dry ice

[SS69]

ive heard a few times that dry ice can be used to get minor dings out of cars. is this true? if so how is it done? and if not, is there anything i can do to get very minor dings out of my car without having to pay someone else to do it?

 

[Z32]

never heard of that but dry ice is used to remove sound deadening (black tar crap)...

 

[icandriftbetter]

yeah this is a new one to me, i cant see how it would though

 

[Joey D]

I've heard of this before, but I don't know whether or not it's actually true. I would like to know though.

 

[E55Power]

Hmmm....it makes sense. With it that cold, it would pop a dent back out.

 

[sicbeing]

...? What does temp have to do with getting dents out?

 

[emad]

Metal contracts when it's cold. I guess the idea is that the cold would cause the metal to pop back in place? Somehow I doubt the effectiveness of it though.

Edit:
http://www.vintageairstream.com/rr_topics_dents.html
scroll down a bit

 

[Joey D]

I think this might be a good Mythbusters thing to test.

 

[Duke]

I've heard of packing your carburetor in dry ice, but I've never heard of it being used for bodywork. It's certainly possible that I've just never heard of it, though.

 

[icandriftbetter]

yeah the link emad posted was pretty cool. guess it is true

 

[JNasty4G63]

I've seen this work actually. Not with dry ice, but just regular ice water. The dents have to be fairly fresh, and the panel needs to be hot. My buddy left the car in the sun for a while (summer), and then we heated it up some more with a heat gun. Nothing drastic to keep from scorching the paint, but nice and hot. Then just pour some real cold ice water over the dent. The extreme hot to extreme cold can make the metal return to its original shape.

It didn't just pop right back to new, but it thumped and creaked fairly loud and did come out a little. You can still see a slight, little wave in the paint if you look real close, but otherwise you can't tell. He used to detail cars, and says this doesn't work all the time. But, if the dent is still fresh and not settled in, it can work. I didn't believe him, but I saw it first hand, and it worked for the most part. He says it won't work on old dents, or real big creased type dents. But, just a small, fresh dent can come out.

Hilg

 

[somebody]

I've never heard of dry ice removing dents but I know that some high-tech repair shops are looking at using it for paint stripping. They use it instead of sand for blasting the paint because there is no residue left over to clean out. I don't know if they will use it commercially but this is how some aircraft maintenance places now do it.