Just joined? Please introduce yourself.
Classic Edge Designs, LLC Prime Custom Cars, LLC MadMooks
Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 36

Thread: Pitfalls of flanged weld seams

  1. #21
    Registered Member BamaNomad's Avatar
    Join Date
    Nov 2016

    Member #:3217
    Location
    Rocket City, USA (Huntsville, AL area)
    Posts
    998
    Quote Originally Posted by chevynut View Post
    Yes I agree that if you take a patch piece from a car from the 50's it's going to be different composition than metal taken from a car built today. Today's cars are made with thinner, stronger steel. I wouldn't think of using metal from a modern car for a simple patch panel.

    However, that doesn't mean you can't get metal of the same composition that they used in the 50's, which was probably a mild (low carbon) steel. Plain mild steel sheet you can get today is usually something like 1008 to 1020 steel (.08% to .20% carbon) and it's likely similar to what they used back then. I'm not sure but I doubt the thermal expansion of mild steels differs much.

    CN? Do you have some information to back up this statement?? " Today's cars are made with thinner, stronger steel. "

    I don't think there's any doubt of today's sheet metal (used in cars) being THINNER, but 'stronger'?? That differs from my understanding. I think today's car bodies likely use 'bends and contours' to make the panel strong enough, in spite of it being thinner (and likely less strong)...' If today's steel used in auto bodies is stronger, I'd really like to see some detailed information so I can modify my opinion...

  2. #22
    Registered Member
    Join Date
    Apr 2012

    Member #:571
    Posts
    3,496
    I think that all the "stronger" steel is not the steel panels you see - but the structure they are spot welded to. Which doesn't really compare to any kind of 50s/60s maybe even 70s cars.

    Also think about that structure. It needs stiffness as well as strength. Stiffness doesn't come from special alloys. It comes from shape and thickness.

    One thing that IS different about the modern bodies is that the steel has galvanized coating that's far more corrosion resistant than mild steel.

  3. #23
    Registered Member chevynut's Avatar
    Join Date
    Nov 2011

    Member #:115
    Location
    Fort Collins, CO
    Posts
    9,343
    Quote Originally Posted by BamaNomad View Post
    CN? Do you have some information to back up this statement?? " Today's cars are made with thinner, stronger steel. "

    I don't think there's any doubt of today's sheet metal (used in cars) being THINNER, but 'stronger'?? That differs from my understanding. I think today's car bodies likely use 'bends and contours' to make the panel strong enough, in spite of it being thinner (and likely less strong)...' If today's steel used in auto bodies is stronger, I'd really like to see some detailed information so I can modify my opinion...
    http://www.worldautosteel.org/steel-basics/automotive-steel-definitions/

    http://www.worldautosteel.org/steely...your-strength/
    Last edited by chevynut; 03-06-2018 at 07:47 PM.
    56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension

    You can see my 56 Nomad build here http://www.picturetrail.com/chevynut

    For affordable C4 Corvette Suspension conversions for your car, visit http://www.classicedgedesigns.com

    Other vehicles:

    56 Chevy 2-door BelAir sedan
    56 Chevy 210 4-door sedan
    57 Chevy 210 4-door sedan
    1961 Willys CJ3B Jeep
    2001 Porsche Boxster S
    2003 Chevy Silverado 2500 HD Duramax

  4. #24
    Registered Member BamaNomad's Avatar
    Join Date
    Nov 2016

    Member #:3217
    Location
    Rocket City, USA (Huntsville, AL area)
    Posts
    998
    Those articles were not clear (to me) as to whether they were referencing properties of the 'raw steel' used to make the panels, OR strength characteristics achieved AFTER forming (and then various treatments of the formed part) ??

  5. #25
    Registered Member chevynut's Avatar
    Join Date
    Nov 2011

    Member #:115
    Location
    Fort Collins, CO
    Posts
    9,343
    Unless it's a critical structural car part, heat-treating after forming isn't usually done with steel parts. The properties are engineered into the sheet steel as it comes out of the mill. These modern steels are engineered to have specific properties, unlike the steels of the 50's which were lower quality and lower strength plain carbon steels. This allows different steels to be used for different purposes depending on the strength and formability requirements. You can take a low-strength mild steel and make a stiff structure by design. A high strength steel can be made thinner yet still have the same resistance to deformation as a mild steel due to it's higher yield strength.

    http://www.worldautosteel.org/steel-basics/

    This type of steel is used for exterior body panels:

    http://www.worldautosteel.org/steel-...ase-dp-steels/
    56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension

    You can see my 56 Nomad build here http://www.picturetrail.com/chevynut

    For affordable C4 Corvette Suspension conversions for your car, visit http://www.classicedgedesigns.com

    Other vehicles:

    56 Chevy 2-door BelAir sedan
    56 Chevy 210 4-door sedan
    57 Chevy 210 4-door sedan
    1961 Willys CJ3B Jeep
    2001 Porsche Boxster S
    2003 Chevy Silverado 2500 HD Duramax

  6. #26
    Registered Member chasracer's Avatar
    Join Date
    Mar 2018

    Member #:3718
    Location
    Montpelier
    Posts
    111
    I wish I had the links to it but a few years back I read a report that was talking about the higher strength of automotive bodies today. And while you would always have to question some of the results, the information basically said that if you (and I don't mean this disrespectfully) remove deaths from no seat belts, windshields, air bags, non-collapsible columns and etc that the body of the car today protects us much better than earlier vehicles that basically just folded up on us given the same type of impact crash.

    A bad comparison is that of a high school friend driving a late '57 2 door that did not survive a residential intersection crash that hit him in the passenger door. That car was literally folded in half and he never had a chance. My daughter on the other hand had a similar accident where she turned in front of a SUV with a small sedan on a busy 4 lane highway with a speed limit of 55 mph. Car was crushed up to the console, she walked away. How much force did the metals in those cars absorb and dissipate? I will never know but she now has her own family and my grandson is just 18 months from his driver's permit.
    Last edited by chasracer; 03-07-2018 at 11:42 AM.
    The problem is not the problem.
    The problem is your attitude about the problem.
    Savvy?” ~~ Captain Jack Sparrow ~~

  7. #27
    Registered Member
    Join Date
    Apr 2012

    Member #:571
    Posts
    3,496
    Strength and stiffness are two different things.

    You can move a noodle anywhere you want and it won't break. In a collision there are two basic things happening. One is whether the structure is stiff enough to keep from collapsing BEFORE it actually breaks. This is a function of shape and design rather than metal strength. The second is when the damage is severe enough to actually break, in which case the original stiffness is changed because not all the metal is still connected.

  8. #28
    Registered Member
    Join Date
    Aug 2013

    Member #:1806
    Posts
    260
    Its impressive to see it in slow motion
    https://www.youtube.com/watch?v=fPF4fBGNK0U

  9. #29
    Registered Member BamaNomad's Avatar
    Join Date
    Nov 2016

    Member #:3217
    Location
    Rocket City, USA (Huntsville, AL area)
    Posts
    998
    Today's fenders and hoods are designed with small 'indentations or dimples' every foot or so in the reinforcing or structural backup panels behind, which are a 'weak point', so that when it is hit with sufficient force, those parts 'fold up' sorta like an accordion... basically bending the hood or fender in half or quarters, etc.. which takes out a lot of the energy of the collision before actually getting into the firewall and passenger compartment.

  10. #30
    Registered Member
    Join Date
    Aug 2013

    Member #:1806
    Posts
    260
    I have always used original 1950s metal for replacement panels and patches, but I'm running low on 1/4 panels now so I bought a golden star reproduction quarter for a 2 dr HT, and a sherman USA made quarter. The golden star has crisper lines, a much better wheel opening, and of course it has the flanges. They are both the same thickness as the original, but both are softer than the original. I can actually use my hand as a dolly for the back side and hammer on the front to work out the dents.

    The golden star is about 1/4" short length wise. Although the HT dip is better on the golden star, neither one is good.

    I'm shrinking the panel in areas to make it look better and noticed something very strange. Some areas on the golden star don't seem to want to be shrunk with a stud gun, although the shrinking disc works good. Instead of the target area shrinking, it may be an ajacent area.

    Like I said, they are the same thickness and certainly not HSS, but the metal is different than what was used in the 50s. I understand that a lot of cars have to use these reproductions, but its surprising to me to see repairable panels that some people cut off and replace with the reproductions available today.

    I also bought a repro front fender for an unbelieveable price because it has a few dents, and it is also soft and very pliable.

    I remember when the only thing available was a flat panel with a formed wheel opening, so these panals are way better than that.

Page 3 of 4 FirstFirst 1234 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •