The Black Scrolls of Sam

Homemade lava

I have been interested in volcanoes for a very long time. I've always thought they were fascinating.
My favorite volcano is Kilauea, on the southeast side of the big island of Hawaii. The volcanoes in Hawaii are shield volcanoes, meaning that they probably aren't what you picture when you hear or read the word "volcano." Instead of steep cones, they form wide mountains with shallow slopes. This is because the lava they erupt is much more fluid (although still much thicker than what many people imagine) than that of steep-sided volcanoes, so it travels farther from the vent and builds up a broader, flatter mountain. Explosions are usually rare with shield volcanoes.

The steep sided volcanoes you are thinking of are called stratovolcanoes. These include Mount Saint Helens, Vesuvius, Mount Rainier, and Mount Fuji. They have steep sides because the lava they erupt is usually much thicker than that of shield volcanoes. Often, they don't erupt lava at all, but volcanic ash. Volcanic ash is not like fire ash. It's made from bits of rock, rock dust, and shards of glass. A lot of it lands close to the vent, which is another reason for the steep sides.

Anyway, back to Kilauea. It's been erupting almost nonstop since January 1983, and probably won't stop anytime soon. The eruption began with a side vent on the volcano's flank, and the eruption there continues to this day.
Another eruption started at the summit in 2008, forming a lava lake deep within the crater. This has also ongoing, but usually too deep in the crater to see.

Now, we're starting to get to the point of this story. Kilauea is renowned for having some of the most accessible lava flows in the world. Since they're small, slow moving, and generally not that dangerous if you use common sense, people were often allowed to go right up to them. This is one of the biggest draws to Hawaii Volcanoes National Park, and it's something I've wanted to do for a long time.

But not right now. The only current lava flow is beyond the boundaries of the park, and in a forest reserve. Thanks to those d**n safety zealots, (we've all encountered them,) all of the lava is closed off to the public, on pain of arrest.

This made me so angry when I found out about it, and still does. Unless it's flowing into the ocean, lava viewing is not actually very dangerous. (Hiking across miles of cooled lava to get to it can be, but people can and do still hike out there, but they can't see molten lava anymore)

Someday, the lava will probably flow into an area where they'll let people see it again, but so far there's no sign of that happening. In the meantime, there is not a single drop of publicly accessible lava anywhere on the island. I live in an undisclosed location (sorry, stalkers!) very far from Hawaii. I have not yet gotten the opportunity to go there. If I did, it would be a very rare opportunity. I would not waste this opportunity by going when all the lava is wasted being where I nor anyone else can see it. This is an economic problem as well, because lack of viewable lava deters visitors like me, and guided lava tours provide more jobs for small towns.
I understand that a visit to the park would be really cool even without the lava, but since seeing molten lava up close is my number one reason for going there, and going there would be a very rare occasion, I'm not going if I can't.

I realized that I probably wouldn't be able to go for a long time anyway, but the anger about the safety zealots keeping people away from the best part of Hawaii continued to fester in my mind.

I decided to do something about it. Even though I knew it was a really long shot, I looked up ways to create lava at home. I wasn't expecting too much success, but lo and behold, I found something I could actually do!

There's a special kind of lens called a fresnel (the s is silent) lens, named for the French got who invented it. It uses a series of concentric ridges to focus the light, so it can be quite wide and yet stay flat and not bulky. They were originally invented for lighthouses, but more recently they've been used in overhead projectors and rear-projection TVs.

People have discovered that if you get the right kind, (one that focuses the light into a spot and not a line,) a large fresnel lens can focus sunlight to melt rock into lava.

I went on eBay got an 11 inch square lens meant as a replacement part for an overhead projector. It turned out to be two lenses held together face to face. I split them apart, so now I have two lenses that work very well. They can turn an area of dirt, sand, or certain kinds of rock up to a quarter inch across into lava.

That was awesome, but I decided I wanted more. I ordered a 26 by 35 inch spot focus lens from an old TV, and it's amazing. It creates about a square inch of lava, and had some success baking a potato. The picture at the top was made with this lens, in a little dirt volcano I built in my backyard. It will work even better when build a frame and swivel mount for it so I don't have to hold it up.

I'm still a kinda angry about all the lava in Hawaii being locked away, but this is making me feel a lot better for now. I can hardly get over how awesome it is that I can make my own lava in my backyard!

Want to do this yourself?
Always wear sunglasses, and never look directly at the focal point except when focusing it and checking every now and then to make sure it stays focused.
Be sure that the grooved side of the lens is facing the sun, otherwise it might not work.

Always store the lens wrapped up in a safe location away from sunlight. Be very careful when using it; it will set wood on fire almost instantly and can cause severe burns. I accept no responsibility for any damages caused by doing this.

The overhead projector lens cost me $9.50, plus shipping. Not bad.

Large spot lenses are getting rarer nowadays, since TV's haven't used them for several years. They usually cost hundreds of dollars, but I got mine for $60 because it's a little scuffed up. If you want to melt rocks, make sure you're getting a spot lens. Linear lenses (which focus the light into a line instead of a point) are much cheaper, but can't generate temperatures over a few hundred degrees. Still great for cooking, though.

Once again, be careful! Good luck, future mad scientists, and happy 4th of July!