Body: Fenders and Running Boards
From The Scratch-Built Hot Rod
Chapter 11: Body - Fenders and Running Boards
The design criteria for the fenders and running boards on this project are that:
- They be simple and minimal.
- They flow with the header and side exhaust design.
- They make use of existing fenders or materials if possible.
- They tie together the lines of the body and the pickup bed .
|For the front tires, the simplest treatment will be a cycle-type fender; the rear fender and running board design will be more challenging. To visualize the various alternatives, a universal trailer fender (available from online suppliers and agriculturally-related "big box" stores such as Fleet Farm and Tractor Supply Co.) and 1x2 rectangular tubing (arrows Photo 11-1 and 11-2) are used to create different layouts and designs.
The design that seemed most appealing was a very minimal hint of a running board, that will follow the lines of the intended exhaust headers and side pipes. This meant, however, that the exhaust pipes and headers would have to be completed before creating the final design for the running board and rear fender.
Headers and exhaust
Although a bit out of place in a chapter titled "Fenders and Running Boards", the headers and exhaust on this particular project will make up a major design element of the vehicle. That design element will dictate the shape and size of the running boards, and how they tie into the rear fenders. So, the headers and side exhaust system must be completed before proceeding.
The exhaust is going to run on the outside of the car along the rocker panel, so none of the typical pre-fabricated header systems will work. Instead, a Patriot brand "weld up" sprint-style roadster header kit will be used. These kits come with the head flanges and gaskets, the collector tubes, and eight individual header pipes which are bent to shape, but must be cut to length to fit each individual application.
The header tubes are first assembled in their approximate locations with the tail ends of the tubes inserted in the collector, and the tubes lashed together tightly with nylon ties (arrows) to keep them in position. The assembly is set on wood blocks to position them at the approximate height they will be when finished. The correct height and angle of the headers is critical to ensure the exhaust system will hug the body line, and that it will be below the door when it is opened. This provides a very rough mock-up, to see how the tubes will need to be cut (Photo 11-3). Next, the rear-most header pipe (arrow "A") is marked and cut to length at the head end of the pipe, so that it will fit inside the header flange while the collector and lower assembly of pipes remain in the correct position. It is best to cut the pipe a little long to begin with, and then trim the pipe down until it fits correctly.
Ford exhaust ports are rectangular rather than round, so the end of each header tube must be bent into an oblong shape to fit into the header flange. Everything must be lined up correctly before you start bending the tube end, because there is little room for error once the end of the tube has been reshaped. The pipe may need to be tilted upward or downward, forward or back, in order to get the collector tube in the correct position and allow the balance of the exhaust to follow the line of the rocker panel and to fit below the door when it is opened.
|Once the tube is cut, shaped to slip into the flange, and correctly positioned, it is tack welded to the outside of the flange in four spots. Don't overdo the tacking. The final welds for the header pipes are all done on the inside edge of the flange, not around the outside of the flange. So, the tack welds on the outside will be ground off later. After the first tube is tacked in place, move to the next header pipe and follow the same procedure. Keep moving toward the front of the engine until all the pipes are completed. Each header pipe gets more and more difficult to do, because you have less and less fudge factor available as the prior pipes are already welded in place. Each pipe must not only be cut and fitted to the flange on the head end, but must also be perfectly aligned at the collector end, so that the collector pipe will slide on and off the assembled pipes. Photo 11-4 shows the passenger side header pipes tack welded to the header flange in their final configuration.|
|Once all four pipes are tack welded at the flange, and with the collector tube solidly over the other end of the pipes to hold them in place, the header assembly is removed from the engine, and the pipes are welded to the inside of the flange. If any pipe is not snug up against the flange before welding, use the pick end of a body hammer to tap the tubing up flush against the flange hole, and then do your welding. The welds are then ground smooth (Photo 11-5).
At the collector end of the exhaust tubes, first cut and trim the pipes, if necessary, so that they all end evenly. Then, cut a rectangular piece of sheet metal to fill the space that is left in the center of the four-tube cluster (Arrow "A" in Photo 11-6). After tacking the filler piece in place, a small burr is used to grind the edges of the sheet metal to correspond with the tube openings. The fill piece is then welded solidly in place. Also, as shown at arrow "B", each set of abutting pipes must be welded together as far back along the pipe as the collector is going to slide over the tubes. This prevents any exhaust from escaping in that space.
|Next, the collector is slipped in place over the four tube ends. The collector will be welded to the tubes a bit later. It is important to note that in Photo 11-7, you can see the weld bead between the abutting pipes, which was done during the prior step. This weld helps prevent potential exhaust leaks after the collector is welded to the pipes. At this juncture, the temporary tack welds at the header flange can be ground smooth (Photo 11-8).|
|The side exhaust is also from Patriot. The pieces are shown in Photo 11-9. On the left is the muffler and 90-degree turn out. In the center is a 24" pipe extension. And, on the right is the collector from the header kit, which has been slipped off the headers so that it can be assembled with the side pipes.
The components for the side pipes are first marked so that the turn out at the end of the pipe will be in the direction desired. In this case, the turn will be pointed horizontally. The sections are then tack welded together (Photo 11-10), placed back on the headers to ensure everything is lined up properly, and then all the seams are welded and ground smooth. At this juncture, the side exhaust is still not welded to the headers at the collector pipe. This will allow a bit of final adjustment to take place as the running boards are completed.
|Fabrication of the running board frame begins with the rear brace, which will extend perpendicularly from the chassis and support the front edge of the rear fender. This brace is cut from 1x2 rectangular tubing, and has a plate welded at one end to bolt to the chassis (Photo 11-11). This rear brace is then welded to a long side brace which runs parallel with, and will be bolted to, the rocker panel of the car. This brace will extend forward to the firewall (Photo 11-12).|
|This minimal framework for the running board is temporarily clamped to the car along the rocker panel, and checked with an angle finder (arrow Photo 11-13) to ensure the brace is absolutely level. If the brace is not level, it may result in the rear fender being tilted at an odd angle.
To attach the fender to the rear brace (and allow the fender to be removable), a mounting plate consisting of a 6" piece of 2 x 3/32" flat stock is bolted to the back side of the rear brace (arrow Photo 11-14). Note that the front edge of the fender sits just at the front edge of this mounting plate. Photo 11-15 shows from the front side how the fender sits on the edge of the brace, and also shows the two bolts in the brace, which hold the mounting plate in position.
|Next, a tab consisting of a 5" piece of 1 x 3/32" flat stock is placed on the top edge of the "mounting plate" and tilted slightly forward, so that it lays flat against the inside of the fender. The tab is then tack welded to the mounting plate.
With the fender removed, Photo 11-16 shows how the "tab" extends upward from the "mounting plate". Note that the tab angles forward slightly; this corresponds with the curvature of the fender at that point.
The fender is placed back in position against the mounting plate and tab. Note in Photo 11-17 that the fender is mocked up with wooden spacers (arrow) holding it approximately 2 1/2" up off the tire. This will allow for wheel travel once the fender is permanently affixed. The "tab" is then welded to the front edge of the fender (Photo 11-18). With the fender off the car, you can see how the mounting plate is now permanently attached to the fender (Photo 11-19).
|At this point, the running board construction cannot be completed until we fabricate the remainder of the rear fender. So, we will temporarily postpone construction of the running boards, and jump into the rear fender fabrication.
As the prior photos show, a universal trailer fender (these came from Fleet Farm and cost approximately $18 each) has been used in the fabrication. However, this fender is too narrow, and does not tie in well with the pickup bed. The solution is to create a much wider fender by mating two trailer fenders side-by-side (Photo 11-20).With our one fender bolted up to the portion of the running board we just finished, a pattern can now be made for cutting the "inside" portion of the fender. The pattern is made by cutting small sections of posterboard, and positioning them snug to the pickup bed and to the curvature at the rear of the body. The various sections of posterboard are taped together to form one unified pattern. (Photo 11-21).
|Photo 11-22 shows the pattern-making from a different view. The pattern is removed, placed over the second fender so that it can be traced, and the inner fender is cut to the shape of the pattern (Photo 11-23).|
|The two fenders are then clamped together (Photo 11-24), and tack welded on the underside (Photo 11-25). Note that the mounting flange for the outside (uncut) fender is left intact (arrow). This helps strengthen the fender. The flange will not interfere with tire travel, since the tire sits totally within the width of the outside fender section.|
|Photo 11-26 shows the two blended fenders from the outside, and Photo 11-27 shows the completed fender being tested to ensure it fits snugly to the bed and body.|
|To secure the new fender to the pickup bed, a series of holes are drilled in the flanged edge of the inner fender (Photo 11-28). These holes should be spaced evenly, because the heads will show inside the pickup bed. The fender is then placed back on the car, and corresponding holes are marked and drilled in the side of the pickup bed (Photo 11-29).|
Even when bolted solidly to the bed, there is still enough flex in the side panel of the bed to allow a bit of movement in the fender's horizontal position. To ensure the fender will remain parallel with the ground, a small adjusting tab (arrow) is welded to the framework of the bed behind one of the fender mounting bolts (Photo 11-30). By attaching a magnetic angle finder to the lip of the fender (Photo 11-31) and tweaking the bolt tightness at the adjusting tab, the fender can be set and maintained in the horizontal position.
Photo 11-32 shows the two completed rear fenders.
Running board (continued)
|With the rear fenders completed, the running boards can now be finished. The original section of the running board framework is bolted back onto the car, along with the new rear fender. The side exhaust is then placed back on the header system and correctly positioned (Photo 11-33).
An outside edge for the running board is cut from 1x2 tubing so that it extends to about two inches from the end of the exhaust pipe. It is temporarily held in place with two 1x1 supports. This outside edge piece is then tack welded to the rear brace at the corner shown by the arrow (Photo 11-34).
|Next, a piece of 2"x 3/32" flat stock (arrow) is bent to match the curve of the side pipe turn out. The piece is cut to length so that it fits between the newly installed edge piece and the original main brace, which runs parallel with the rocker panel. It is then clamped in place and tack welded (Photo 11-35). Photo 11-36 shows the completed rear section of the running board framework.|
|A pattern to cover this section of the running board is made using posterboard (Photo 11-37), and sheet metal is then marked, cut and tack welded in place (Photo 11-38).|
|Photos 11-39 and 11-40 show the completed running board, and how it follows the line of the side exhaust and ties in with the rear fender.|
| The simplest and most minimal front fender is the cycle-type fender which is attached to and turns with the front wheels. A good friend and fellow rodder rummaged through his collection of fine old hot rod parts and found a set of fenders he had picked up at a swap meet and never used. These fenders had the desired look, but they were far too long. In fact, both of the final fenders came from just one original, by cutting it in half and reshaping the bobbed end (Photo 11-41).
To create mounting brackets for the fenders, 3/16" x 1" flat stock is cut and bent to conform with the shape of the underside of the fender. Two bolt holes are drilled in the flat stock and through the fender (Photo 11-42).
|The flat stock is bolted to the fender (Photo 11-43) and a second section of 3/16" flat stock is bent to pass around the edge of the fender, the tire, and the spindle, to reach the vicinity of the spindle, where it will be bolted.
This section is very lightly tacked to the flat stock bolted to the fender, and then the fender is held in place, and the long section of flat stock is adjusted so that it will clear all obstacles and be in position to be bolted to the spindle. It is then welded solid (Photo 11-44).
|A hole is drilled near the end of the mounting bracket, and the fender is again positioned over the wheel and the hole marked on the spindle. The hole is then drilled and tapped for the mounting bolt (Photo 11-45). A spacer is cut and placed behind the mounting bracket, to center the fender over the wheel. This spacer can be ground down or angled slightly to position the fender more precisely (arrow, Photo 11-46). This spacer is later welded to the bracket permanently.|
|The lower fender bracket (arrow) is fabricated in the same way (Photo 11-47), and the fender can then be bolted in place (Photo 11-48). Photo 11-49 shows another view of the cycle fender mounted in position.|
|After the car was completed and driven a few hundred miles, the mounting bracket on one side cracked at a weld, most likely due to the brackets allowing too much movement and vibration of the fenders during road travel. This is a fairly common problem with cycle fenders. To remedy the situation, vertical "ribs", made from 3/4" flat stock, were added to the back side of the brackets (Photo 11-50).|
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