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33 Chevy 5 Window Top Chop

9K views 25 replies 9 participants last post by  antiquecar 
#1 ·
CAN ANYONE RECOMEND HOW TO MAKE CUTS TO RE-ALIGHN THE REAR SIDE AND WINDOW AREA? I TOOK OUT 3 INCHES. THIS IS MY FIRST CHOP AND I HAVE READ ALL I CAN FIND, BUT OF COURSE THERE IS NOTHING SPECIFIC TO A CHEVY. I UNDERSTAND HOW TO ALIGHN THE SIDE AND FRONT POSTS BUT REALIZE I BETTER NOT WELD ANYTHING UNTIL I FIGURE OUT THE BACK. NEITHER THE SIDE WINDOW OR THE REAR WINDOW LINE UP. I'D SAY THEY ARE OFF BY 3/8 INCH. ALSO, IF ANYONE KNOWS OF ANY INFO ON REPLACING THE WOOD SUB FRAME WITH SQUARE METAL TUBING I'D REALLY APPRECIATE IT. THANKS GUYS.
 
#2 ·
Welcome to the board

Good to have another member now:

1) Turn off the caps lock..all caps is considered shouting and is bad manners..!!

2) Please post your question in the appropriate forum..In this case the Body exterior forum ad ther are people who have been through this over there that will be glad to help you..

3) we do have an extensive knowledge base as well as some recommended reading material that may help you..

4) Be a bit patient and not to worry..chops can be a bit difficult but it has been done and this one can get done as well..
:thumbup:

Take care

OMT
 
#7 ·
HOLY ---- ! A LIGHT BULB JUST WENT ON ABOVE MY HEAD! ALTHOUGH THE SIDES LOOKED PERFECTLY STRAIGHT UP AND DOWN AND THE FRONT POSTS ARE PERFECTLY STRAIGHT, I THINK THE BACK SECTION MUST HAVE HAD A VERY SLIGHT SLANT TO IT. I THINK I HAVE TO CUT THE BACK ROOF FRONT TO BACK AND SPREAD IT 1/2 INCH AND EVERYTHING WILL LINE UP!
DOES THIS SOUND LIKE THE RIGHT SOLUTION? NEED TO HEAR FROM SOMEONE WHO CHOPS TOPS TO TELL ME I'M RIGHT PLEEEESE!

Still need to hear from anyone who has replaced body wood with steel.
 
#8 ·
This is awfully hard over the computer monitor with no pictures., But NO you do not have to widen that roof. With only a three inch chop there is no way you would have to widen it.

Is there any way you can post some pictures? Does the width of the top line up? In other words at the door jamb, does it line up there? The rear window area is easy, it is just sheet metal, you can cut and do anything you want. The width of the top at the door jambs, that is where you need to start.
 
#9 ·
The pictures are in my gallery. the width of the roof at the side posts is fine and the width of the front posts is fine. i think the width at the rear sides must have slanted slightly and is now not as wide as the body area it needs to align with. take a look and see what you think.
Thanks so much for the input.
 
#10 ·
Hi
I thought my eyesight was bad!! (grin) Check out the book "How to Chop Tops" by Tim Remus, published by Motorbooks International. Lot Of picture, examples and explanations. Whatever you do, do not cut top into four pieces.
Good luck, Bob :cool:
 
#11 ·
if your side posts and front posts are aligned I would suggest putting a couple of tack welds there to hold it in alignment then focus on making the mods to the rear section to get them aligned. Numerous pie cuts and pieces of filler material may be needed to get the right shape. I would concentrate on the rear window area first then work your way to the side window areas. Even a 32 ford will require some adjustment in this area for a perfect fit, but not 3/4 of an inch. Some pics sure would shed some light on this and offer more suggestions for you. Take the time to look the situation over really well before you make your cuts. Refering to the before mentioned book will definately show how the adjustments need to be made. Take your time to make the pieces fit well and it'll work out just fine. Bob
 
#12 ·
FREEFALL said:
The pictures are in my gallery. the width of the roof at the side posts is fine and the width of the front posts is fine. i think the width at the rear sides must have slanted slightly and is now not as wide as the body area it needs to align with. take a look and see what you think.
Thanks so much for the input.
The one thing that I am more concerned about than the poor fit at the window edge is the poor cutting and the backing you are you using.

If you brought that car in my shop, do you want to know what I would do? I would pull the top back off. Using a die grinder with a cut off wheel I would carefully cut the welds being careful not to cut through the skin and remove that backing metal. Then I would correct those cuts (probably lowering the top another half inch would be needed) so they fit better. I would butt weld that seam and THEN I would start fitting the window edges.

Honestly, you have made a lot of work for yourself. That backing is a KILLER. you can use the backing on the center and front posts, but along that long cut around the back, you need to be able to move the metal, cut push, hammer and dolly until it fits. All while welding here and there to keep it aligned.

The widow edges are a piece of cake. You simply cut a section out and move it forward or rearward to make the edge mate up. If you move it to where there is a gap at the other end, you add metal to it. If you move it back where there would be an overlap you trim off the eccess and weld it in place.

I will try to make some drawings tomorrow and post them. But honestly, think about removing the top and cleaning up those seams.
 
#13 ·
Thanks for input. I actually got the idea of the backing material out of the book "how to chop tops". they said it would improve the strength by double. It sounded like a good idea on a car with body wood.
the top is free to be lifted off anytime. i am also new to welding. i take it that my seams must be perfect before welding. Not knowing any better, i thought they could just be filled with weld. But i would'nt be on this site if i thought i knew everything, so i am listening close to everything you say. The backing plates can be ground off with a cutting wheel if necessary with out too much trouble. awaiting your drawings. Thanks again.
 
#14 · (Edited)
Yeah, you need to get the seams much better if you want a nice job. You "could" use a backing like that to make up for a poor fit, but on a top chop on your cool old Chevy, I wouldn't. Backing like that works well on something like a rocker or windshield post where you can't get behind the weld with a dolly. But on something like that, especially where you need to do some "massaging" to get the metal to fit better, the backing is totally wrong.

I am not sure, the windows are such an odd shape you may have not had a choice. But many times, the top can be strategically cut to eleminate or greatly reduce the mismatch at the windows like that.

If you want to pull the roof off and start again, you need to look for the lowest area of the cut and then make it all match that. A metal ruler can be bent around the back of that top so you can get a nice straight line. MEASURE, MEASURE, MEASURE all points to be sure you are going to make it all even.

The following diagram is pretty self explanatory but just toss any questions my way (or for anyone else that may want to respond of course). Sorry about the poor scan.
 
#16 ·
I need some ideas on replacing all the wood too. The best I can come up with is using thin walled square tube and either cut or bend it to match the shape of the panel I'm reinforcing. But then how do I attach it? Drill holes all the way through both sides and plug weld it on? should we just start with flat stock, form it to fit, then weld on bent tube to that for strength. On my prject I need to replace wood everywhere. The body is mounted to the frame by wood, all I have are door skins, there are wood supports throughout the roof, the windshield frame is all supported by wood, wood everywhere. Its going to be a large undertaking.
thanks

Gary
 
#17 ·
We replaced all the wood in my brothers 22 Buick Roadster. What we did was to use square tubing mostly. We made a template of off the body where it would be located. We then cut one side of the tube to that template. On the roadster the body is so short vertically we just left the tubing straight on the inside. We boxed in the tube where it was cut and then welded it to other pieces of the tubing structure with only a tack here and there to the body it's self. On many parts like the bottom of the doors for instance, we left the tube straight, being it was hidden behind the body skin anyway. If it didn't match perfectly with the actual skin, you would never know. The strength would still be there. After all the structure was welded together it formed a sort of "roll cage". We used the actual nail holes in the body panels where it was nailed to the wood to plug weld the skin to the structure. In the roadster body EVERY single part of the stucture was fabed by my brother and I. There is literally no structure what so ever in those old GM open car bodies. No floor, not even a thicker metal around the bottom. The skin of the body simply had a 1/2" fold at the bottom that was nailed to the wood floor! The door skins were only SKINS with a 1/2" lip around the edge to nail it to the wood.

If you take one piece at a time, don't look at it as a huge project, just one piece at a time, you will get it done.

I worked on a 35 Chevy sedan once where the guy had replaced all the wood with perfect copies of each wood piece. He made these hollow pieces out of 1/16" or maye 3/32" flat stock all tigged together. They had lightening holes with chamfered edges. It was a friggin work of art. But after all the interior trim is installed all that art work is hidden. My brothers car isn't that beautiful under the upholstery but it looks darn good. I really think the trick is to not try to copy the wood, just do what makes sense to replace the structure.

I will dig up some photos to post. Here is the finished product.
 
#18 ·
On replacing wood...

My advice on replacing wood is to not get too carried away. MARTINSR makes a good point by noting that it ALL (except the sills) gets covered up. If wood will do the job structurally I see no need to replace it. On my '36 (the last year they used wood) I replaced all the wood in the doors, and the wood around the trunk opening. Everywhere else I (1) used the original wood (2) fab'd a new design out of wood, or (3) purchased new wood. There are no nails in my car... replaced them with brass inserts/machine screws or sheet metal or wood screws.
The wood over the doors and around the rear window was like new. Fab'd a new design around the port windows using plywood. Purchased new b-pillar wood. Built my own sills out of some real nice hardwood purchased locally.
I believe the only really critical wood replacement is the doors. Every single rod I have personally seen, that retained the door wood has problems, hard to open/close, sags, etc. I did not use any tube steel in my doors but used a 'stress panel' design. The inner door is made up of 3 panels, the 2 top ones are removeable, the lower one was welded in place.
I also believe there may be some sound deadening properties with wood, particularly the sills and b-pillars. You can view some of what I did here...

http://pg.photos.yahoo.com/ph/bikeopellidave/album?.dir=ae25&.src=ph&
 
#19 ·
thanks guys, as far as keeping any wood, I just don't think it would hold up to extended 80 mph driving over a few years. I want to replace it all. I like the idea of the flat stock welded together with lightening holes, it probably would look like the skeleton of an old airplane, might be a good enough interior until I get around to filling it in. I really like the all mechanical look with everything made of some sort of metal. Guess I'll just go out and tear into it. Thanks agian, any detailed pictures would be appreciated.

Gary
 
#20 ·
Making body bracing

One can use square tube for this..a gentle curve can be made by using a hyd press and making a curving die..this will put in a gnetle sweep by pressing and moving the tube back and forth..

Bigger sweep (more curve) saw kerf the tube with a hack saw and bend it to suit and weld the kerfs shut..

Tight curves can be made by taking out a pie shaped segment and bending the shape and then welding the cuts shut..

0.60 wall tube in the sizes needed is readily available..

one just needs to either skip weld the body panels on or plug weld through the existing holes left by the old fasteners..

Takes some fiddling to get the right shape..

another thing to do is use a bit larger tube and cut the sweep into the tube..this makes a three sided piece and gives a good result as well..if you have a power hack that can be used in the vertical position this makes this job a lot easier..

Haaving a moaning chair to set and think a bit before cutting helps as well..:pain:

OMT
 
#21 ·
gahi,
gahi said:
as far as keeping any wood, I just don't think it would hold up to extended 80 mph driving over a few years... would look like the skeleton of an old airplane..."
I don't want to sound like an advocate for the wood industry, and I fully support any rodder's decision to build his project anyway he wants to, but since you bring up the subjects of airplanes, read the following taken from a homebuilt aircraft publication I have...
."Wood is the oldest aircraft structural material, but has a poor public acceptance. The strength-to-weight ratio and fatigue resistance of wood is excellent, the problem is simply its susceptibility to rot. Properly protected and stored, a wooden airframe will last decades. But if not cared for, it will be destroyed in a few short years.".

A good example, in my case was the sills. More than half of the surface was exposed to the open road for a half century, there was no sign of any preservative left, and they were still 100% structurally sound.
The ONLY reason I advocate keeping some of the wood is because it saves a tremendous amount of time and effort.
 
#22 ·
LOL, I have been IN planes with wood structure flying faster than 80 MPH and the planes were sixty to eighty years old! :)

No, the wood works, if it is there. If you have to make it, it depends on what you are good at,wood or metal. I myself will use metal.
 
#23 ·
MARTINSR said:
...it depends on what you are good at,wood or metal...
Well, not quite... There are a few guys around the country that make a lota wood parts. i.e., I got my b-pillar wood from one. The b-pillar wood on a '36 is full of all kinds of weird shapes and angles. This part would have a 'high degree of difficulty' rating if it were to be re-produced outa wood or metal. It was relatively cheap just to purchase and installed these high quality hardwood store-bought wooden ones, and a whole lot faster.
 
#24 ·
you guys make a good point about the wood in old aircraft. I was out in the garage contemplating and I looked rellay close at all of the wood. It seems like alot of it was there just to hold the interior. the car is a 28 Hupmobile, there is about 1-1/2 in thick wood on top of the frame that the wood that supports the body is mounted to. much of it is missing and the rest is pretty rotten. My plan now is to take 1x2 or 2x2 tubing and make templates of the wood to trace onto the steel. then cut the tube leaving the flat surface to box it back in, kind of like taking a pie shape out of the ends. for the roof I'll bend the tube to the right radius. I may leave most of the wood that only supports the interior, if its in good shape. Otherwise its getting the axe.
thanks

Gary
 
#26 ·
Fellows don't let wood scare you. It will hold up to what you are planning. Over the years i have reconstructed many wooden frames and I am currently working on a 1923 Moon that has a complete wooden frame. I use styrofoam panels (glueing together insulations sheets) and an old electric carving knife to make mockups. It is cheap and easy to work with and if you screw up you can just glue it back together. Once you have a pattern you can make the part or have some one else make it up for you. The pattern is the important part. Regarding tack strips I use modern plastic material designed for modern convertible tops. I have used this material on my last three cars and they work great. You can use a staple gun instead of tacks with this material. :welcome:
 
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