- Get a thin sheet of tissue paper, the kind you use for wrapping gifts.
- Make sure the room is relatively quiet and the mattress is full.
- Lay the tissue paper on the mattress and let it rest. If the hole is under the paper, it will make a very audible hissing noise.
- If you don't hear any hissing after a few seconds, move the paper to cover another area.
- Flip the mattress over and try the other side.
- Then stand the mattress up on its edges and cover the edge with the paper, moving and rotating until you have covered the whole mattress.
- For the corners, just hold the paper in place in a way that tightly covers the corner.
I have an expensive air mattress with built-in pump and velvet top with a hole it it, so we didn't want to use water or soap on half of the mattress, and none of the other methods worked.
Other methods we have seen documented:
- Dunk the mattress under water and look for bubbles. With the velvet top, and built in pump, we didn't want to do this completely. We tried putting water over small areas, but not effective.
- Cover the mattress with soapy water and look for bubbles. Same problem with the velvet side, even worse. Also incredibly messy, cleanup is slow and annoying.
- Coat with powder, look for puffs. Didn't want to try this because it would be very messy.
- Fill with smoke or otherwise colored air. Tried this, but difficult to get enough smoke in with the built-in pump. Was not able to see any smoke come out of the hole after we found the hole.
- Listen to the air mattress. It was a very small hole, couldn't hear anything without tissue paper.
- Feel around for air. It was a big mattress, hard to find the hole.
