Dent removal in a confined space

[Schwinny]

I was looking at a near perfect vintage headlamp and the only thing wrong with it in any way is a pinky nail size dent on the underside. Out of the way and cant be seen unless you look up from underneath. A spoon would probably do fine to push it out, but it had been there a long time and was next to a rivet holding on an internal part so not easy to get a good angle on.
I thought back to a way Ive know to take care of dent like this with no marks and nearly a perfect removal sans any divit at the strike point that may have been created. The dent will be gone.
This will work on bicycle tube dents. May even help to straighten a frame.

Many folks dont know about this technique but it is nothing more than a high school science experiment.
Water expands, If there is a dent in something such as a tube or hollow like a can or bowl, you can just fill the void with water and as the water freezes, it will expand the metal back to its original formed shape without marks. the more confined the space the more pressure will be exerted, but it will take from 4 to 20 times in the freezer.
Ive got the headlamp in there on its 5th freeze cycle now and about half of the dent is gone.
I will post a before and after pic when its done.

Fingers crossed.....

Before pic is the best of 8...uhg.

 

[Gordon]

I have heard of people removing hail dents from their vehicle by letting the affected area warm up on a hot sunny day and then placing an ice cube in the dent. Supposedly the temp change causes the metal to contract. I have no idea if this really works or if it is just a story.

 

[1motime]

Very interesting idea! Please post some photos

 

[saladshooter]

Wouldn't the "pressure" take the point of least resistance and expand into whatever opening is present?

I was looking at a near perfect vintage headlamp and the only thing wrong with it in any way is a pinky nail size dent on the underside. Out of the way and cant be seen unless you look up from underneath. A spoon would probably do fine to push it out, but it had been there a long time and was next to a rivet holding on an internal part so not easy to get a good angle on.
I thought back to a way Ive know to take care of dent like this with no marks and nearly a perfect removal sans any divit at the strike point that may have been created. The dent will be gone.
This will work on bicycle tube dents. May even help to straighten a frame.

Many folks dont know about this technique but it is nothing more than a high school science experiment.
Water expands, If there is a dent in something such as a tube or hollow like a can or bowl, you can just fill the void with water and as the water freezes, it will expand the metal back to its original formed shape without marks. the more confined the space the more pressure will be exerted, but it will take from 4 to 20 times in the freezer.
Ive got the headlamp in there on its 5th freeze cycle now and about half of the dent is gone.
I will post a before and after pic when its done.

Fingers crossed.....

 

[Schwinny]

Wouldn't the "pressure" take the point of least resistance and expand into whatever opening is present?

Yes, that's why the more confined the space, the more effective it is. This headlamp may take 20 cycles or more.
Take a coke can, pop it, empty it. Then dent it and fill it with water. Put it in the freezer and when completely frozen. The expansion will have pushed more of the dent out rather than going up and out the small pop-top hole at the top.

I learned this in the seventies in a newsletter in the Beer Can Collecting Hobby. I dont do that anymore, but I took several dings and dents out in those days. And one time when driving my motorcycle up a plank and into a moving truck, the plank dropped from were it need to be to nearly a foot below as I was driving in. The BRAND NEW header was pinched in half. ( I bought them on a credit card that consequently had a policy were I got my money back on that header). Some time after we got where we were moving and my claim was settled, I remembered the trick and that header went back to working without being replaced, You could see a line and small divet across the tubes but they were completely opened up. They were later wrapped for drag racing so it didn't matter much.

 

[Schwinny]

Update...
First, I notice there is a Topic header below that would fit this better. So if this should be moved, please do.
Second, it looks like the ding is about 3/4 gone at this point. Im at freeze cycle 13 so it ay take a month or two the way I forget its in the freezer....