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Sheet metal thickness


jbojo
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What is the thickness (Ga) of the metal used on body panels? Thx!!

-john

(jbojo)

351C 4V cc heads, 10.5 : 1 CR, 290 Herbert cam, Flat top forged pistons, forged connecting rods, Atomic efi,

C6 with Gear Vendor overdrive, 3.89 Tru Trac, Hooker Super Comp with 2 1/2" Pypes Exhaust.        

 

Some Mod pictures can be seen at: [button=http://www.7173mustangs.com/forum-garage?filterxt_uid=2026]Bojo's Garage[/button]

 

 

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I believe original panels were 18 ga. but that can be a PITA to work with if you are patching a spot.

73 Grande H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

 

- Jason

 

 

082-hot-rod-power-tour-2017-1970-1970s.jpg

 

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You might find that the material is several different thickness. When you quote panels for cars/trucks you quote to the nominal gauge thickness then you order the steel from the mill to the min. thickness. Those few thousandths of an inch are where you usually make your money. Here is a link to a standard gauge chart with tolerance. http://www.simonsconsulting.com/steelthickness.htm

When they roll steel the mill rolls deflect some so the center of the coil is thicker then the edges. Some parts have such a tight tolerance today that you have to keep the coils sorted by where they came from and make tooling adjustments to run right, left or center slit coils.

Too much info I know.

I don't have a car here to measure anything. While making parts for Ford, back before they changed the pickup body styles in the 90's, the sheet metal thickness in a F-150 was thinner than material used in the F-250. Only a few thousandths of an inch but thicker. They used the same dies for both models so the panels coming out for the F-150 sometimes did not look as good.

If you buy some material to repair body panels ask for CRS Cold Rolled Steel and if you are going to bend and shape ask for a low carbon content also, CRS-1006 would be great. The 10 tells you it is plain carbon steel not an alloy and the 06 is the % of carbon. A higher carbon content cracks easier but is tougher. An example of an alloy steel would be 4140 or chrome molly and very tough.

The next time you are in a parking lot look at how many door dents are in the Japanese cars compared to a Ford. The Japanese companies use the cheapest easiest forming steels they can buy. At one time the press lines at Honda, Ohio and Japan only had four press in each line. The typical U.S. plant has 6 presses or even 8 for some of the Ford lines. So the Japanese limited themselves to what they could form. Ford was using a lot of bake harden materials in skin panels which reduces door dents but makes them very difficult or impossible to work with after a crash. So the Japanese cars can be made much cheaper due to Mfg. costs and material costs. They just don't give the customer the money they keep it.

Now I know that was way too much info and still did not answer your question. I should be in politics.

When a man is in the woods and talks and no women are there is he still wrong??:P

David

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Thx guys, I need to make a few patches and I ordered some .023 wire so that I can keep the heat low when I weld.

-john

(jbojo)

351C 4V cc heads, 10.5 : 1 CR, 290 Herbert cam, Flat top forged pistons, forged connecting rods, Atomic efi,

C6 with Gear Vendor overdrive, 3.89 Tru Trac, Hooker Super Comp with 2 1/2" Pypes Exhaust.        

 

Some Mod pictures can be seen at: [button=http://www.7173mustangs.com/forum-garage?filterxt_uid=2026]Bojo's Garage[/button]

 

 

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Did you get the Easy Grind from ESAB? I had to wait a month or so to get my roll. I haven't used it yet, but it's supposed to be softer than 70-s6 and easier to blend with panels.

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Did you get the Easy Grind from ESAB? I had to wait a month or so to get my roll. I haven't used it yet, but it's supposed to be softer than 70-s6 and easier to blend with panels.

 

Yeah I have that but haven't used it yet either. Waiting for my metal brake to arrive so that I can fab my parts. I was lucky as this wire is available locally.

-john

(jbojo)

351C 4V cc heads, 10.5 : 1 CR, 290 Herbert cam, Flat top forged pistons, forged connecting rods, Atomic efi,

C6 with Gear Vendor overdrive, 3.89 Tru Trac, Hooker Super Comp with 2 1/2" Pypes Exhaust.        

 

Some Mod pictures can be seen at: [button=http://www.7173mustangs.com/forum-garage?filterxt_uid=2026]Bojo's Garage[/button]

 

 

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I use the .030 wire for everything. And I use a good amount of heat and speed. I move fast and don't concentrate the heat in one area to minimize warping of the panel.

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Interesting write-up by David. I would add that the stamping process also stretches the sheet metal, in places, reducing the thickness, so that a single panel can appear to be more than one gauge.

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

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I use the .030 wire for everything. And I use a good amount of heat and speed. I move fast and don't concentrate the heat in one area to minimize warping of the panel.

 

.030 takes good bit of heat to weld a panel. A lot more likely hood of burning through thinner metal and warping with .030. With .023 I find it lays down a lot nicer with less heat. Gotta watch grinding weld down too... you can put a lot of heat in the panel just from grinding. And 030 seems to leave more weld to grind off. but whatever works for ya. I keep a wet shop rag with me and keep cooling the panel after every couple tacks. Heres firebird quarter I finished this weekend.

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Kevin
1971 Mach 1

408C Stroker - C4 w/3,000 stall - 8.8" Rear w/3.73's - Disc brakes all way around.

 

 

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Interesting write-up by David. I would add that the stamping process also stretches the sheet metal, in places, reducing the thickness, so that a single panel can appear to be more than one gauge.

 

They usually only allow max of 10% thinning. I was reading an article the other day where Ford actually went from the bake hard on the Mustang door skins to DP 500 Dual Phase 500 which is crazy tough. If that door skin gets bent you will never body work it. I was surprised they made it but they did have to work the dies and it will for sure wear the dies much faster but you will never see a door ding in one of those. So there is a big change in the middle of a Mustang run that future forum members will be wondering why some of the doors are so tough, lol. You could body work the doors before the change but not after.

Do you guys hammer and dolly your welds as you go along? Helps with the buckles also. As with any weld the molten metal shrinks when cooled so it tends to pull the surrounding metal.

When a man is in the woods and talks and no women are there is he still wrong??:P

David

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Nice! I did quarters, inner and outer rockers, and floors, built a 2x3 square stock rear frame, and did a a mini tub to my 74 formula.

 

Ya your probably right about to much heat and material. Not a body guy but I do a decent job. My old man was an awesome body guy. He stared off with lead. He would shrink and stretch the metal to straighten it. I just could never pick it up like he did.

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