How do i chop my truck?

ok guys, i got a 1959 chevy stepside that im considering chopping the top on. iv never done it before but im not that bad of a welder and i'm not in a hurry to get it done. How do you guys suggest i go of doing this project? What kind of bracing am i going to need to reinforce the cab? where should i make the cuts? where should i add the additional roof metal? how to i keep the rear curve of the cab intact? what do i do with the curved windshield? how to i chop the doors? what other things do i need to know?

 

look up tex smiths book on choping a top and read everything... 3 times!!! you'll get some ideas and know how on what to do and if you can tackle it.

 

I've got a small window and have contemplated the chop.
I'd cut the back the 4 3/8" that is below the rear window to get rid of that entire panel without cutting the back glass at all. That's what I did when I chopped my '40 GMC.
I'd cut the A pillars that much or maybe a little less, whatever it needs to fit the glass.
You need to cut the glass, then fit the metal to it, because glass doesn't like to bend.
Cut glass, cut metal, fit, maybe trim more glass, fit more metal, etc.
The double inner roof probably needs to be cut out for access to the outer B pillar to pie cut it to shape and welded back in carefully, so it doesn't warp.
Id just angle the posts (and door glass channels inside the doors) ather than widen or cut the top above the drip rails at all.

 

I'd find someone that know's how to chop a truck and feed them beer and pizza till it's done. Don't try it by your self!!!

 

first I'd find someone that can cut that curved windsheild, if you can do that then think about how to cut the metal

 

Re: How do i chop my truck?


A sawsall

 

Hey,
The toughest part of this chop, on this era GM truck will be that
curved windshield. Find a real auto glass guy, not someone who
"thinks'' he can cut curved glass, and bring him into the project
early. At four inches these will drop down nicely without butcher-
ing the center roof panel. NEVER quarter a roof panel to chop a
vehicle! That only makes for hours of unnecessary cutting and
welding, to say nothing of filling and sanding. Look to make any
of your cuts in the flatest most vertical areas of the posts if at
all possible.

 

about the glass? i've read that you can cut glass with a sand blaster and masking off a portion to be cut. does that work? if it does im considering trying it becuase the glass in the truck has got some chips and cracks and bubbles in it already. otherwise, who could cut the windshield? glass repair man? lol, i dont know. what kind of process to they go through doing it?

 

With all due respect, if you're asking, you're in over your head. Chopping tops, sectioning....this is the custom equivalent of brain surgery. Find someone who knows how to chop a top, and has done them before, and have them walk you through it.

50's iron are among some of the hardest cars to chop, your truck is not a real good beginner project

 

Hey,

As chops go, this era GM ain't a bad beginner project, cutting the
windshield excepted.

Little major metalshaping, small welding to be done, and tall enough
so you don't have to stoop to work on them.

All of this is based on a mild to medium chop. Go much above a 4''
chop and the whole game changes.

Early model highly crowned roof vehicles require much more plan-
ning and a much higher skill level to chop well.

Swankey Devils C.C.

 

Here's some info on cutting that glass with a sandblaster...

It all comes down to safety laminate or tempered. If it’s tempered it will go BOOM no matter what you do. If it’s lammie it just takes time. Cutting flat glass you can use the glass cutter and lighter fluid method, but that's lousy for cutting curved glass. I’ve done a combination of both, blasting to the laminate from both sides then a combo of cutting and burning. I’ve also done just blasting and cutting. The problem is that the laminate is a resist, and a tough one at that, so blasting through it is a pain in the ass.

So here we go... blasting through any piece of glass is just a matter of method, and PATIENCE.

Masking: ("resist" is like masking tape for sandblasting)

Duct tape is a useless resist as it’s mostly fibre. You want rubber or vinyl or plastic. Ideally you mask off almost all your window (on both sides) with something simple like clear shelf liner (MacTac), leaving about a 1/2 inch back from where you want to cut. This just protects the glass from overspray and scratches but doesn’t need to be heavy duty. Nor does it need to be clear but I find it easier to pay attention to what I’m doing. Do watch out for heavy duty adhesive as it’s a bitch to take off big sheets of mask when it’s fighting back.

Overlap the MacTac with electrical tape or (funnily enough) sandblast tape (available from a lot of sign making, auto customizing shops or online). Venture Tape is a good one and comes in various widths, from pinstripe to 6”. Cover past where you do want to cut and then cut away the part you don’t want, creating the edge of your windshield. If you use electrical tape or some thin equivalent you’ll likely want to use at least 2 or 3 layers as you’ll be cutting, not just frosting or carving, and your grit will eat your resist. Make sure you tape all around your other edges too so as to not have them lift from overspray.

Blasting media:

When you go to blast use a fairly fine a grit if possible, ie 100 or 120, and preferably aluminum oxide - NOT sand. A lot of commercial “strip ‘em” blasters use much courser grit (60 or 80) and it’s like throwing rocks. Then again super fine like 200 and up is too fine for cutting, and glass beads etc are useless.

Air Pressure:

You want to blast about 80 psi if possible. Most siphon systems only go up to 60psi at the nozzle, no matter what the compressor may be throwing, so will take much longer. Pressure pot systems are the way the to go if possible.

Nozzle:

Use a fairly fine nozzle; 1/8” ideally so you’re actually creating a cutting tool not just a spray. Ceramic nozzles burn out fast; have a few on hand (they’re usually about $5 - $10 bucks). I can go through a ceramic nozzle in about 3 hours at 100 psi. (That’s why I use $300 boron nozzles; and still only get about a year out of them).

Cutting:

Heat build up is your enemy so you want to keep your nozzle moving. Just keep doing back and forth passes of 3 or 4 inches at a time, keeping the nozzle about an inch from the surface and angled slightly away from the tape so it doesn’t undercut and lift it.

Be patient:

For a windshield you’re looking at an hour a side, erring on the cautious side. By going back and forth along the length of your cut like you want to etch a trough before you try to cut through. That way if you start a “run” (a moving crack) it’ll follow the already cut area (in theory) rather than zooming off into parts unwanted. So just work your way back and forth from one end to the other until you encounter your laminate (you’ll know; you’ll suddenly be seeing blackening plastic). You want to cut through the glass using a “connect the dots” technique, ie. as you encounter your lammie move along and continue somewhere else until you get the same thing happening. This is again to prevent runs.

With normal glass this is pretty tricky on long pieces as the pressure can cause the top part of the glass to flip off taking chunks with it. With a laminated windshield the lammie holds it all together, but be careful of the waste-side of the glass flopping around and creating weight and pressure.

You’ll find it best to have your glass clamped on some kind of rack or support frame, preferably with a support bar just below your cut line to relieve torque. Work your way back and forth until you’re through the whole thing, doing the “connect-the-dots” until the whole thing has been pierced on the one side.

Take it out, flip it over, reclamp, and repeat. This time you will want to clamp the top part too so it doesn't torque back and forth and crack the uncut parts.

Cutting the laminate:

Now that you've blasted through to the laminate on both sides you can carefully cut the laminate with an Xacto. Again, be patient and take your time. Many light cuts is better than one heavy cut.

It’s easier than it sounds; just not something that translates into words well. Hopefully this makes some sense. A lot will depend on whether you’re renting a booth or a cabinet as it’s a hell of a lot easier to do big glass in a big environment.

 

that should be a tech post, good info

 

I've done at least 15---- 55 to 59 Chevy truck small and big windows they are not that hard, if you stay with a 3
or 4 inch chop, I'm doing another one right now with a 3 1/2 chop, i cut all my own glass, I did the purple 59 fleetside,and then painted it candy green with green flake scallop's , does any one have any pictures of that truck i don't, how crazy is that if i get time i can walk you throw the trucks chop pm me ------0z

 

thanks alot Big A, great info. ya, im thinking 3 to 4 inches on the chop so that i dont have to cut the rear small window.