Bold Projects → Helium and LED Sky Lanterns

I’ve always loved the pictures from sky lantern festivals, with hundreds of floating lanterns lighting up the night sky – and if anyone has ever seen the Disney movie Tangled (with three nieces, we certainly couldn’t avoid it), it’s hard not to have a soft spot for them. Unfortunately, the aftermath of releasing sky lanterns isn’t great for the environment, even using the ones that are labeled as biodegradable. And of course, there’s also the risk of them blowing off course and catching something on fire – which is probably why they’re not legal in many places, including nearly every US state. But I really wanted to release lanterns at our wedding. Luckily, we’re engineers and figured out a work around, using helium balloons and LEDs. In some ways these are even better than the original sky lanterns, because they’ll stay for hours.

Here’s what you’ll need (makes 10 lanterns):

• Qty 10:  White Sky Lanterns (like these from Amazon) – make sure you get large ones
• Qty 10:  36″ clear balloons (like these from Amazon)
• Qty 40: 10mm diffused lens LED lights (we used these from Evil Mad Scientist – it’s important to get the diffused variety, since this will disperse the light in every direction)
• Qty 40: CR2032 batteries
• Qty 10: Sections of fishing line, cut to various heights depending on the altitude you want your lanterns to reach
• Qty 10: Something to weight the lanterns (we used large hex nuts tied to the fishing wire)
• Qty 1: Helium tank

The most important thing with these lanterns is weight reduction – during initial feasibility evaluation, I calculated the lift you get from a given volume of helium to figure out the size of balloon we needed to carry everything required. We ended up needing the biggest sky lanterns we could get (luckily most of them are quite large – there’s a comment on the ones I bought that says “you could easily fit a toddler in these”) and the largest balloons I’ve ever seen (seriously, 1 metre balloons?!?). The lightest weight option for a light source is to build your own by taping an LED to a battery – you can get 4 LED assemblies in each balloon and they’ll still float.

Step 1: Build your LED Assemblies

Tape your LED lights to your CR2032 batteries (the same as they do in this article), similar to creating a throwie but without the magnet (and yes, we skip the resistor…if you’re nerdy like us, you can read about the use of resistors in battery-powered LEDs in this great article).

Step 2: Unfold Sky Lanterns

Your lanterns will probably be pretty flimsy, so you’ll want to unfold them with some care. Luckily it doesn’t matter if there are some tears in them since they’re just an attractive housing for the balloons (this is the main source of negative reviews for these online – that they’re too flimsy and tear).

Step 3: Insert LEDs

Stuff four of your assembled LEDs into a balloon – we found this to be an optimal number for providing nice light but still allowing good flotation that lasts for a couple of hours.

Step 4: Inflate Sky Lantern

Place the LED-filled balloon inside a sky lantern, then blow up the balloon with helium until the sky lantern is full (pay attention when you’re blowing up the balloons, since the balloon’s capacity is larger than the sky lantern’s, so you’ll tear the lantern if you overfill).

Step 5: Anchor Sky Lantern

Tie off the balloon, then attach your fishing line and weight (don’t forget the weight…you don’t want to be that kid who’s crying as your balloon sails off into the distance).

Step 6: Enjoy!

Your lantern is ready for release! If you’re super into the whole “we must have a mass release” thing, you can create secondary anchors so they stay on the ground as you finish making the other lanterns, or pass them out to guests to hold until the release.

Bold Projects → Helium and LED Sky Lanterns