Melting Holes

As I've sown the over wintering onion bulbs in vending machine cups and have used all the ones I have ready, it's time to get out my trusty soldering iron and melt two drainage holes in the bottom of the next batch of vending machine cups, ready for the coming growing season.

I have found that if I stack them in 4's the hot bit is long enough to penetrate and melt the holes quickly and efficiently.