic coating's ability to lower under-hood temperatures and to improve heat management for header or exhaust manifold applications, this treatment pro- vides an excellent appearance-improver and is a vastly superior approach as opposed to applying a conventional heat paint. Tubular headers, (and some aftermarket cast manifolds), are available already coated from the manufacturer, usually in either a high-luster aluminum or black finish. For those headers (or manifolds) that are pres- ently bare or painted, you can ship the items to a coating shop where the surfaces will be prepped and coated in your choice of color. Different shops offer different color choices, so take the time to check out their offerings and let the customer make the selection. Choices will vary from white, black, bronze, copper, red, blue, green, alu- minum and more, with finishes including satin or gloss. Ceramic high-heat exhaust coating services are offered by firms such as Jet-Hot, Cerakote, Polydyn, Swain Tech Coatings and others. (Note: While other shops offer color choices, Swain's coatings are intended strictly for function and feature a white/ frosty appearance). Generally, turnaround times for header coatings run anywhere from one to three weeks, depending on seasonal workloads. Aluminum or Stainless Steel Polishing If you desire a glossier, shinier appear- ance on an aluminum or stainless steel component, without plans to apply any type of coating, the options include hand- polishing using fine abrasives, polishing compounds and plenty of muscle-numb- ing elbow grease, polishing using a buff- ing wheel and polishing rouge, vibratory polishing or electropolishing. Vibratory polishing involves immers- ing the item in a slurry of abrasive stones that rub against the material surfaces in a vibrating machine. The level of polish is dictated by the type, shape and size of the stones, (these vary widely). Depending on the item at hand, vibratory polishing may or may not achieve the level of finish that you're after. Electropolishing, also known as elec- trochemical polishing, is a process that removes a minute amount of material from a metallic work piece, used to polish and deburr metal parts. This process also removes any discoloration on the surface that was caused by heat treating and/or oxidation. Basically, it's an easy alternative to abrasive polishing. Electropolishing may or may not pro- vide the level of polish that you desire. If you want to enhance the finish in terms of gloss, vibratory or electropolishing will likely provide acceptable results. If, on the other hand, you want the highest level of polish possible, you'll likely need to do this with buffing/polish- ing compounds and plenty of time. You can save some time by first having the item electropolished or vibratory polished, fol- lowing up with hand- or machine-buffing. Glass Bead Blasting If a satin sheen is desired on an alumi- num surface, (for instance on an intake manifold), and if you don't plan to apply any type of coating, treating the surface via glass bead blasting is a common practice in order to obtain a fresh, uniform appear- ance. However, if appearance is the goal, it's imperative that the glass bead media, (or whatever blast media you choose), is fresh and clean. If the media has been used for a while for general cleaning purposes, chances are high that it's contaminated with particles of old paint, carbon, grease or other debris. If you blast the surface with dirty media, you'll end up with a mottled appearance as the con- taminants are imbedded into the surface. If you plan to blast in order to obtain a clean, fresh appearance, you need to empty the blast cabinet, clean thoroughly and add a fresh load of media into the hopper. Mike Mavrigian has written thou- sands of technical articles over the past 30 years for a variety of automo- tive publications, in addition to writ- ing nine automotive technical books for four different publishers. Mike also owns and operates Birchwood Automotive in Creston, Ohio, where he builds custom engines, street rods and performs vehicle restorations. Mike can be reached at 330-435-6347 or Birchwood's website is Digital Spring Tester/Measuring Combo, 66842 Spring Tester/Measuring Combo, 66841 Black Crinkle Bowtie Breather Cap, 141-614 Billet Aluminum Overflow Canister, 69528 ProformParts ProformParts NEW PARTS! Visit and sign up for a FREE 2015 Catalog!

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