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More Professional Body Prep Tips and Tricks

Posted in How To: Body Chassis on February 23, 2018
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We have followed, step by step and side by side, along with the pros at Quick Draw Jeep Restoration in Huntsville, Utah, to bring you the tips and tricks to elevate your bodywork game. The subject used for this educational process is a super-cool CJ-6A Tuxedo Park, but this information can help with any similar-era Jeep CJ restoration project.

This particular project started with the entire disassembly of the Jeep when it first rolled into the shop, and some frame repairs done with general shop tools (“Tips and Tricks for Jeep Frame Repair,” After sandblasting the body, the sheetmetal that was too far gone was removed, and new panels made right here in the USA (“CJ Sheetmetal Work: Part 2,” were sourced as replacements. We even got the inside scoop on fabricating a rear quarter-panel from scratch (“Jeep CJ Bodywork Tips and Tricks: Part 3,”

This straight and clean old Jeep CJ is almost dry after its last round of wet sanding. It took a ton of man-hours to get this CJ-6A Jeep body into primer. For pro-level bodywork tips and tricks you can use at home, keep on reading to see how it’s done right.

All that’s left now before paint is final metal surface prep. Any good painter will tell you that your paintjob will only be as good as your prep work. We have already laid out a solid base to work with, but it’s still very much “rough around the edges,” as they say. Nothing a little body filler can’t fix though.

That’s right, the dreaded “B” word—Bondo. Almost every restored vehicle on the road has it somewhere. When it comes to Jeeps, after 20, 30, 40, 50+ years on the road it’s almost guaranteed that there are not many flat or fully intact panels left. We went to the guys at Quick Draw Jeep Restoration for some old-school body shop tricks that can help make your Jeep's old body as true as the day it rolled out of the factory door.

One of the oldest and best tricks in the book is the tried and true hammer and dolly for flattening out basic dings in your body panels. Simple dents and dings in the metal can be worked out by using a body hammer, backed up with a body dolly. Body hammers and dollies come in all kinds of different shapes and sizes. Do your best to match the shape of the dolly to the original curve of the panel you are working on.
In Preston’s right hand you can see the dolly he has chosen to work the dents out of this front fender as he hammers from the opposite side.
What’s the deal with all of those dots on the cowl? This is an area that quite a few Jeeps tend to receive damage to in one way or another. While body filler is nearly unavoidable when reviving old Jeeps, Quick Draw Jeep Restoration does its best to make sure the body filler is kept to an absolute minimum. That means some good old-fashioned metal heat shrinking! When sheetmetal gets dented or bent there is thinning and stretching that takes place. Even if you hammer it back into place, the section of steel becomes slightly longer than it used to be, but still needs to fit into the same space. On larger damage areas this creates an “oil canning” popping of the panel in and out as you bounce down the road. That shouldn’t happen. If the problem is not addressed it can cause your new body filler and paint to crack prematurely.
The first step in fixing a stretched panel that is oil canning is to locate the center or top of the domed section that is popping in and out. A welding tip is used on a torch set to get a small, concentrated heat source to the top of the dome.
Once the work area is cherry red and about the size of a nickel, then it is ready for the next step. Only one spot should be worked at a time. Some sections require several heat shrinking sessions to get things right. This is the fourth round of heat shrinking on this panel.
As soon as the torch is shut off, a body hammer is used to continuously tap around the perimeter of the cherry spot. Not too heavy, just right. In a few moments a distinct “POP” can be heard, as the panel will oil can on its own. At that point, a wet sponge in a nearby bucket of water is used to quench the cherry spot back to room temperature. The quenching allows the metal to shrink quickly and forces excess material into a small peak at the center of the hot spot. A quick buzz with a die grinder and sanding pad will flatten it back out smooth.
After each session, the flatness is checked with a straightedge. Pushing on the panel to see if it will still oil can is also a test to see if the job is done or if more heat shrinking sessions are needed. The high number of spots we had to heat and hammer to flatten out all the panels on this Jeep gives you an idea of what it takes to get it right sometimes.
The passenger side of this CJ-6A also needed some metal shrinking work. When this Jeep was torn down for restoration, the sandblaster had a lot of old Bondo to remove. It was more than 3/8-inch thick in some places. The friction of heavy sandblasting in certain spots caused some of the metal warping. Old-school metal working techniques will significantly reduce the body filler needed on the final product.
When choosing body filler, find a local automotive paint supply house to source your materials from. Avoid the lower quality stuff that you see at the auto parts stores. Quick Draw likes to use 3M Premium body filler for its projects because it spreads out smoothly with less air bubbles. Be sure to mix in the correct ratio of hardener paste per the instructions for your materials.
Once the sheetmetal is free of any oil canning action, it is time for the first skim coat of body filler. The skim coat is a thin layer of filler that is spread over the entire body. Most of the filler you apply will be sanded down to the sheetmetal, leaving filler in the low spots of the panels.
The flat sheetmetal is easy, so let’s take a closer look at some of the more challenging, curvy areas. The first step is to spread out a reasonable layer of filler onto your work area. Preston likes to use a drywall hawk to keep his filler supply close to the application zone.
While the body filler is still workable, choose a spatula, trowel, or putty knife that is flexible yet sturdy. Use both hands to form the flexible application tool to meet the contour of the body part you are working on. Take the time to smooth out the skim coat as thin as possible for the coverage needed, sculpting it to the body contours. Choosing a working direction that makes the most sense is also important. Preston is deliberately working the side of the hood from the center down to the fender line and not from the back of the hood toward the nose. This working direction only requires just a little flexing of the tool to meet the CJ hood-line contour.
Excess filler can be carefully trimmed with the trowel blade or a body file rasp after the filler has had some time to stiffen up, but is still somewhat soft. If left to harden completely it will take more time and effort to sand it down later, in addition to making a dusty mess.
A straight-line air sander has a rapid forward and backward motion (in a straight line). The large plank surface is perfect for getting a straight and even surface. There are also basic manual hand-sanding jigs that are available also. As one would expect, the idea is to start with course-grit sandpaper and work your way down to finer and finer grit for a smooth finish.
The straight-line sander did a great job on the center section of the hood, and now Preston has chosen to switch up his game plan and use a Dual Action (DA) palm sander on this next section. The dual action of the sander has a random rotation pattern, so it does not leave swirl marks on your work piece.
Get up close and personal with your work. Your hands are better than your eyes on showing you how even your work is. Any dimple, dome, or poor transition will be felt as you run your hand across the panel. These are areas that will either need some more sanding or another go with the goop.
Getting the body panels perfectly smooth and just right takes several layers of body filler with plenty of sanding in between. This is the third layer of filler on the hood. As mentioned before, your paint job is only as good as your prep work. Any imperfections or unevenness will be visible in your new paint, so take your time and make sure that everything is perfect. No shortcuts or an “it’s good enough” mind-set. A little extra effort goes a long way.
At the end of the day, here is the horse we brought to auction. The filler is as thin and minimal as possible. Notice the factory cutout on the side of the hood was not filled in. All of the body seams were visible from the factory, and we always advocate showing off those panel joints, just as they came out of the Toledo factory.
Where did all the yellow go? The first coat of primer is really what makes the project start to come together by having the Jeep back to all one color, even if it’s still in pieces. Preston’s diligence on the bodywork can easily be seen in the mirror-like reflection of the primer he is spraying. No imperfections can be seen, and that is exactly what the goal is for any paintjob. Speaking of color, we are one step closer to laying down the pigment, but we’ll save final paint prep and spraying for another day.
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Quick Draw Jeep Restoration

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