by hotrodding
Chop Top your Car
11:25 am in Body and Paint by hotrodding
Here’s a few tips to help fill your roof in:
Every time we go to a car show you will always notice any hot rod that’s had its top chopped. Now this you would believe to be done by the owner or builder of the car. Now notice I said a builder, not necessarily the owner or the person that took over the project to be completed.
Within this article I want to share with you a project that was purchased with the chop top already done, but with closer inspection the proportions were not correct, especially to the trained eye for detail. At this point the infill had not been completed so I will show the results from the previous builder and how we went about correcting it.
To add a metal roof insert first you will need a donor roof from another car which these days it is generally from the current range of cars from the wrecking yards. You will be best to remove the whole roof through the pillars where as this will keep the strength in during transportation. If you don’t, you will have the largest floppy pancake which could end up being useless if it was to buckle on you.
On the left the roof shown is from a 1948 Chev which does have more contour, whilst on the right the roof is from a mid 60’s ford station wagon which does have the flatter section. Its really your choice as to how you want it to look or maybe the donor roof came free of charge, so with these decisions it will help make the correct choice for you.
The chop top itself was done rather well though there was too much metal removed from the original roof allowing for the infill. As with most larger cars from the mid 1930’s they had more crown within the roof and it wasn’t until 1937 that the first full roof with a metal infill was stamped from the factories.
Any cars from the 60’s – 70’s should have a greater crown within its roof than the modern cars of today. You can opt to have an infill rolled from a reputable rod builder who has an English wheel, though this will be an expensive option if it is to be done well.
You may not notice this, but with the above shown chop top there has been too much metal removed from the original roof line, in particular with the rear section. This will definitely make it look too flat. One way we were able to correct this was to use an original section from a 1936 Ford parts car and graphed it back on, a lot more work but this will give better results. You can compare the two below.
This is the result from too much metal removed in the rear
Now compare the original to the chopped too far version
To chop the roof is one step but to add the metal infill is another. Either way they all have to be done right to look pleasing to the eyes, do this wrong and you will surely devalue your ride. The next photo will show you with the mid 1960’s roof we had templated up and you can see the look you would achieve if you continued this way. Once the new rear section is added this will allow you to shorten the new infill leaving the original crown to keep the factory look.
This finished would look far too flat
Have you thought how can you hold this floppy piece of tin on your roof? Well you can get the help from mates who generally charge mate rates ( a couple of beers) or there is these little helpers called weld mates.
These are great little helpers
They make welding easier.
Have you noticed in the above photo the metal tabs I have left on to help support the infill, here is another look at what I have done. These were left on the roof infill as we cut the roof to fit the hole. You can do this just to help get the exact trimming done or weld the roof in and trim them off as you go. Either way they will be of great help too.
Metal tabs to help hold the roof infill.
The finished results were completed by hammer welding and its now only requirements is a skim of body filler to fill any imperfections.
The final result
Well I hope these tips will help you make more progress on your project.
Happy Hot Rodding
This is the largest top I have chopped yet! Well I’d have to be the first to admit that this is one top that I’ve chopped I wish I didn’t have to do. Why? Because its a truck and not this truck. 
Here’s a few tips to help fill your roof in: 
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