QuestionQUESTION: I have a '93 Chevy Extended Cab with some rust on the lower cab corners. I am weighing in on replacing with GM full panels cut and spliced across the windows (side & back) with a butt weld finished on both sides. This approach will save the upper third of the existing panel, so as not to have to cut it out across the roof seam. I'd like to know what labor hours are estimated for total panel replacement and if you think splicing is a good way to go vs cutting out the entire panel, considering the way it goes together along the roof seam.
ANSWER: Ax, this would be a costly mistake, it's MUCH cheaper to just go with the lower 1/3 aftermarket panels. It's less work, also. Don't butt weld them, lap the panel at least a half inch. I don't to time estimates online, but what you propose would take a staggering amount of time, and is really the sort of repair only a professional should tackle. here is a tip- pull the carpet out from behind the rear seat, and pull the interior panels out. There is a truck load of highly flammable foam in the cab, and I can't preach caution enough here. Bill
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QUESTION: Why do you recommend lapping the lower replacement panels vs a butt weld?
Wouldn't the edge of the replaement panel have to be formed to create a flat surface on the outside if lapping? Then the lapped area on the backside of the panel could attract and hold moisture, assuming the replacement panel underlaps the existing panel.
Eastwood makes panel spacers for the purpose of putting a slight space between a replacement and an existing panel, then you can tack weld it, moving around to prevent warpage and once tacked in place, finish the weld in sections until completed. Once the metal is "finished" you can't tell it was done. With access to the backside you can metal finish both sides and then protect with a cold zinc coating and good quality primer, plus a rust proofing coating, like Ziebart. That's the plan anyway.
I don't plan to do the cutting and welding work myself. A suggestion was made to me to use stock panels, spliced across the windows vs the lower third replacements. I know the panels cost more, I can get GM panels for just over $200 vs less than $50 for lower thirds, and I know there is more labor involved than if just using lower thirds. I was wondering the approx difference in labor, hour wise, one way vs the other and in the hands of a pro, could be justified in the end result of the overall quality of the job. My truck is not a work beater.
ANSWER: Who are you trying to convince- me or yourself? You won't convince me, I stand by what I say. It's foolish to do all that extra work, and the panels will be no better off than they were before. The rust repair panels will be a heavier gauge metal than stock, and if properly prepped, will last as long as replacing the entire face. You flange the existing panel with a flanger, apply the new panel OVER the existing. Butt welding is no way to install a panel, it goes against every rule of modern panel sectioning as outlined by all the manufactures, and I-car. Even if you section it through the window frames, butt welding is an unsafe procedure. You will compromise the integrity of the panel, and repair, to gain MAYBE a little extra life. In my shop, if you wanted cab corners, put in all the way to the windows, I would happily charge you 1500.00 over my regular fee of 400.00 per cab corner. We are talking the difference of 8 hours per side, painted, or 20 hours per side, painted. That does not include the cost of the part. You are talking about removing the rear glass, the entire rear compartment's interior, and the bed. Trust me, the end does not justify the means. Yes, Have it undercoated with a paraffin based undercoat, it's a clear, amber colored liquid. The black goo is crap, and prevents no rust. Weld thru primers will give you marginally more protection, but make welding a nightmare, I don't care what anyone says. It sucks when every weld gives a lovely little blast of molten metal before it takes, and that is what the contamination of the welding primer does. It will burn away from the weld at least a quarter inch in every direction. That is why proper undercoat is imperative, and weld thru primer redundant. It isn't there in the most likely area where rust starts! Happy sectioning, Axe, and welcome to the fun, fun world of rust repair. Bill
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QUESTION: Okay, I'm convinced, lower panels are the way to go. I can see where it doesn't make sense to spend the extra money, as it won't be noticed in the results or long term durability. I needed help in making up my mind which way to go. I can also see where lapping in this case, over the top and on the ouside, could be easily accomplished. How is the edge finished? Is there a bead run down the length of the splice and then ground down and metal finished? Or is it just tacked and filler used?
If you don't mind I'd like to ask you to elaborate further on why lap welding vs butt welding replacement panels. I see it done all the time on shows like Overhaulin, American Hot Rod, and in how-to mag articles and I see them lap some too.
Thanks for the help. I like to go to a shop with some understanding of what I need, and the best way to ask them to approach the job. Now I just need to find a shop that can and will do it. The big shops all seem to do collision work only and no rust repair. The muscle car resto type shops either don't want to do a truck, or won't give a firm quote. We are not talking rocket science stuff here.
ANSWER: Hey again axe. The panel flanger not only creates a nice little shelf that makes for a flat surface, it leaves a nice little channel between the old and new panel for the weld to go. You see, on a lap without a flange, by the time you dress down the weld, there is just a little bit of weld left to hold the pieces together. If you do this with 2 flat pieces of sheet, then dress the weld down, the weld is easily broken or torn apart when bent. That is why the flanger is best. The metal seam should be completely welded together, with 1/2 inch seam welds. I also will do plug welds every couple of inches, that is just a 5/16 hole drilled into the new panel, abut 1/8 or so below the lip. This adds extra strength. The reason you see guys butt welding on cars on TV shows is just for speed, or for show vehicles that the guys don't want any seams showing in the trunk, or pure ignorance of what heat does to sheet metal. Also, sometimes it's impossible, or impractical, to flange the existing panel to accept a patch. The thinking is, that the lap is a place for rust to start, which is true. I look at it from a stand point of strength, because I'm a collision repair expert. I'll sacrifice a little longevity to gain strength. The vehicle surviving an accident in the area I repaired is incredibly important to me, from a personal and legal stand point. If I butt welded a panel in, and another vehicle blasts through the panel like it isn't there, then I jeopardized that person's safety. That is why I don't like butt welds, the heat permanently weakens the metal, no matter how much skill was involved in the repair. According to I-car, even my flanging technique isn't acceptable on rocker splices, sail panel splices, and splicing a panel through the windows. Much less a butt weld! I-car says to fit the pieces up, and trim them like you are going to do a butt weld, but leave a 1/16 gap between the panels. Then, you take a 2 inch wide piece of sheet metal from the old panel, fit it up and under the existing panel. Then you plug weld it into place, leaving 1 inch sticking down that the new panel laps on to. Then, you drill 5/ 16 plug weld holes into the new panel, every 1-1/2 inches. The new panel is fitted, and the panel is attached at the seam with plug welds. Then, the seam is closed with half inch stitch welds. It's incredibly strong, but prone to catching water. So, it needs undercoated with paraffin based under coat. Sound familiar? But, when I send a young woman and her little children down the drive, I know that if they get hit, my repair will protect them, and the car will react in the way the manufacturer intended. As far as finding a shop, you are correct, nobody wants to do rust. it's filthy, nasty work, and body filler? It always takes tons of it. No fun either! It seldom lasts very long, because customers never follow up with professional undercoating. Restorers want someone who has gobs of cash to throw away on a car, and they want the glory of fixing up an old Chevelle- not a mid nineties Silverado. Keep looking, you will find someone. One of the shops will get slow on work, and be happy to do a nice job on your truck. Thanks for your questions, you have been the most educated person I have talked to and advised so far! I enjoy talking at length on how to do a repair to someone who seems to totally understand the process. Most guys are asking me how to restore cars in an e-mail, it can't be done, and I don't think they have a clue what I'm talking about. I'm sure you will see to your truck being repaired correctly, and beautifully. Bill
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QUESTION: Thank you Bill for your answers. I have learned a ton. Too bad you aren't closer, I'd just wheel over to your shop and let you do it!
I think I am now armed with enough of an understanding to specify exactly how I want it repaired and hopefully to screen shops/bodymen for a qualified candidate.
Thanks again.
PS: What the heck is a sail panel?
AnswerYou are welcome, Axe. The sail panel is the part of a quarter panel between the rear glass frame, and the rear door jamb area. (cars only.) If you look at it long enough, it's shaped like a sail- Hence the term sail panel. A rocker panel is called that because it tends to get hit with a lot of road debris, like stones and rocks thrown from the front tires. The front door hinge pillar is the A pillar, the center pillar that you hang the rear door on is the B pillar, the rear door jamb where the striker for the rear door sets is the C pillar. Like you said, not rocket science, just simple terms. They needed to name the parts something, and the part names usually are simple. But, they make make sense. Once you know which part it is, you usually say "Oh! Well, that makes sense!" Good luck, and have a great day. Bill
