Within the past two months we’ve covered two separate incidents of 3D printing-related fires. One was caused by an ill-advised attempt to smooth a print with acetone heated over an open flame, while the other was investigated by fire officials and found to have been caused by overuse of hairspray to stick prints to the printer bed. The former was potentially lethal but ended with no more than a good scare and a winning clip for “Hacking’s Funniest Home Videos”; the latter tragically claimed the life of a 17-year old lad with a lot of promise.

In light of these incidents, we here at Hackaday thought it would be a good idea to review some of the basics of fire safety as they relate to the home shop. Nowhere was this need made clearer than in the comments section on the post covering the fatal fire. There was fierce debate about the cause of the fire and the potential negative effect it might have on the 3D-printing community, with comments ranging from measured and thoughtful to appallingly callous. But it was a comment by a user named [Scuffles] that sealed the deal:

“My moment of reflection is that it’s well past time I invest in a fire extinguisher for my workstation. Cause right now my fire plan pretty much consists of shouting obscenities at the blaze and hoping it goes out on its own.”

Let’s try to come up with a better plan for [Scuffles] and for everyone else. We’ll cover the basics: avoidance, detection, control, and escape.


The hacking lifestyle is full of “do not try this at home” moments. We routinely play with high voltages, open flame, high temperatures for soldering and welding, volatile and flammable solutions — and sometimes all at once. When you’re in the zone on a build, you may not notice the stray datasheet that fell across your soldering station, or the fact that you’ve plugged one too many instruments into that power strip. All it takes is a second for a situation to go very bad.

Case in point: back in grad school, I showed up late one night to the lab to tend an experiment. As soon as I unlocked the door I knew there was trouble; the scent of burning plastic hung heavy in the air. I investigated further and found a smoking puddle of molten packing foam lying around a Bunsen burner on one of the benches. Apparently a fan had started automatically and dislodged the foam from a shelf; it wafted down and landed perfectly on the burner which had been left on by our technician at the end of the work day.

It was the perfect storm of factors, and only by chance was I there to intervene and prevent the fire from spreading, but it illustrates a few important points:

  1. You need to do a safety audit of your workspace on a regular basis. Make sure nothing can conceivably cause fuel to be exposed to heat in the presence of oxygen — the basic recipe for fire.
  2. Open flame and high temperatures require extra vigilance. Go ahead, be paranoid – check everything twice or three times before leaving the shop. Take a play from the commercial pilot’s handbook and make a shop shutdown checklist if you have to.
  3. Keep your head in the game. My erstwhile colleague nearly burned the lab down in a moment of distraction. It was absolutely understandable in retrospect — he was going through a divorce at the time. But when you’re tired, sick, or emotionally compromised, it’s probably not the best time to be in the shop. Be safe, go read Hackaday instead.


Most modern smoke detectors are wired to mains or have a sealed 10-year battery

Smoke detectors are almost universally required by building codes, and you’d think that more than 40 years after being widely and cheaply available to the mass market that there’d be no dwelling without at least one. Unfortunately, that’s not the case, and newspapers run sad reports every day quoting a fire marshall as saying, “There were no working smoke detectors in the house.”

Make sure your shop is covered by at least one working smoke detector. If like many of us you’ve been relegated to the basement for your hacking activities, don’t rely on smoke detectors on the upper levels to do the job, install one nearby. If your shop is in a detached building, you’ve got the extra problem of being out of earshot if the alarm sounds. Consider a WiFi-enabled smoke detector, or hack one together yourself. You can even IoT any smoke detector by simply adding a smart battery.

Fire Control

Despite your best efforts at prevention, you might face the day when a fire starts in your shop. This is not the moment to realize you have no means to fight the fire. You need to have the tools and the training in place long before the need arises.

You need a quality fire extinguisher suitable for the types of fires likely in the home shop. A quick review of the classification of fires:

  • Class A – Ordinary combustibles like wood, paper, trash, and plastic
  • Class B – Combustible liquids like gasoline, oils, or solvents
  • Class C – Fires in energized electrical equipment
  • Class D – Combustible and reactive metals like magnesium, lithium or titanium
New 5-lb ABC fire extinguisher for my shop.
Ansul Sentry 5-lb ABC fire extinguisher I just purchased for my new shop.

There’s also a Class K for cooking oil fires, but unless you’re hacking a turkey fryer that’s probably out of scope for the home gamer. In most cases you’ll be in the market for a Type ABC dry chemical fire extinguisher, in the 5- to 10-pound range.

Do yourself a favor and don’t buy cheap. A fire extinguisher is a life safety appliance, and that’s no place to economize. In general, the fire extinguishers available at big-box stores are junk. Rule of thumb: if the valve head is made of plastic (like in the banner image of this article), it’ll leak. Spend a few bucks more on a unit you know will perform when you need it. Most cities have at least one fire safety company that sells and services fire extinguishers; personally, I’d rather spend a little more money with a local company and build a relationship that’ll pay benefits down the road.

You’re also going to need to know how to use a fire extinguisher. It’s not second nature at all, and when it comes time to use one, it’s not the time to be RTFMing. At a minimum you’ll want to watch some good training videos so you at least have the basics. But nothing beats hands-on training. Your local fire service company can help there, although they may charge for live-fire training. You might also try contacting your local fire station; the firefighters will likely be more than happy to help you get trained.


When all else fails, you need to be able to get out of danger. Again, this takes forethought. You need to consider escape routes as part of your safety audit. Make sure you identify at least two routes of retreat, in case one route is blocked by fire. And don’t forget to practice your plan – in a crisis we tend not to rise to the occasion but instead perform at the highest level of proficiency to which we’ve trained.

Whatever your game is, if you’re reading Hackaday, chances are pretty good that you do something more dangerous than the average Joe on a pretty regular basis. Wouldn’t it make sense to be a little smarter and a little better prepared than the average Joe, too?

Source link