Convertibles-Trunk Fabrication Video Support
Tools needed: high tension hacksaw
(tension adjuster on the handle) Air chisel
(nice to have), Die grinder (giant Dremel tool) 4," or 7-9"' hand
grinder (I like the Makita 4") cutting torch,
MiG gas shielded welder (never use the flux core wire welders)
Sawzall is very nice for cutting sheet metal
lines are relief cuts that are needed to allow trunk lid to open enough. Only do
this cutting once entire trunk is laid up and in filler. New closed cell
house weather-stripping around the sealing edge will ensure watertightness.
The illustrated curved line is the neatest part of
my convertible conversion.
This is a 2" cut out of the strut tower and the strut housing. Lowering the
strut tower will allow the top to lay flat down in the top well, and make the
top flush with the trunk lid. To cut the tower, carefully measure 2" down
from the top of the tower, then torch cut at the 2" line and at the
shoulder. Keep the top part parallel when welding it back on! It helps to make a
90 degree reference line down the center of the sheetmetal so you can be assured
of a square tower when rewelding. The front strut inserts fit in the rear after
removing 2" from the tower and the housing. You may ship the housing to me
for cuffing, if local fabrication support is not available.
Do not attempt to use the pattern I sent to layout the top cavity.
You need to transfer this pattern to cardboard
All the cars in the last part of this video have the early trunk shape.
The trunk is too long for the top to lay flat. The construction video is my new,
correct way to lay up the trunk. Tape the template to the car as described, and
the top opening will be the correct dimensions. As you can see from the above
shot, the leading edge of the trunk is well In front of the strut tower. Your
trunk will be behind the tower. Cutting down the strut tower can be done
after the trunk is all done. This step is not necessary if you will not be
Installing a top. A Tonneau cover can be constructed by a upholstery shop to
protect the interior. I split the Tonneau with a zipper so the driver's side
could be open while driving. The post and Lift-A-Dot Tonneau snaps as used on
the British cars works great. Install the posts on the metal defroster panel at
the base of the windshield. I also installed snaps on the side window wipe metal
pieces. They are stainless steel, as is the window surround.
The stainless steel window surround where it meets the windshield post
must be left in place. Removing it will not allow the side windows to push in
far enough to seal. Another trick is to use a second roller to push in the
window. These rollers are spring loaded and install under the window wiper metal
(where your snaps are for the Tonneau). Install the second roller before
drilling for snaps! There is a left and right roller, make sure you order both
The trunk release I use is the entire system off a 280ZX. I weld closed
the stock hole In the hatch, then weld a plate to the trunk between the
taillights. Close the trunk, crawl In there, and position the ZX latch and
U-shaped post. Mark with a pen, then bolt everything in. This is not a lesson on
basic fabrication, only a helpful tip.
The bulkhead between the trunk and the cockpit is best made with a piece
of thin sheetmetal. Simply curve it around the perimeter, behind the strut
towers. I put a 90 degree bend at the bottom, so everything is neat looking.
Stereo buffs can use plywood instead to support big woofers.
A rear strut brace is not needed on this convertible, because the metal
you laid over the strut tower is a box section. This box section used to be the
top hoop that the dome light went in. Very rigid! trunk build doc 1 .doc
page 5 Scott Bruning (Datsun Z Convertibles) July 1996
One of the final steps is to fill In the metalworking with "Bondo".
Please bear with me as I dispel some myths about plastic filler. Old timers may
cringe, but here it goes!
The new plastic fillers are composed of space-age polymers that are very light
weight. Also, the adhesives used are very aggressive. What this means is that
you can get away with disgustingly thick fills, with no fear of cracking. I will
qualify this statement by saying that the base metal needs to be roughed up with
24-36 grit grinding, and the surface must not be able to flex. Now that I have
explained myself, go out and buy a gallon of the best filler you can find at a
professional Automotive paint store. If you spent $12, you bought the wrong
stuff. My favorite stuff is by Evercoat. Pick up a box of 80 grit
longboard paper, and a longboard sanding stick. Rough up the trunk and area with
the 36 grit, then pour on the filler. Cover the entire trunk with a thin layer.
Then sand it off with the longboard. Sounds like work? It is! But it goes a lot
faster than filling in sections. The idea is that the 18" longboard will
smooth huge areas in as minimum of time. The finished product will be smooth and
straight. As nobody makes 220 grit longboard wet/dry paper, you need to get it
razor straight now with the longboard. This is not a lesson in basic bodywork,
so I am done taking about that.