Whether accidents are slightly humourous or of grave concern, great care must be taken with things that spark.

There are chemicals used regularly in a bike shop that are combustible, corrosive, and potentially explosive, and numerous sources of ignition — welders, battery chargers, grinders — that can set them off. It’s prudent to keep these things apart. When I was a service tech, I had seen several times how oversight, negligence, and downright stupidity often caused these things to come together unintentionally with a resulting big bang.

Some blasts were unpredictable, like the time when Marc, a fellow mechanic in a Honda shop I worked at in the early ’80s, unintentionally blew himself out of a sidecar. Marc had been tasked with prepping a new Velorex sidecar for installation on a bike. Aside from installing the wheel, windshield and mounting hardware, he also had to glue the carpet to the interior of the sidecar using contact cement. This process created a lot of fumes in a semi-enclosed, poorly ventilated space. Those volatile fumes were highly flammable (and quite toxic), but what was missing for launch was a spark. Well, Marc provided that spark when he began drilling a mounting hole while sitting in the freshly carpeted sidecar. The spark from the drill’s motor ignited the fumes, causing a blast that catapulted the hapless tech about two metres into the air and onto the floor. Aside from being terrified, he only sustained some bruising. After about three seconds of initial shock, the rest of us laughed and laughed.

When I later moved to a Harley shop, I began working with Sam, an old-school mechanic whose mantra was “What’s yours is mine and what’s mine is my own.” Being of an older generation, Sam didn’t have the keenest safety sense. We would repeatedly tell Sam to turn on the exhaust fan whenever he was filling or charging a battery at the battery station; he would just mumble and grumble. Inevitably, one day, we heard a loud blast and a guttural scream in the shop. In the process of placing his personal car battery on charge, said battery exploded, spraying Sam from head to toe with battery acid. Fortunately, Sam wore eyeglasses, which protected his eyes, and the battery station was conveniently located next to the wash bay, where a bike was being washed. Sam ran into the wash bay and the bike-wash guy proceeded to pressure-wash poor old Sam. Sam never told us if he had taken off the battery’s filler caps before charging or if they had blown off, but we figured it was the former. He never left that exhaust fan off again.

Another time, at that same Harley shop, we were on the morning break in the canteen when we felt a pressure wave that rattled the huge fire door separating the canteen from the shop. Startled, we slid the fire door open only to be greeted by the smell of burnt oil and thick, blue smoke. Then we saw Red, who got the nickname due to his tightly curled scarlet locks, speed-walk by us toward the bathroom, his face as red as his hair, and smoke wafting from his head and shoulders.

He had gone to drain some used oil into a 200-gallon drum that had a hole cut into it for that purpose, and had also decided to check on the level inside the drum, when it mysteriously ignited. He immediately went home, but came in the next day nonetheless, sporting a fresh crew cut and a face lathered in ointment. We asked Red what had happened and he said he didn’t know: he went to check on the oil level, and the tank exploded. The blast actually blew out the sides of the oval drum, expanding its volume by probably another 50 gallons.

Now, Red had trust issues — every socket, screwdriver handle and air tool in his tool box (and that, too) was engraved with “Red.” Even his cigarette box had his moniker on it. We were suspicious about how the used oil, which also contained a fair amount of gasoline, could have ignited. A couple of days later, we had our answer: the janitor was making his rounds with a broom, and among the sweepings was a shiny Zippo with “Red” engraved on the side.

Early in my career as a tech, I, too, experienced a blast. I had to weld a gas tank, and took what I thought were appropriate precautionary measures by thoroughly washing it out with soap and a pressure washer. A test flame at the filler neck proved my procedure to be a complete failure, as the fumes inside ignited, blow-torching an eyebrow clean off. I’ve since learnt to run exhaust from a running engine into the tank until it is hot to the touch, thus neutralizing the fumes inside and making the tank blast-free.