Anyone ever chop the top on a Volkswagen?

[Mike Kucaba]

I seem to remember a thread where it was mentioned a very tricky one.

[Ace-Garageguy]

I've done a real one. Does that count?

[Skip]

Same here with Bill, did a real '61 "Gasser Style" chop. There are several schools of thought on how to do the same thing. The lower the lid is lowered the more material needed in the middle or the more slanted the "A" pillars will be.

We did a quarter cut on the roof to allow the roof pillars to remain somewhat in their "stock" angles, sections from a second or third VW roof are added to fill in the gaps. Windshield and rear window are shortened or chopped with this method. This method gives the appearance of the roof being narrowed slightly as well as a little longer; looks a little more proportional. Some of the early "Gasser Bugs" were chopped this way, while others were chopped using the stretch chop.

Another "stretch" chop cuts the roof in two to three sections, adding sections from a second roof in the gaps created by lowering the lid. The control points are the pillars as they are in any top chop, which is where cutting the roof into sections comes into play. Normally this method will allow the roof to remain visibly stock in width, the additional roof sections make it look longer though.

Then there is the angle chop method, the windshield is cut at a lower height, ending with several pie cuts almost but not completely through the rear pillars. Requires adding more angle on the A pillar, the "B" pillar is often angled forward along with the rear of the door window. Supposedly the easiest method, though not the most eye appealing as it clears an "egg shape" to the car as a whole. This is more of a "Street Custom" chop.

The other consideration might be that most of the early "Cal Look" Bugs were not chopped, they had suspensions which were as low as one could get them without resorting to air bags or narrowed beams. Of course no one was running bags on anything let alone Bugs. The basic idea of the Cal Look Bugs were first to go as fast as you could go and be streetable. Second was that the wheels were under the fenders, the rarer the wheel the better, tires were something to the effect of a 185R15 rear and 135R15 in the front, radials not bias ply. Third the exterior straight as a pin and shaved of the trim, interior hot rod styled tweed center section and leather or vinyl sides, door cards vinyl outside with tweed insert, 1 - 2 inch wide tuck and roll on the tweed. These were fast cars in their day, many ran 13's and some in the 12's or lower, normally aspirated and without nitrous oxide. I remember reading about a couple of Cal Look Bugs that ran lower E.T.'s but they were pretty much purpose built race cars. Oh and almost all of them had quiet mufflers on them, no need to advertise you were street racing especially to the law!

[Ace-Garageguy]

Excellent response from Skip, and what he says holds true for anything with a similar rear-sloping roofline that flows down into the body, ...cars like the '49 Merc or the early '50s GM fastbacks, and the '40 Ford Tudor sedan, for instance.

This '37 Ford chop illustrates the concepts...a stretch in the center of the roof forward of the B-pillars (which allows them to remain vertical), leaned back A-pillars, and a significantly re-sectioned C-pillar area.

Edited October 11, 2013 by Ace-Garageguy

[wisdonm]

A standard VW chop is very labor intensive. If you are not using rear fenders it can be a lot easier. Here is a link to a very easy chop that I did. However, it only works without rear fenders. Another side effect is that the engine bay is shortened 3 inches.

http://www.modelcarsmag.com/forums/index.php?showtopic=37434&hl=volksrod

[Mike Kucaba]

Same here with Bill, did a real '61 "Gasser Style" chop. There are several schools of thought on how to do the same thing. The lower the lid is lowered the more material needed in the middle or the more slanted the "A" pillars will be.

We did a quarter cut on the roof to allow the roof pillars to remain somewhat in their "stock" angles, sections from a second or third VW roof are added to fill in the gaps. Windshield and rear window are shortened or chopped with this method. This method gives the appearance of the roof being narrowed slightly as well as a little longer; looks a little more proportional. Some of the early "Gasser Bugs" were chopped this way, while others were chopped using the stretch chop.

Another "stretch" chop cuts the roof in two to three sections, adding sections from a second roof in the gaps created by lowering the lid. The control points are the pillars as they are in any top chop, which is where cutting the roof into sections comes into play. Normally this method will allow the roof to remain visibly stock in width, the additional roof sections make it look longer though.

Then there is the angle chop method, the windshield is cut at a lower height, ending with several pie cuts almost but not completely through the rear pillars. Requires adding more angle on the A pillar, the "B" pillar is often angled forward along with the rear of the door window. Supposedly the easiest method, though not the most eye appealing as it clears an "egg shape" to the car as a whole. This is more of a "Street Custom" chop.

The other consideration might be that most of the early "Cal Look" Bugs were not chopped, they had suspensions which were as low as one could get them without resorting to air bags or narrowed beams. Of course no one was running bags on anything let alone Bugs. The basic idea of the Cal Look Bugs were first to go as fast as you could go and be streetable. Second was that the wheels were under the fenders, the rarer the wheel the better, tires were something to the effect of a 185R15 rear and 135R15 in the front, radials not bias ply. Third the exterior straight as a pin and shaved of the trim, interior hot rod styled tweed center section and leather or vinyl sides, door cards vinyl outside with tweed insert, 1 - 2 inch wide tuck and roll on the tweed. These were fast cars in their day, many ran 13's and some in the 12's or lower, normally aspirated and without nitrous oxide. I remember reading about a couple of Cal Look Bugs that ran lower E.T.'s but they were pretty much purpose built race cars. Oh and almost all of them had quiet mufflers on them, no need to advertise you were street racing especially to the law!

Yeah! I like the stretch method.

[VW Dave]

Sadly, the stretch method often 'flattens' the roofline of a Beetle......I've heard many 1:1 customizers compare it to chopping an egg. the link below shows a very nice step-by-step done by Chris Clark Customs:

http://www.thesamba.com/vw/forum/viewtopic.php?t=345410

My own scale Volksrod has a rather flat chop, but I can only take credit for saving it from the trash bin at my buddy's house and finishing what he started.

http://public.fotki.com/vwdave/my_model_cars/volksrod/dscn3107.html

[Mike Kucaba]

I got a 1/16th VW and it's sort of a parts kit, but there are plenty of parts. I thought chop the top, put in the engine from a 959 and go salt flats!! someone already cut (neatly) a hole in the roof so it should be easy to split into 4 sections to get a neat look.

Thanks for the link, I'll check it out.

[Ace-Garageguy]

Sadly, the stretch method often 'flattens' the roofline of a Beetle......I've heard many 1:1 customizers compare it to chopping an egg.

Actually, a chop on ANY roof that has significant crown and requires lengthening of the center of the panel faces the likelihood of a flattening appearance unless the metal man doing the work is really REALLY good.

Simply stitching in a crowned piece of steel just doesn't cut it...in reality, the cut ends of the original panel need to be stretched and crowned more, slightly, and the fill piece needs to be crowned in two directions. This can only be accomplished on an English wheel, by a highly skilled operator (the original cut-ends are stretched and crowned by hammer-on-dolly work, if they're left on the car...again, labor intensive and needing a very critical and finely calibrated eyeball). The welding process shrinks the metal locally as well (which adds to the flattening of the panel) so this has to be hammered out by hand, post-welding.

This is why a LOT of chops don't come off quite right. There's a lot involved to getting it looking good from every angle.

The nice thing about doing this stuff in plastic is that you can get pretty close, and finish your crown with filler...sometimes what would be scale INCHES thick filler, and totally unacceptable on a 1:1.

[Mike Kucaba]

"The nice thing about doing this stuff in plastic is that you can get pretty close, and finish your crown with filler...sometimes what would be scale INCHES thick filler, and totally unacceptable on a 1:1."

Can you also do that with plastic, laminating thin sheets to build it up? I like slinging putty, but .....

[Cato]

Actually, a chop on ANY roof that has significant crown and requires lengthening of the center of the panel faces the likelihood of a flattening appearance unless the metal man doing the work is really REALLY good.

Bill,

On a 1:1 chop, how are the under surfaces handled? Meaning the weld beads and inner skin of the roof panel(s). Are there methods to keep those from becoming a rusty mess?? And are they done all the time or neglected?

[Ace-Garageguy]

Bill,

On a 1:1 chop, how are the under surfaces handled? Meaning the weld beads and inner skin of the roof panel(s). Are there methods to keep those from becoming a rusty mess?? And are they done all the time or neglected?

Well, like in everything, there is pretty, clean work, and then there's the rest. A really nice chop will remove all of the inner structure first, leaving only the skins to be massaged. Seams on the skins are hammer-welded to make them as clean and flat inside as outside, and to help alleviate the shrinking along the weld area that's inevitable. Then the structure is carefully pieced back together to fit inside the modified skin, to restore the original load carrying ability.

I've also seen chops where the skins were overlapped and brazed, then filled with thick bondo...and the inner structure bodged and hammered into a vague approximation of what it ought to be. Unfortunately, these are the more common.

[Cato]

I've also seen chops where the skins were overlapped and brazed, then filled with thick bondo...and the inner structure bodged and hammered into a vague approximation of what it ought to be. Unfortunately, these are the more common.

So have I which is why I asked. Craftsmanship can be an elusive thing-especially when the customer is uneducated about what he's buying.

[Mike Kucaba]

"Sadly, the stretch method often 'flattens' the roofline of a Beetle......I've heard many 1:1 customizers compare it to chopping an egg. the link below shows a very nice step-by-step done by Chris Clark Customs"

On this chop, can the rear fenders be used? It looks like it to me. The fenders on this bug are molded on. I could scribe and remove them if that makes any difference.

[wisdonm]

If you are going fenderless or with modified rear fenders, then do it my way. The top looks stock, because it is. From the windshield header to the tail lights, it's all one stock piece.

[Modelmartin]

I did this when I was 15 back in 1972. I didn't cut or stretch the roof. I just layed the windshield back and shortened the rear window. It isn't the greatest chop but it worked out OK. I won my age group (13-17) at the MPC contest at the St. Paul ISCA show. I still have the model. The candy Jade Green with Pactra Gold flake over it has alligatored.

[VW Dave]

On this chop, can the rear fenders be used? It looks like it to me. The fenders on this bug are molded on. I could scribe and remove them if that makes any difference.

Clark's method doesn't alter the rear fender area at all, so yes they can....or you can lop them off and go fender-free. Out of curiosity, what Beetle kit are you using?

[Mike Kucaba]

The 1/16th by Revell of Germany. I chopped it already, leaving the rear fenders on. I chopped it like I would a '49 Mercury. I did start at the front and worked my way back. It turned out great! Still have to do the doors, wanted to get a lot of the finishing out of the way before doing that. Even though I braced it a lot. the body was really fragile during the cutting/scribing.

Thanks for the tips everyone.

[Skip]

Bill,

On a 1:1 chop, how are the under surfaces handled? Meaning the weld beads and inner skin of the roof panel(s). Are there methods to keep those from becoming a rusty mess?? And are they done all the time or neglected?[/quote

The inner structure should receive the same degree of close tolerance fitment as the exterior skins. The tighter the joint fit the better the weld, the two panels should butt together. The weld beads are normally ground or dressed smooth, if there was good weld penetration in the first place then grinding the weld bead smooth shouldn't be a problem; as long as you are not grinding the sheet metal,too thin.

Rust control -There are weld through primers, grinders, good old sandpaper, and elbow grease to prep the surface for paint and primer including the ones not so easy to get to. Every surface must be treated sealed and painted or it will rust quickly.

Unfortunately with the popularity of Mig and Tig weld methods hammer welding is becoming sort of a lost art. Hammer welding is normally done with gas welding, the base metal is fused with little or no filler rod, it is the same method blacksmith's used to weld two pieces of metal together. Hammer welding uses more heat which can make a mess quickly if not controlled. Mig and Tig localize the heat, but both can make a mess in inexperienced hands. The. Trick is tack and stitch, not heating the panel up a lot at a time.

Any convex or concave surface is going to flatten a bit when it is stretched. Which is why some builders make as many cuts and seams as needed to maintain as much of the contour as possible. Many shops now have English Wheels to either restore the contour lost in stretching or replace whole or parts of the panel itself.