Dry ice for car dings?

A few months ago my car ('91 Honda Civic) was severely dimpled in a hailstorm.

Some engineer friends recently suggested using dry ice to pull the dings out.

Sounds reasonable to me, but does anyone out there know if this really works and, if so, by what principles?

I have never used it, but it’s supposed to work using the contraction of the metal by cooling it. By applying the ice (doesn’t have to be dry ice) to the ding, the metal will contract and pull out the dent.

I think it has to be a very small ding, though.

Sounds like they are trying to see if you are gullible enough to go and buy some dry ice and stick it on your car.

Go and tell them you did and it did work and see what they say or tell them it did not work and now the paint is coming off your car and see what they say.


i can vouch for this one. the way it works is by contracting the metal thus, pulling out the dent. paintless dent removal places use a variation of this, they also heat the other side is if accessable. and yes it has to be dry ice. regular ice isn’t cold enough.


I don’t believe it.

I’d never heard of this before, so I don’t claim any personal knowledge at all. But I did do a search and found the following on the FAQ page for a PBR (paintless body repair) shop called Paint & Colordent in Missouri:

I don’t know how effective it would be, but the tendency would definitely be for the dent to deflect outward, as demonstrated by a finite element model I just ran. If anyone would like me to email him/her the plots from this FEM along the parameters I used/assumptions I made, let me know. A few disclaimers about the model:

  1. This is really rough. I spent about 20-30 minutes on it.
  2. It doesn’t assume any pre-stresses.
  3. This is merely a qualitative look to observe the dent’s behavior.

I have saved myself 100’s of $ in car repairs by using a glaizer’s suuction cup to pull out dents.

This is a large suction cup with a handle attached to it . It is normally used to handle sheets of plate glass.
1st- clean area of dent with cloth & plain h2o.
2nd-place glaizer’s suction cup against dent
3rd-push down to form suction seal
4th-YANK HARD!!!
5th-dent pops out/ save mucho pesos

We have met the enemy, and He is Us.–Walt Kelly

Oh, yes. It works. Best applied to the vehicle when it’s been outside on a warm (preferably HOT) sunny day, as the heat of the metal and the frigid cold of the dry ice cause the hail dents to pop right back out.
As a cautionary note…if the hail was hard enough to fracture the painted surface, you’re in trouble.

BTW, we have various firms in the hail belt (Texas, Oklahoma, Kansas) that charge to remove hail dents using more modern methods. It’s saved totaling out many a hail-dented car.

“There will always be somebody who’s never read a book who’ll know twice what you know.” - D.Duchovny

“…along with the parameters I used …” Geez, I’ve been doing a horrible job of proofreading my posts lately.

It does work, but has limited use. Most effective on dents that are not very deep compared with their diameter. Also, won’t do anything to remove creases in the metal, those have to be hammered.

To see it modeled:

  1. take a beer can and gently push in on the side until the indentation just stays (doesn’t pop back out on it’s own). This represents the relative severity of a dent for which this technique is useful.

  2. Place an ice cube on the center of the dent. (if the can is warmed first, it will work better)

  3. Imagine scaling everything up to the size of a car (with steel instead of Al, and dry ice instead of regular).


Speaking of beer cans, pmh, I need to get on the stick with that buckling problem. I’m going to email the OP’er of that thread to see what brands they were drinking, just to make sure I don’t miss anything obvious (e.g. the pop comes from the island of Fongo-Wongo, where they use steel cans). I can’t stand it anymore, what does “WOTSB” stand for?


beer cans: PLEASE!! It’s still driving me nuts.

WOTSB: Long story.
[MPSIMS]I grew up in a part of the south where we thought “The Dukes of Hazzard” was a documentary. So, naturally, a portion of my wasted youth was spent street racing (ala Bob Falfa, hidden nitrous, cheater slicks, …the whole 9). WOTSB meant anything from “Damn the torpedos…” to “Trust, but verify” to “…dance like nobody’s looking”. Basically, grab life by the throat and throttle every bit of enjoyment from it. NEVER LIFT. Usually used as a parting comment, it is:

Wide Open ‘Till Somethin’ Breaks.

Think of it as No Fear circa 1985.

Thanks for the replys, folks.

For the record, I think dry ice will work: Honda metal is thin, the dents aren’t deep - convection should make the dimples pop out.

However, I think the glazier’s suction cup method is probably easier (and was my first thought after the hailstorm).

In the interest of science, though and for general shits n’ grins I’m gonna try both this weekend.

I’ll post results for those interested in MPSIMS forum Monday or Tuesday.

The skin of a DeLorean is aluminum. :slight_smile: This will be welcomed news to the denziens of "Back To The Future: fans out there…


" If you wanna kiss the sky, you’d better learn how to kneel ".

DeLorean? No, it’s stainless steel.