Popular Mechanics (South Africa)
Underwater power tools
For the first time ever, a cordless drill and angle grinder can be fully submerged. Safely.
Water and electricity can mix
LAST SUMMER, TWO MEN ATTEMPTED TO FIX the busted reel used to wind up and store a pool cover. Although the reel was mounted barely two centimetres over a filled swimming pool, those idiots – my brother, Mickey, and me – decided not to empty the pool. Instead, we wrapped a AC mains-wired electric drill in layers of garbage bags. Our horrified family gathered as we awkwardly attempted to drive a series of screws without accidentally dunking the drill and electrocuting ourselves.
That nightmare is why I was so interested when I heard about Nemo Power Tools, a Hong Kong based company run by entrepreneur Nimo Rotem. This year, Nemo is launching an expanded series of handheld power tools that are completely waterproof; and, in my case, idiot-friendly. They power through any type of water, even contaminated sources, so they’re ideal for a wide range of commercial and consumer uses.
I tested the V2 Divers Edition cordless drill (R11 000) and brushless angle grinder (R18 500) on dry land first. I happily drilled all kinds of holes, drove three dozen 50-mm deck screws, cut pieces of pipe, and ground down some steel scraps I found lying around the house. But I wanted to test them in the deep, too. Since it was too chilly for a swim outside and I was too poor for a quick flight to the Caribbean, I had to come up with an alternative.
When I headed to the bathroom in my 7-mm wetsuit and snorkel, carrying a stack of wood and steel, my wife gave me a look. “It’s only a test,” I said. Both the drill and angle grinder need to be air pressurised with a clever bicycle-style air pump before being submerged. How much pressure depends on how deep you’re working. At only 60 centimetres in my bathtub, it didn’t take long to get to the necessary one bar (nearly one atmosphere) of pressure. If you are working at the outermost depth of 50 metres, you must pressurise tools to a maximum of six bars. Even dunking power tools in the bathtub can be frightening at first. But once the drill started spinning underwater without electrocuting me, the weirdness passed. When you’re finished, you release the air pressure so the tools can be stored. (Excess pressure left in the tool strains the mechanical seal and could decrease its lifespan.)
The 18-volt V2 drill has two bright LED work lights, which is important if you’re in deep water. It has a 12-mm corrosionresistant keyless chuck, offers 16 torque settings, and has dual gear speeds up to 1 500 r/min. That lets you drill up to 10 mm holes in steel and 25 mm in wood. At three kilograms, it’s a little heavier than most standard drill drivers, but underwater you won’t even notice.
As for the angle grinder, it has a 22-volt 5-amp-hour battery to power a hefty 1 500-watt motor. Using a 110 mm-diameter cutting or grinding wheel, the tool achieves cutting speeds of 6 500 r/min when submerged and 9 500 on dry land.
As well as they performed in my tub, Nemo tools are ideal for scuba divers, pool
and spa maintainers, and boat owners; anyone with constant wet work to be done. You no longer need to haul out a boat to dry-dock to clean propellers, hulls or waterlines. Just put on your wetsuit, add the wire brush attachment to the drill and jump in. What used to be a cumbersome job becomes a little less cumbersome. Commercial divers can use the angle grinder for salvaging wrecks or grinding off rusted bolts. Nemo says its tools are also used by rescue divers, fire departments and sewer-repair crews, and in the militaries of ten different countries, including special- forces teams, for underwater construction and aircraft-carrier maintenance. Maybe my brother and I will even use them the next time there’s an issue in the pool. As enjoyable as it was to have such a rapt audience, it’s even more fun to live through the experience.