i have just recently acquired one of the revell kits which i plan to build at a later date but since chopping the top will be necessary anyhow i am pulling it out of the box to show my technique.
this is the kit i am starting with
stock body profile
i plan to eliminate the stock hinges so for the chop process i will use the upper hinge as a guide. the goal here is to keep as much of the window and door detail as possible so there will be less filler work later.
first thing i do is to map out where i want to make my cut lines, some people use 1/8 striping tape to get their lines, i prefer to do things by eye as i can make adjustments where necessary.
side view of cut lines
the rear cutline does not go straight across, the reason for this is that i want to keep the rear window looking as uniform as possible without destroying the lower lip of it in the process.
the first cuts i make are the rear vertical cuts where it steps for the rear window. i do this using the scribing method with the backside of a number 11 hobby blade. taking my time to make the cuts as straight as possible will ensure less filler work later.
next i move on to the front a pillars, using a razor saw and cutting on the uppermost line first. it is far easier to make the second cut if it is attached to the larger body than it would be if you left it on the smaller roof section once detached.
i then cut through the rear pillars the same way until things look like this
once you make it all the way through on the top line you will have removed the actual roof from the car like this
next we will take care of the step in the rear window, the upper line on the side of the body turned into the lower line on the rear window area. so now we use our razor saw to carefully cut to the vertical lines we had already cut with our hobby knife earlier.
once the body side is done we move to the roof side and trim out the step so things fit together nicely
once you have the steps trimmed out you can take the roof and set it on a sheet of sandpaper on a flat surface, using a figure 8 motion i square up all the edges to make sure everything is true
this is close to the fit you want to see once the notches are done and the mating edges are sanded true
now if you look close, when you line up the rear panel lines
the front no longer will line up properly
this means we have to make another cut to rectify the problem
i make this cut about 1/2 inch back from the front of the roof, that gives me plenty of area for filling and sanding if i need it later
now begins te process of reattaching the roof to the body, i start by bolstering the rear joint areas with thin strip styrene, this will give the joints a larger gluing surface area allowing a better, stronger bond.
using a clothespin to hold the strip in place inside the body, i flow some liquid cement into the joint and let it dry
after the bolsters are installed you can glue the rear half of the roof in place, notice here on the rear of the door window opening, you can see a small bit if the thin styrene i am using for bolster material. it will make no difference and will be cleaned up in the next couple steps.
2 ways you can glue the front roof back on, you can add a thin shim along the entire roofline to keep the front window area at the stock angle. or you can lean back the window slightly as i have here as i prefer the look.
line up the front door seam lines and glue the top in place
this is what the new chop looks like so far from the front
i always prefer to use styrene as a filler over putty whenever i can, so i use the same thin styrene strips cut down in little pieces to fill any gaps and bond them all together with a drop of liquid cement. ( make sure most of your "shims" are on the outer curved edges, mush easier to trim and finish on the outside surface than they are if left long on the inside.
i did the same for a couple small gaps i had at the rear
once the glue dried, i used a file to remove the excess plastic on the outside of the vehicle
that is the kind of fit i want, thats without using any body filler.
i next grab my putty and apply it to areas i want to smooth out a bit more like the roofline and 2 small areas at the back
99% of that filler will end up sanded off by the time i am done but its nothing to worry about.
later when i am ready to start working on this actual build i will get into priming and final sanding but i have accomplished what i wanted to here.
we have kept the details we wanted and lowered the lid.
2 repeat shots for comparison