So with the say early 60 era unibody's, anybody have experience chopping a roof? Is it a task feasible for the DIYI body novice that has welding skills? Seems to me biggest hurdle is the glass solution. Seems a lot of chopping started in old hot rods with flat glass cars, but all the multi curved window stuff seem to be tougher hurdle. Are the A pillars always tilted back further? Seems if one does not, and rear roof is also not tilted the roof skin needs to be split and a filler added to make for the wider span. Tilting the pillars makes the glass solution a lot tougher vs say just cutting it back. Is typical laminated front windshield glass "cuttable"? Or is lexan Margard in the picture?

Well lexan is no way to do windshield in a car you intend to drive frequently other than a race car.

Just lengthening the roof will look like crap. The pillars usually need to be tilted back for the right look. As well, they need to be tilted in OR the roof needs to be widened.

And then its not just a matter of cutting the existing glass (if it can be cut) because the curvatures may no longer be correct.

I think this is something you want to do a LOT of research on and have the answers before you make your first cut.

FWIW, I was at Carlisle a couple years back and there was an old Caddy there with a drop dead chop job. The car was for sale for $2500. and was easily worth that. The problem ... no glass !!

Keep in mind that the side glass will also be an issue.

One thing you notice reading about any chop job is they generally mention the windsheild being out of a something or other. In other words, they found a windshield that looked right for the job and they proceeded to build around it.

Yes you have a better understanding of the complexities then I do. Side window on the likely candidate car is all flat side glass, so that can be resolved. would like to lean the pillars for looks and aero, but only if I can come up with a glass solution. You are right about hearing of donor front glass solutions for chopping, makes a lot sense I guess and I'll explore that. How about a rear window lexan solution, car will not be DD, but will be on the street.

from what I dealt with on the stock car (A body) I would highly suggest haveing subframe connectors installed first (which is a good plan to have them in any app).

How about Optic Armor? Supposedly a higher grade of material than lexan. Not DOT certified but for a weekend type car I would think it would be fine. Lot of street/strip guys use them as windshields.
http://www.opticarmorwindows.com/Why-Optic-Armor.asp

Remember, when you drop the roof your side windows will have to lean in more so you will have to also modify your regulators to re-aim the glass.

another solution used on windshields and backlites, is to "sink" the [openings] bottoms into the cowl and dutchman panels, then use the factory trim [modified if necessary] to "hide" the sinking. this allows the use of factory glass with no modifications. during the chopping process, much studying needs done to see if this will work. lots of early to mid 60's cars done this way with excellent results.

A buddy of mine has chopped a few tops on '50 cars. He always sections tops in quarters or more to achieve the right look. Its not just cutting at pillars.

Flat glass used in the doors and qtr glass... Workable to cut down vs the NON cuttable CURVED tempered glass of cars after that era..

Yes you can cut Laminated WS's, but it gets pretty spendy when you make mistakes or the score flares off into the part you want to keep..

Remember Australia uses ( at least they used to) Tempered glass in there WS's....... NON cuttable.....

All good useful responses here. Thanks

Almost wonder if getting a donor rust bucket low dollar car alongside to practice on/test, work out the details, and to get the right look is something to consider.

I'm not a big fan of doing things twice. I'd much rather spend extra time planning than wasting effort, money and materials "trying" things. How many donor cars are you willing to go through if each attempt fails ?!?!

A wise man once said "if I have 3 hours to chop down a tree I'd rather spend two hours sharpening my axe"

You are right, but when one is going for a certain "look", it reminds me why they put the eraser on the pencil. And to be specific, if I need more then one "template" test car, I picked the wrong project, and not like that has ever happened before with me .

Got a Photoshop of the proposed chop?

Not yet yet, currently wrapping up the CF trunk/wing, and revised hood. The issue is the roof design/height is really screwing with the rear pedestal mounted wing trim, besides other things, and a roof chop solves a lot of issues.

Researching true custom glass manufacturers, seems like it would take care of a lot of issues, but cost is likely to be the deal breaker. Or just have a supply of lexan tear off winshields sitting on the shelf.

a book i would highly recommend you peruse before starting your adventure is "how to chop tops" by [the late] tex smith. this was published in 1990, and i don't have any idea if you can find a copy [besides the one i have], but it describes how to do many types of chops on many types of cars, including ones in the 60's. also, there is one chapter on cutting glass, which also explains the "sinking" of the front and rear glass i was talking about. it also has chapters on proper proportioning,measuring, garnish moldings, and a chapter on chopping a 60 dodge that may be of interest to you. also, a couple of guys you may want to contact before you start are : gene winfield, and brent wandervort [of fatman fabrications]. both of these guys have tons of experience chopping tops of all variations, and are easy to talk to. i went to a seminar at an NSRA event many years ago, sponsored by winfield, and it was VERY informative.

https://www.amazon.com/How-Chop-Tops-Hot-Rod/dp/1878772074

Kind of pricey for that type of book but this was the first hit on Google. I'm sure you could find it for half that price if you spend a few more minutes than I did.

Thanks guys, I will look into those sources. One detail I did not mention, I'm wanting to do a rather custom cage, and taking the roof off, would be ideal, and if the roof is already off, then......

There are a ton of tutorials on chopping on the net. Plenty of documented chops so that a 25+ year old book would be a limited resource.
Other points to ponder include:

Safety/strength, since a unibody by definition doesn't have a frame, you must consider being able to fully weld all layers cut. This means you may want to 'skin' the roof, chop the underlying structure, then reskin. This requires much more planning, since you can't see the end product and adjust during the chop. Many here will scoff about a cruise night or occasional use car being a safety concern, especially when you have seen sedans and coupes turned into roadsters, but if you are going to put in the effort, you do want it to last.

Glass as mentioned. Either slide the glass (and framework) down, tilt it, swap it or cut it. Metal is easier to adjust than the glass. This is another reason Caddy had straight side glass for so long. The professional car coachbuilders (ambulance, hearse, limo) wanted to be able to change the rooflines with minimal unique curved glass. The windshields were taller curved glass that was shared between the styles. The side glass was easier to make different as needed.

Swapping on another roof. The 57 Ford Ranchero and Fairlane had a 2" shorter roof than the standard sedan. There have been a few 50s and 60s cars with swapped tops in the show field over the past decade.
Here is a 64 Rivera with a 72 (?) Rivera roof. You REALLY have to plan this out, for looks and strength! Some of these look way off.

another

Most everyone has forgotten one of the first sentences in your question.
It reads: " Is it a task feasible for the DIYI body novice that has welding skills?"

The answer is NO! It is far beyond most professional bodymen (as if you could find one of those).

Most of the early car chops had at least one pillar vertical. That made the usually back pillar easy, relatively speaking. The windshield usually had some rake and that was sometimes made up for by stretching the roof.

Windshields in early cars were flat plane and it wasn't that hard to get them made. I must have missed the part about using another car's windshield. Maybe I was just fixated on real hotrods, '48 and older.

On a later model car where the A pillar tilts back, the C pillar tilts forward, and the roof has a significant tumblehome, it becomes more than 10 times harder.

Don't do it.

R.

I partially disagree with this. I think ultimately the poster is going to have to decide if it's a task he is capable of. I've seen professional body men that can get a panel laser straight but can't fabricate anything. I've also seen fabricators that can make panels from scratch but suck at the finish work. So ultimately it's a decision the poster has to come to if its in his realm of talent.