quarter pannel install questions

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1966 dart wagon

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i have a question, when my dad did his challenger pannels he over lapped(sp?) the pannels and the new pannel sat on the body line, (instead of smoothing a straight spot) well on mmm(mopar mag) they had a article on how they do installs of these pannels and they did a but weld around the body line and around the door jam to make it appear as if nothing ever was changed, but with the new metal u get now days isnt as thick as factory, and with a but weld isnt that not very strong, especially for my plans of auto crossing(road racing) and drag racing my car in the future, i dont get why they would show u to do it this way when there is a way to do it to make the pannels so much stronger, and the use of filler is a must in both cases anyways, i dont really get why they would tell you to do it this way.

mopar mag pic

below is the closest pic i could get of the pannel(i had to go to school and he didnt take any photos while i was gone) anyways why would u do the but joint sure i guess it gives a better factory look but its weaker, and i would presume you would have alot of 'blow threw' cause the metal is so thin? just a question ive been pondering, cause im gonna do this shortly to my cuda

pannel.JPG
 
A butt weld if done properly is just as strong if not stronger than the surrounding metal. Some people use a flanger so where the panel overlaps the outer panel is not slightly higher that the panel it is covering. There are many ways to attach replacement panels and I would say it is mainly the preference of the person doing it more than one way is more right than the other. The main reason for using the body line is that the warpage will be easier to control than welding in a flat panel area. The thing I will add about overlapping is that moisture and dirt could collect between the panels and eventually help corrosion. If you do any metal work and you can't get to an area to apply a coating of some sort after welding use a weldable primer or coating before you weld.

From your picture it looks like he did a fine job.
 
Another problem with lap welds is the metal is efectively thicker where the lap occurs. This can lead to problems later on when the panels heat up in the sun and expand and contract. Basicly the metal expands at different rates and sometimes the seams can become visible. A butt weld is more likely to expand and contract at the same rate as the original panel. Once you learn how to butt weld in a quarter and control the warpage it is the only way to go.
 
Easiest way to control warpage when doing sheetmetal, butt weld or otherwise, is to use T.I.G., but that also requires someone talented with T.I.G. to acomplish it. My instructor when I went to school for welding technoligies told us that the person who can butt weld two pieces of aluminum foil together with no filler metal used in the T.I.G. process, can do anything and ask any wage. I also like T.I.G. because you can do it with a nice heavy T shirt and some good SPF 45 sunblock on. No spatter, woohoo!.
 
I like the over lap joint, the key is to use LEAD for the filler as it will wick in behind the joint effectively sealing out the moisture. A little seam sealer on the inside for some added insurance and it should last a long time.
 
so just putting some fiberglass over the weld seem(lap weld) is not good enough, i should use lead AND fiberglass, isnt lead bad for you and bad to use/breath :-|
 
I've done some sheet metal welding, but always used panel overlap. I never considered butt welding because I didn't think it would be strong enough, due to my welding skills. If the welding is done high up enough on the qtr panel, wouldn't that mitigate any warpage factors, and be less prone to rust??

Howard
 
my cousin told me if i was going to lap the quarter panels on my duster to try and lap it on the inside of the old quarter that way water will run off and can't fall behind...And he did go to college for body work and worked on alot of old cars.
 
1966 dart wagon said:
so just putting some fiberglass over the weld seem(lap weld) is not good enough, i should use lead AND fiberglass, isnt lead bad for you and bad to use/breath :-|

Actually, you shouldnt need to use any fiberglass. Just Lead followed by the body filler. The process is much like sweat soldering a copper pipe or soldering an electrical connection. You're just using a larger block of solder and a larger heat source. You can find lead , the tools and an instructional video at www.eastwood.com I bought the middle of the road kit.
 
DodgeFreak said:
my cousin told me if i was going to lap the quarter panels on my duster to try and lap it on the inside of the old quarter that way water will run off and can't fall behind...And he did go to college for body work and worked on alot of old cars.

If you were fixing the roof on your house, I would worry about which way things overlap. On a car , Using lead (outside) and seam sealer (inside)... I would say overlap it to obtain the best fit. :toothy7:
 
For you guys that don't think you weld good enough to butt weld why do you think your welds will be better with the overlap? If you are not good welders overlapping won't make you weld any better.

Krabysniper, TIG welding produces more heat that MIG does. It's basicly oxy/acetylene gas welding with an electric arc flame. This is why you do not get any spatter like you mentioned. Just the same as if you are oxy/acetylene gas welding (no spatter). It's not to say that a good TIG welder couldn't control warpage it's just not easier than MIG. Before I purchased my MIG & TIG welders years ago I used a oxy/acetylene welder on all of my panel work. It can be done, it, like other things in life takes practice to achieve good results.
 
340mopar said:
Krabysniper, TIG welding produces more heat that MIG does. It's basicly oxy/acetylene gas welding with an electric arc flame. This is why you do not get any spatter like you mentioned. Just the same as if you are oxy/acetylene gas welding (no spatter). It's not to say that a good TIG welder couldn't control warpage it's just not easier than MIG. Before I purchased my MIG & TIG welders years ago I used a oxy/acetylene welder on all of my panel work. It can be done, it, like other things in life takes practice to achieve good results.


340 is correct. TIG puts more heat into the metal then MIG. This should actually lead to more warping. The real advantage of TIG is the metal is not hardened as much after welding as it is with MIG. Tig welds can be easily hammer and dollied while MIG welds are often hard to work and can be brittle. On the other hand if you are careful with the MIG there will be little to no warpage when done correctly.
 
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