Learn How To Hammerform - Speed Bump

It's amazing what an impact small, well-detailed adornments can have on your hot rod. Walk though any car show and there will most likely be a number of cars where special attention was paid to certain areas that most people might miss. Be it a traditional bullnose on a Deuce shell, or a custom trim piece made from stainless to accent a particular body line, there are plenty of locations to which attention could be added in truly unique ways. There is even a practical portion of the mix where such ornamentation performs a specific function, such as on a dry lakes roadster designed to slice through the wind where smoothness is a major factor in the speeds it can attain. In such cases, full bellypans are often incorporated to encase the car's complete undercarriage; while on a much smaller scale, items such as a steering blister mounted on the side of a cowl (when a Sprint Car steering unit is used) make just as much of an impact to help the car cut the wind.

Back in 1954, Doane Spencer added a Schroeder steering box to his highly competitive roadster as one of many notable modifications the car would receive over time, completing it with a subtle cowl-side blister. For decades, street-driven coupes and roadsters have incorporated the use of Sprint Car steering units for both performance reasons as well as aesthetic ones. With a Schroeder steering box added to the buildup of my lovely wife Kim's '27 Ford tub by rod builder Richie Willett, it was time to pay a visit to East Coast metal master Paul Gamache of Gamache Rod & Custom in East Freetown, Massachusetts, to get a truly unique steering blister designed for the car. Being involved in metal shaping and custom fabrication work for more than 45 years, Gamache was obviously the right person to create a one-off piece for the tub that would leave quite an impression once you saw it.

Gamache informed us that there were numerous ways to craft a steering blister, allowing for the use of different materials-including aluminum, stainless steel, fiberglass, and body filler-depending on how we would like to proceed in making the piece, be it freeform or by creating a mold or a buck. For all practical purposes here, Gamache decided to work with .090 3003H14 aluminum sheet panel for strength since he decided he would hammerform the blister in a freeform style, using many old-school tools to complete the project.

After studying the cowl area of the tub, Gamache began designing various renditions of what the blister could look like using French curves and circular templates. Once a final decision was made, he used 1/8-inch aluminum welding rod to create the basic dimensional shape of the blister while ensuring plenty of clearance for the pitman arm in its fully extended form. He then created various templates from this that would be used in its construction. With the final size of the blister being 7 1/4 inches long and 2 inches deep, there were some serious considerations to be made prior to the start of the actual hammerforming. Gamache told us the selected panel would need to be free of any blemishes, such as scratches or gouges. All of these imperfections could affect the integrity of the aluminum, potentially creating a weak link to the form as it was hammered out. Such a weak link could result in a tear once the stretching commenced, so to alleviate any potential problems, Gamache worked with his dual-action DA grinder topped with 180-grit to clean up the surface prior to the next step of annealing the metal. With the tremendous amount of force that would be exerted on the metal, Gamache advised us to use forged and not cast clamps when the forms are finally clamped down into place, as they will not fail to hold the metal in place when they are fully clamped tight.

When the completed blister is removed from its form, a decision needs to be made as to how it will be trimmed down. There are two schools of thought here, depending on if you would like a more mechanical feel to the final mounting or if you would rather have it free-floating on the cowl. For our purposes, Kim decided she would like it to free-float for a more undisturbed look, which meant a really close trim of the excess metal and the need for construction of internal mounting plates. A more mechanical look would have meant a wider mounting area cut out so a number of polished button-head bolts could encircle the piece to secure it to the cowl. While both versions are well used, it's the individual owner's vision of the completed car that comes into play at this step.

With the trimmed blister in hand, Gamache taped it to the cowl to determine its final visual mounting point, and also to establish the cutout needed for the pitman arm. This step was crucial since Gamache cut into the blister for this access. After removing the blister, the pitman arm was mounted to the steering box as Gamache marked the areas of its full extension both fore and aft, as well as determined depth needed using a caliper. At this time, he also reviewed the inside area of the cowl for mounting points to secure the blister to the cowl. Once these critical measurements were obtained, the final progress could be made on the blister.

With any custom-fabricated piece, the decisions continue as the project nears completion. Final preparation of the blister had come full circle, with all of the fabrication work fading off into the distance. Kim made the determination early on that she wanted the blister to be fully metal-finished and polished as opposed to painted, which meant Gamache had a good amount of time ahead of him with a file in hand to be followed by countless stages of sanding. Had paint been decided on, the blister would have received a light skim of body filler, which would then have been sanded smooth, primed, and made ready for paint. Regardless of how you decide to finish your blister, the results will be nothing short of breathtaking once you mount the finished piece to your cowl. Just one look at the completed piece Gamache made for Kim's tub and you have to agree it's one fine piece of jewelry that will most definitely have an impact on the car once it is completed.