Why does new sheet metal need filler?

[BruteForce]

Ok, I'm going to ask a stupid question. Why, when one buys new quarter panels or whatever, and puts them on, one has to spend hours sanding and filling with bondo? The factory certainly didn't need to do that, and the body panels are straight. Is it because the manufacturer of the new sheetmetal can't seem to stamp them out straight? Or they cannot be put on straight, or what?

[bbscamp]

The new metal is thinner, and pretty wavy.  There is also quite a bit of distortion when fitting them up, AND then welding them in.  Putting new metal on isn't done exactly in the same way the factory did it.  Factory is pretty much all spot welds which holds down distortion somewhat.

OEM panels are pretty darn wavy if you look at them.  Most cars resto'd today are WAY WAY WAY better than the factory every produced.  Mopar panel/hood gaps that varied from 1/16 to 1/4" weren't too uncommon.   Have a resto shop put their name on  job like that now?  they would be out of business pretty quick!  M@@co and Earl Shiebe(?) are probably closer to factory jobs than any other shop!!   

[elitecustombody]

I'm with bbs, exept I didn't know the new sheetmetal is thinner, if you look at alot of brand new cars and stick block them,you will also see plenty of waves and imperfections,I remember mid 90s Fords,every panel looked like it was bulging out right in the middle ,

most likely the replacement panels is not properly fitted and is distorted because of misalignment,plus you need to keep in mind most of the replacement sheetmetal comes from China ,which is known for cheap,parts,which are made out of softer steel
 
 Stefan   

[Ross]

My Goodmark parts all say made in Taiwan on them...
'Nuff said...

[BruteForce]

Most cars resto'd today are WAY WAY WAY better than the factory every produced.  Mopar panel/hood gaps that varied from 1/16 to 1/4" weren't too uncommon.

After reading that, I went down and took a hard look at my Challenger. It still has the original factory black paint on it, as far as I can tell. The panels are on straight, the gaps even, and looking at lights reflected off the paint, it's pretty darned straight. There's one spot where the left quarter looks poorly joined to the roof pillar, but that's it (I suppose that might be a poorly done repair, too.)

Certainly, the car has never undergone a resto. I bought it from a couple of kids in '87 and nobody invested a lot of money in them back in those days, and mine was not one of the desirable combinations (then).

[73Chally]

Sounds like you got pretty lucky.  Mine went through a repaint 14 years ago, and when you look down the sides it's wavy as heck.  It was real noticeable when it was up on a flatbed at eye level.  Not sure why the different perspective made such a big difference, but it did.

[BruteForce]

I agree I got lucky. I enjoy reading the threads where people are restoring utter disasters of a car, but it makes me realize that if I wrecked my dodge, that would be the end of it for me. I can't afford a restored one, and the unrestored ones are way too far gone.