Back in the May issue we cut the roof off a perfectly good Shoebox Ford to illustrate how to transform a sedate, little coupe into a mean-lookin' kustom kemp. We only got as far as lowering the actual lid, and in last month's edition metal master Scott Guildner demonstrated how to fit the freshly chopped doors and fabricate all the little trim pieces necessary to make the windows look right. Now, we're finally going to finish things off.
What you see laid out before you is, without question, the most difficult part of the chopping process. Hacking off chunks of roof with a Sawzall and cutting window frames is easy; the true trick to chopping a top is in how the back window is finished. While there is slightly more fabrication required in this final step than the rest of the project has required, don't be afraid...simply take things one step at a time and work with a cautious hand. According to Guildner many backyard bodymen have a tendency to rush through this last step, which can result in a badly botched roofline that looks either far too slanted or lumpier than grandma's gravy. You may notice that we make use of several cardboard patterns in this stage of the chop, and we do so for good reason. Now that the roof is in place and the final finishing panels need to be fabricated, paper products are a lot cheaper than metal and easier to work with, to boot. Try different shapes and sizes, and if something doesn't work, simply throw it in the round file and start over. Once your desired panel has been successfully fabricated out of processed tree guts, transfer the pattern to steel and start welding! Remember to tack-weld only, as final fit and finish can take a while and laying down long sections of weld can warp and wave panels that aren't fully tacked to the car. Now follow along as we complete the chop process on what is quickly becoming a tasty traditional treat, and look for a future article that will illustrate how to cut down stock glass for your freshly chopped ride.
After grinding off all the...
After grinding off all the old paint, Scott Guildner lays the back window frame in the hole at an angle to approximate the slope of the new rear roofline. Patch panels will be made to flush everything in, and this method allows the stock rear window (which is difficult to cut) to be retained.
Run a piece of masking tape...
Run a piece of masking tape lengthwise down the centerline of the car from the roof to the trunk lid, and position the rear window frame so the top and bottom lip of the frame touch the tape. This will ensure a properly sloped rear window and smooth roofline.
Next, Scott uses a plasma...
Next, Scott uses a plasma cutter (a Sawzall will work) to make 10-inch-long cuts at approximately one-third and two-thirds the width of the roof, which will allow the metal to spread and accept the newly repositioned back window. Then, clamp the roof panels to the extra meat on the back window and spot-weld everything together.
Use a piece of butcher paper...
Use a piece of butcher paper or thin cardboard to make patterns of patch panels that will fill the gap between the roof and the back window. Don't forget that the larger the piece, the more compound curves you'll have to deal with as it wraps around the window.
Once the shape is achieved...
Once the shape is achieved in cardboard, Scott lays the pattern flat on a piece of aluminized steel (which is more pliable for metal working) and traces out the shape.
The flat panel won't fit as...
The flat panel won't fit as it sits, so Scott recommends a few passes in an English wheel to obtain the compound curve necessary to wrap the piece around the roofline, but if you can't manage to find someone with a wheel, body hammers and bucks work almost as well.
Perfect! The new patch fits...
Perfect! The new patch fits like a glove and can be tack-welded on.
Next, a strip needs to be...
Next, a strip needs to be mocked up and measured to fill the gap below the back window. This piece is primarily flat, so use cardboard to figure out the shape, then transfer it onto metal and tack everything into place.
Voila! With all of our patches...
Voila! With all of our patches and filler pieces tacked in place the chopped roofline is starting to look whole again.
Little details like door corners...
Little details like door corners and window shapes make a big difference in the overall quality of a chop. Everything about these cars should be smooth and round, flowing easily from one end of the roofline to the other. Because of this, the squared-off door corners drove Scott nuts, so he decided to fix 'em.
Use a roll of masking tape...
Use a roll of masking tape and felt pen to trace a round curve onto the door, then cut carefully with a cutoff wheel.
Once again, Scott busted out...
Once again, Scott busted out the cardboard to mock up a patch piece that will follow the now-radiused door corner.
Weld the trim tab on and finish-grind...
Weld the trim tab on and finish-grind the gap with a hand-held dremmel. Notice how much better this looks?
All the final welding should...
All the final welding should be done with a gas torch (as opposed to a wire welder) and a hammer, in a process called "Hammer Welding." This involves holding a hammer behind the panel being soldered and using the heat as well as the surface of the hammer head to shape the metal and prevent warping as it is stitched up.
What do ya know--it came out...
What do ya know--it came out pretty damn good! With the metalwork done all that's left is to grind the welds smooth, throw on a light skim coat of Bondo, and spray everything down with black primer. Stay tuned to a future issue where we'll demonstrate how to cut down glass for a chopped car.