,
Now let's move on to a much more real situation. Here is the door of this guy's car after a not so great driver gave it a bit of a massage with their bumper. Pretty bad.
No good way to fix it without going full tilt and painting the panel. I'd rather spend that money on the Starletabusa so it's a home repair hack job or nothing. As with many things there is a big gap between what happens in the lab and what happens in the real world. Just tapping on the high spots around this huge dent won't bring it up because the door of the car has edges and the size of the door can change. This means that if you smack the high spot near the dent you are just expanding the overall dimension of the door itself. It's as if you cut the can in half long ways before trying that finger fix we did earlier. Now what?
Hey, that's a clever item! It's a body workers suction cup; they cost $20 at your F.L.A.P.S. (Friendly Local Auto Parts Store) and they don't work. That's right, unless your car is made of beer can that suction cup won't pull any dent you would ever care to pull. It should though, as it has a 5 inch diameter and that makes for an area, Pi*R^2 of about 19 square inches. Even more good news is that we live in a world where atmospheric pressure is just about 15 psi. Without that constant pressure our eyes would pop out and our blood would boil. Gross.
OK so 15psi x 19sqi = a bunch (285 lbs). This means that if you could get all the air our from behind that rubber cup you would have 285 lbs of pulling force. That's more than enough to move most dents out. The problem is that the cruddy rubber the cup is made of deforms and allows air to leak in just as you start to get results. The trick is keeping the air out of the cup. Enter the butyl.
If you don't have a roll of this stuff go to an auto paint supplier and get some. It's incredibly handy for any number of sealing tasks. Removing a taillight lens? Seal is back up with butyl! Door panel loose and rattling? Stick it back with butyl! Dent the dome on a speaker? Pull it out with a glop of butyl (this really works B.T.W.)! Run out of chewing gum? Go get more gum, butyl is made of petroleum and that's not good for you. Here's what it looks like when you buy it:
Now that we have established a good seal around that rubber cup, we can pull on the dent and get the metal back to its normal shape. Problem is, that if you just pull on the dent all that will happen is it will recede once you release the force. What? Here's the thing, the high spots next to the dent are still a key element to fixing our problem. In order to make the dent stay out one needs to push the high spots next to the dent back in and unfold the metal at that spot. Sadly, this is not an exact or perfect process. After several “pulls” on my dent I got it a whole lot better but pretty far from perfect. As I pulled on the dent with the suction cup I also pushed on the high spot above the dent to help un-kink the metal there and force the dent to stay out. It's a pretty effective method and could yield really good results if your dent was not so bad as to have stretched the metal like this one had.
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Curing a section of sheet metal that has been stretched out is not a paintless process as it requires heating and cooling the metal with a torch and using a device called a shrinking file and some special hammers and stuff.
The last step is to get some high quality rubbing compound and clean all the scuffed on rubber and paint left behind by the car, pole, tricycle, wheelchair, or whatever it was that got shoved into your car. This compound in the picture is really great as it's designed to be used with a range of buffing cloths from rough to fine. With the finest cloth like a micro fiber it leaves a perfect finish but when used with a wool buffing wheel it can cut through up to 1200 grit sandpaper scratches. One simply changes the type of buffing cloth from rough to fine in order to work up to a polished finish with no swirl marks. Very handy.
In closing, while I have to admit that this repair is not perfect and I'm living with a wavy door for now, at least it's not “point and laugh” bad anymore.
