With the majority of the primary metalwork completed on the Project Potvin '29 roadster, it's time to move on to the front sheetmetal. The body is bolted firmly in place and the doors are hung and gapped nicely, so the time has come to fabricate the track nose, grille, and then the hood. The plan calls for fabricating the nose and hood as two separate units from aluminum and mounting them to an inner support structure off the frame. Dzus buttons will secure the tin and facilitate easy removal in case of engine fire, violent blower explosions, or just to check the fluids. Hopefully the first two will never happen and the last will probably happen once or twice, but perhaps just as rarely.
The track nose is the first item on the list. Since the shape of the hood is not only dictated by the shape of the cowl, but also the shape of the nose, this needs to be fabricated and installed before the hood can be sorted out. But before any aluminum can be manipulated into shape, a foundation needs to be laid out in which to form the contoured nose. For this application, the foundation will be in the shape of a wooden buck, formed from 3/4-inch sanded plywood. This buck will act as a pattern to which each aluminum piece can be compared while fabricating the actual track nose.
With the car set up at ride...
With the car set up at ride height, a wire skeleton is fabricated from some 3/8-inch tubing to act as a visual aid in creating the front-end shape.
While a buck can be built any number of ways, this seemed the most logical means to an end, giving us the ability to fine-tune the buck as the metal was shaped. It's also lightweight and easy to work with and will be plenty sturdy to support the nosepiece while it's being fabricated. One thing to keep in mind is that the metal is not formed around the buck. Each piece will be shaped using various tools, machines, and techniques and checked regularly against the buck for fitment. A tiny bit of forming may be necessary with the piece in place on the buck, but it is by no means designed as a dolly of any sort.
The first step in fabricating a buck is to outline the desired shape of what it is that is going to be built. For this case, the hood line, profile, and contour of the nose itself needed to be determined. To get the correct shape, 3/8-inch tubing was used to mimic the shape of the cowl, but scaled to match the taper from the cowl to the front end of the car. Next, the slope of the cowl top determines the hood centerline. This provides the width and height of the backside of the track nose. For the profile of the nose itself, a piece of plywood was placed against the front crossmember and a rough profile was sketched out until aesthetically pleasing when viewed from the side. Another piece of tubing was bent to match the profile of the nose and the three sections-the backside shape, side profile, and hood centerlin-were all attached to form a backbone for the shape of the front end. Once pleased with the shape of the mockup tubing skeleton, the profiles can be traced onto the 3/4-inch plywood that will form the foundation of the wood buck.
While the fabrication of a wooden buck is not necessary every time a panel is fabricated, it makes the fabrication process that much easier and more precise for jobs where there are compound curves and necessary parameters to be met. Building a buck that carefully matches the shape and dimensions necessary of the end product ensures that all that time spent fabricating will pay off.
With that said, it's time to make some dust, sawdust that is, and knock out a wooden buck for the old '29. Tune in next time as we head over to the Roadster Shop where Sam Waltermire will be hammering out the aluminum track nose from our buck.
The first step in creating...
The first step in creating the buck is to trace the shape created from the visual aid.
The back of the buck is traced...
The back of the buck is traced from the portion of the tubing frame that was bent to match the contour of the cowl.
To keep the vertical sidepiece...
To keep the vertical sidepiece nice and perpendicular to the backside, a couple of pieces of angle iron are clamped in place.
Here's a couple of tools that...
Here's a couple of tools that came in handy when assembling the buck.
When it comes to fabricating...
When it comes to fabricating the stringers for the wooden buck, there is no formula. For this buck, a basic curve was laid out on each piece and cut accordingly.
Here's the four-side stringers...
Here's the four-side stringers mocked up in place on the buck.
Once all eight stringers are...
Once all eight stringers are cut out, it's time to shape them to the buck.
Since the buck and the stringers...
Since the buck and the stringers don't serve a load-bearing function, each stringer was drilled out with a hole-saw to make the buck lighter and easier to work with.
From this angle, it's easier...
From this angle, it's easier to see how the shape of each pair of stringers was kept identical.
The first two stringers have...
The first two stringers have been roughed into shape and are in place.
With the buck complete, it's...
With the buck complete, it's mocked up to the car, and tapelines are drawn to mimic the hood lines.
Here's an example of a wooden...
Here's an example of a wooden buck seen at Marcel's Custom Metal Shaping for a streamliner the crew built.
While the stringers are attached...
While the stringers are attached to the back and sidepieces of the buck, it's important that they don't pull the sidepiece toward one side.
Marcel works a piece of steel...
Marcel works a piece of steel to be used on a steel buck that he's crafted.
Building the wood buck for...
Building the wood buck for the entire care was the first thing on the list when Marcel built the Ridler-winning body for Ken Reister's '36 roadster.
Here is another example of...
Here is another example of a wooden buck in use.