Hands on Cars Episode 11- How to lay filler and set body panel gaps

Body work is labor intensive, and can take a lot of time. There’s no shame in Tom Sawyering your friends into helping you with the project, and paying them off with beers and gratitude. Kevin Tetz isn’t a regular car guy though, so his friends are some of the best paint, body, fabrication and engine guys in the business. And they all know being owed a favor by Kevin means kick-ass paint somewhere down the road on one of their projects.


The crew for this putty party consists of Chris Slee from Kiwi Classics and Customs, T.C. Penick, Randy Jones, and Jeff Roop from Bay One Customs, John Bouchard a renowned engine builder who’s not bad at body work either, plus Steve Longacre and Jeff Gallagher (someone please check this spelling). Together they use various techniques and professional tricks to do several weeks of body work in the space of a day.


Here it is easy to see why so much work needs to be done. The light colored areas are high spots, and the dark ones are low spots. This is one wavy rear fender.


The Putty Party
While the rest of the team works on other areas, Kevin takes out some good sized dings. First he does some hammer and dolly work, finishing with an Eastwood Bulls Eye Pick on the front fender. Then he uses a stud welder to pull a dent in the sail panel.


1) First he finds a dolly that closely matches the inner contour of the fender, and luckily on this panel it is easy to get to the back side.


2) Placing the dolly against the back of the ding, Kevin knocks it flat again with just a few minutes of hammer on dolly work.


3) Then it’s on to the Bulls Eye Pick, which is like a hammer connected to a small dolly by a long arm, to fine tune the repair.


4) A little bit of grinding and it is as flat as it ever was from the factory.


5) The dent in the sail panel can’t be reached from the back, so for that one Kevin uses a stud welder and slide hammer puller. First you spot weld a series of studs to the low portions of the panel with a dedicated stud welder, or the Eastwood adapter for a MIG machine.


6) Grab the stud with the chuck on the end of the slide hammer, and give it a couple of shots to pull it flat again.


7) Then just snip off the studs and grind the welds flat again.


Chris Slee from Kiwi Classics uses some leverage and a handy piece of 2 x 4 lumber to twist the hood just a bit, to fix the alignment.


A push here and there and it is better than the factory ever got it.


The problem is, the fender and the hood are 2 different stampings, and the crown is rarely ever the same front to back on all 3 pieces from the factory.


Once that is done, Chris adds some metal to the rear edge by the windshield, to get a much better continuity of the panels than the factory ever gave the car.


Instead of wasting time trying to fix the rusty, sprung, dented old deck lid Kevin just replaces it with one from Molt’s Used Auto Parts in upstate New York.


T.C. Penick from Bay One Customs has shown us how to fine tune panel gaps for the Zed Sled, all the way around the hood and trunk lids.
1) You start by filling in the gap with foam tape.


2) Next fill right over the tape with Eastwood’s fiberglass short strand body filler.


3) While the filler is still soft, take a homemade panel gap tool, that’s a wooden paint stirrer stick, with a razor blade attached to either side, and cut the gap out. Don’t remove the filler yet though.


4) Let the filler harden than just block right over the gaps until it is smooth.


5) Once you are done with the blocking you can peel out the strip you cut earlier.


6) Then with a paint stirrer wrapped in 80 grit paper, sand for a perfect 5mm gap.


Next Chris Slee moves onto shrinking some domed out spots with a acetylene torch, and some hammer and dolly work.
1) The center of the domed spot is heated red hot.


2) Hammer around the red hot area, pushing the metal toward the center with each blow. Don’t do any hammer on dolly directly on the red spot, or you will stretch it further.


3) Quench the hot spot with water, then you can fine tune it with more hammer on dolly work, even directly in the center.


The composite spoiler needs some work too, so T.C. cuts some cloth and lays it on.


Then spreads the resin over it, just as if it were a coat of paint applied with a brush.


Working with a bunch of pros, even Kevin learns new tricks, like using a small wire brush to clean out the grit of your sand paper when shaping body filler.


Spraying Primer/Surfacer
Now that the body work is all done, it’s time to spray out the Contour Polyester Primer/Surfacer. This product is like a lower viscosity version of the regular body filler that can be sprayed out of a gun. They build like crazy allowing you to block wavy panels flat and crisp up style lines, and they don’t shrink, giving you a great foundation for the final sanding 2k primers.
1) Start by thoroughly agitating and mixing the primer, if you have a shaker that’s even better. The snap on pourer lids make measuring and mixing a breeze.


2) Then mix the catalyst into the primer/surfacer with a ratio of 1/2 of a small bottle to 1 quart of primer.


3) Spray it out of a huge orifice gun, in the neighborhood of a 2.5mm tip, and work slowly, close to the surface with a 75% overlap. This stuff is meant to go on thick, and will seldom run. Most of it will end up being sanded off anyway after all.


4) Zone prime the car panel by panel, not worrying about keeping the wet edges down or overspray. This stuff is meant to go on thick, it is body filler after all.


5) 3 coats, or a gallon is enough to do most of your initial blocking. For a show quality car, which this will be you may have to do another round of blocking with the poly primer/surfacer before moving onto the 2k primer and paint.


6) Next apply a guide coat, then wait for everything to dry and you can start blocking. A guide coat is simply a contrasting color paint that lets you see high and low spots as you sand.


Kevin has talks about some of the important points sanding and sanding blocks:
1) Shaping is done with grits of 200 and lower, and sanding is grits of 200 and above.
2) You need different shape and stiffness of sanding blocks to handle different contours and body shapes.
3) You never want to sand across a style line, you want to sand up to it and down to it from either side.
For the initial shaping of the primer/surfacer Kevin starts with 120 grit paper and a selection of Durablocks and Soft Sanders.


Sanding in an X pattern, you can quickly see the low spots where the guide coat is left after sanding.


Here Kevin shows you how to work up to the style lines and not round them off. In fact you can even sharpen them up this way.



You can also use a piece of masking tape along the edge of the style line to help sharpen it up. Sand into the tape, then tape the other side of the line and sand into it from the other direction. After blocking both sides you can see how imperfect the factory stamping was, but don’t worry that can be fixed with more blocking before the paint goes on.


Another good way to see the overall progress of your blocking is to wet check it with the reflection of light in some PRE painting prep sprayed on the body panel. The more accurate the reflection is, the closer you are to being mirror smooth.


Blocking takes time and labor, but when you see the mirror smooth gloss of the paint afterwards it is totally worth it. Kevin wants to send a special shout out to the online community at NastyZ28.com for their help and encouragement with this Zed Sled project. Next episode more primer and hopefully some actual paint.

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