Door Jambs (cont.)
Ok, back to the lower front door jamb. It’s the part of the door jamb that seals off and thus will be attached to the donor C4 Corvette door posts. The C4 used a Fiber Reinforced Plastic (FRP) piece there and I’ll use it as a buck if you will to guide the metal shaping. This picture shows the C4 FRP piece and the hammer forms I created using the FRP buck as a guide.
A tooling side note: For a lot of the metal shaping I show here, I use an air power hammer. Kent White (a metal shaping virtuoso) of TM Technologies developed and sells this very versatile metal shaping machine. It uses specially converted pneumatic rivet setting motors of various sizes for the power bit and many different die sets for various stretching, shrinking, and planishing operations. For my power hammer, I chose to build the frame, stand and tool basket myself and bought all specialized pieces from TM Tech. I do have an English wheel and other metal shaping hand tools but the air power hammer is my “goto tool” for most metal shaping work.
Ok, back to the build. The curved channel piece was formed by first creating a straight channel by bending 90 degree legs on a break and then stretching the metal in the legs to curve it. I used linear stretching dies in the air power hammer to do this. The rest of the shapes in this area took some very precise templating and bends for the necessary fit. Here it is in the as welded state.
Here it is after metal finishing and in situ.
Another side note. Given the door jambs for the left and right sides of the car are mirror images of one another, I’m building out two sets of door jambs here but only showing pictures for one of them. I tend to build out sections on the passenger side first and then repeat the process for the drivers side. My reasoning for this is that once the car is finished, I’ll see the drivers side the vast majority of the time so I want it to be the better one. Since I’m figuring out how to build these pieces on the fly, my “first attempt” goes on the passenger side and the better second attempt goes on the drivers side.
Ok, back to the build. I’ve found out the time to form a piece of sheet metal into the desired shape is only loosely related to its size. In this case, I have a fairly small sized piece but with some complicated bends/shape so it took a couple of days to make. Of course making the second one will go much faster now that I know how to do it. To make this piece, I had to make 2 sets of hammer forms, anneal the metal 4 separate times and do the bends with a flow forming tool.
Here’s the first hammer form with the first bend already made. The TM Tech flow forming tool (sitting on the workbench) is a hand-held pneumatic rivet motor with a special tool holder and plastic forming die. The forming die flows the metal over the hammer form without leaving tool marks in it. The second hammer form uses half of the first hammer form and enabled me to put a curved “z “ bend into the metal. Here’s the metal ready for the 3rd annealing prior to the next bend.
And the 3rd bend, a simple 90 degree bend, now flow formed in.
Here’s the piece in situ after the last bends are completed.
Now you’re probably asking, “Why were all the complicated bends required?” In order to use the rubber weather stripping from the C4 Corvette, I had to pretty much duplicate how it was done for that car, but without the luxury of having large presses to pressure form the complicated shapes.
Here it is with a rubber windlass in place which is just part of that nice factory designed weather stripping.
Given the complicated process to make this piece, I think I’ll make the related one for the drivers side door jamb before moving forward on the passenger side door jamb.