Is 20 gauge OK for general body patches?

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dibbons

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Debating 18 or 20 gauge. Body guy recommended 20 because it is easier to shape. We are mainly talking about the two front floor patches and two quarter panel patches behind the rear tires. A couple of other small spots. Thank you.

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Debating 18 or 20 gauge. Body guy recommended 20 because it is easier to shape. We are mainly talking about the two front floor patches and two quarter panel patches behind the rear tires. A couple of other small spots. Thank you.

It's an accepted practice from what I have seen and heard, but obviously it's also thinner.
A trade off.
 
That's what I used. From what I could tell on my '75 - even with a micrometer- that was about right for body and pans. Brackets, inner rockers etc were more like 18ga. 'frame' is heavier...
 
It depends if you’re going to but weld
Debating 18 or 20 gauge. Body guy recommended 20 because it is easier to shape. We are mainly talking about the two front floor patches and two quarter panel patches behind the rear tires. A couple of other small spots. Thank you.

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It depends if you’re going to but-Weld or overlap will determine your thickness. Overlapping you can get by with slightly thinner gage on the body...floor pans and such I always go back with equal gage due to their placement.
 
Can't find my notes of measurements I took off the original metal, just remember it was closest to the 20 range so that's what I went with. Also, the floor pans I got from Year One measured in 20 range.
Keep in mind it has a tolerance (chart below). I bought a sheet of 20 from a local sheet metal supplier. Just measured what is left of it .035, so pretty much nominal. Your results may vary.:rolleyes:

steel_sheet_metal_tol.jpg
 
I've heard that the the '73 and newer had thinner gauge sheet metal to off set weight for fuel economy, and that is why those cars seem to rust more.

But I don't know if that's true
 
I've heard that the the '73 and newer had thinner gauge sheet metal to off set weight for fuel economy, and that is why those cars seem to rust more.

But I don't know if that's true
The metal on my 75 duster seems no thinner than my 69 dart, but as for the quality of the steel? I know the steel in my 79 F100 was very soft, especially noticeable in the bolts I would snap, half the body bolts in it were old dodge bolts in it by the time I sold it, figured something happened to steel quality in the 70's
 
Junk 70s steel. Everything rotted to **** fast. Especially rustbelt. Theres a reason jc whitney sold almost entire chevy trucks in new sheetmetal. The metal was ****, and nothing was galvanized.
 
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Are we saying the metallurgy itself was defective back then or the rustproofing/finishing methods were unsatisfactory?
 
Jap crap boxes were even worse. Stamp them tokyo tonkas real thin, and pay their workers with rice to sell em dirt cheap, no galvanizing, then ship em over on a boat. Their vehicle inspection programs in japan meant vehicles got scrapped every 3 years back then and you bought a new one. This was for their gubmint to keep the machines humming and people working. They never expected that people here in the U.S. would actually keep em more than 3 years. But people did, and at the 5-7 year mark the bodys were structurally unsafe in the rustbelt states. I can remember fenders flapping like wings these rolling mechanical assholes going down the highways everything rotted all the way around, and them only bolted at the top. My brothers 79 toyota pickups bed lasted about 5 years then fell apart, and he bought the truck new. Lol

My dad had a 1974 K5 blazer. Metallic bright green, white inset panels with chrome trim. Within the first year he was buffing that white paint where tan rust streaks were staining the white paint from where the body trim holes were. He had that one about a year, figured out what was up and sold it. Bought a 1970 ford club wagon van with a 302. He kept that for years, not a stitch of rust.
 
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Down here paint was crap in the 60's and the 70's even the early 80's, but the 70's cars rusted out faster than the 60's, especially Australian cars, some of that was structurally poor design, some was poor metal, all was poor paint. My first car was a Chrysler assembled Mitsubishi, it had a couple of small rust spots when only a few years old, and that was considered very good for a Japanese car. Hondas and Toyotas started to blister instantly. By comparison my 75 Duster seems painted to a high standard to what we had down here, certainly better than my 69 dart, but the dart had galvanised rocker panels which really helped.
 
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