How To Undent A Ping Pong Ball: Step By Step Guide

The worst thing during a game of table tennis is when someone hits the ball a little too hard and it gets a dent. Especially if that’s your only one… But, there is hope as it is sometimes possible to repair it and get it back to its former glory.

In this post, we’ll walk you through step by step how to undent a ping pong ball. Sadly though, these methods won’t work if your ball is cracked. Those are beyond repair. If you need some new ones check out our best table tennis balls post here.

Do you want more advanced coaching?

- 20+ Hours of Training
- From Beginner to Master
- Coached by Chinese National Champion

JOIN NOW

The Hot Water Method

The hot water method is the easiest way of getting a dent out of a ping pong ball. It’s also the way thats used to get dents out of other things like cars.

With ping pong balls however it works by heating the air inside the ball which causes it to expand. You only need some boiled water and a cup, the relationship between pressure and temperature will do the rest.

Instructions

Step 1 – Boil some water in a kettle until bubbles appear and pour it into a medium-sized cup.

Step 2 – Drop your ping pong ball inside the cup make sure to avoid putting it directly in the boiling water as it may get damaged.

Step 3 – Get a spoon and push the ball down slightly below the water. This will increase the pressure on it causing the air inside to heat faster and hopefully remove the dent quicker.

Step 4 – Now use the spoon to take the ball out of the water but make sure you don’t try to take it out with your own hands as the water will still be hot and can scald your hand.

Step 5 – The last step is to let it dry. You can use a towel or hang the ball inside a tissue for a few minutes. Don’t let it dry on a hard table as the heat can cause the dent to form again.

The Results

If you’ve done it right and the ball wasn’t too dented you should now have your ping pong back to being able to bounce. It’s worth noting though the ball will not be as good as a new one as the heating may affect its roundness.

You might find that it won’t bounce as much as it used to either but it should last a bit longer and give you a few more good rallies.

The science behind It

If you’ve tried the above method it can feel a bit like magic as the dent magically pops out and disappears. Sadly, no sorcery is at work though and it’s just some simple physics.

As the air particles inside the ball get heated up they begin to expand. This changes the pressure inside the ball and begins to put pressure on the dent and cause it to pop back into place.

The hairdryer method

We recommend the above method but if it doesn’t work for you you could also try the hairdryer method. All you need is a hairdryer and towel (to hold the ball).

Be careful with this method though as you can burn your hand if you don’t use a towel.

Simply hold the ping pong ball in the towel and point the hairdryer at it on a high heat. This has same affect of heating up the air particles inside the ball causing the pressure to change and pop the dent out.

For a bit of fun, can also try it without holding the ball!

If you notice the ball getting too hot or getting deformed, turn the dryer off for a bit and let the ball cool down before trying again.

After you’ve finished and the ball is fixed, you may need to suspend it in a tissue, as mentioned in the boiling water method if it’s too hot.

The thumb method

If the above methods don’t work there’s one more chance to save your ping pong ball which is the thumb method. It’s not very glamorous and just involves using your thumb to push the area around the dent to try to pop it back into place.

This won’t work every time and sometimes you can actually cause the dent to get bigger so this is more of a last resort method. Still, it’s worth a shot.

Why does heating the ball work?

Physics may be a headache to learn at school but it can be really fascinating especially in the context of table tennis. As we mentioned earlier, the heating methods are all to do with science and and equation between pressure, volume and temperature.

This article explains the equation of pressure x volume is proportional to temperature and how that can help us fix our ping pong ball.

When This Won’t Work

Again, as we covered earlier, these methods won’t work every time. If your ball has a crack in it you will not be able to repair it and will have to buy a new one. We can’t change the air pressure inside the ball if it has a crack as it will just leak out.

The second case where you’ll need a new ball is if it has a deep dent. If it’s too deep you can have a go at the above methods but sometimes it will be impossible to repair.

Summing Up

We hope that one of the methods above works for you and you can get back to playing. We recommend the boiling water method as it’s the fastest and has had the best success rate for us. If you have any other ideas for how to un-dent a ping pong ball post them below.