Fire Extinguisher

Just preparing my work area for when the GF arrives… I have named it the "Ghost"
What are your recommendations with regard to the possibility of fire !!! Fire Blanket, extinguisher (what type) etc.



Spray bottle of water — :ballot_box_with_check:
Damp rag — :ballot_box_with_check:
Halotron extinguisher — :ballot_box_with_check:

Peace of Mind – Priceless


I have a dual method smoke detector, carbon monoxide detector, as well as a 5 lb Halon fire extinguisher. Halon is expensive, however this is NO residue or powder to clean up. Make sure you educate yourself a bit about it, and how it functions as a fire supressant/extinguisher though. There is a potential suffocation hazard due to how it displaces oxygen. Although if you have a fire, and get it put out, I’m sure you’d open windows to air the place out. Just wanted to have full disclosure.

Regular powder fire extinguishers are caustic, and are a pain to clean and will corrode aluminum & stainless from what I understand.

Here’s a link to the fire extinguisher that I have.
Amerex B386T, 5lb Halotron I Class B C Fire Extinguisher


Thanks for the feedback

I have not found what I am looking for but a CO2 extinguisher would seem to be best unless the cold could break something.

Good to know about powder though straight bicarbonate would seem more benign and not corrode metals, particularly stainless.

Halon is preferred for electronics and computers. But realistically if the GF is burning enough that the flames can’t be extinguished with a cloth or water spritz and needs an extinguisher, you’re going to be replacing so much wiring and boards that cleaning the residue from a standard electrical fire rated extinguisher is gonna be the least of your worries.


When cutting cardboard or paper I try and remember to have a damp rag at the ready. My first day or so I used a damp rag on some cardboard before I knew what I was doing. The second time there was fire I had a piece of parchment paper fly into the laser beam’s path and catch fire. It was swirling around and I just opened the lid and extinguished the fire with my hand. Not much pent-up thermal energy in parchment paper. I also have a 5lb halon fire extinguisher just around the corner from the glowforge, but as jamesdhatch pointed out, if it gets to that point your unit is toast. In my case, however, just around the corner is a kitchen so two birds, one fire extinguisher.


I’m a former fire protection contractor and GF owner. (It’s a very small Venn diagram!)

You’re not going to suffocate from a 5lb. Halotron extinguisher. The issue you’re referring to was for computer room systems that dump 500lbs. of Halon into a room at once. But, you should vent it after use.

Halotron extinguishers are pricey to buy (~$150) and expensive to recharge, although you can use the extinguisher multiple times (unlike an ABC, which needs a recharge after any use; valve won’t reseat over powder). The 2.5lb size is more than adequate for the Glowforge.

ABC powder is highly corrosive. BC powder is inert, but won’t do the job; it’s made for grease fires, and while it smothers flame it doesn’t do much else. Don’t use either for the GF, as they’ll also make a powdery mess in the machine.

Might reach first, though, for the wet rag or spray bottle.


So I’ve read the comments and suggestions above, but don’t know much about extinguishers and want to be as safe as possible but also frugal (I’m on disability and no income at this time). Can someone tell me what are the necessary check boxes for an extinguisher to work but may be harder to clean etc? We have smoke and CO2 detector already in that space its seems just far enough away to not trigger from the light amount of smoke that sometimes you can smell but not see when you open the GF, now I just need an extinguisher. My wife and I also will always make sure its being monitored as this is in our family home and too important not to.

Best (and cheapest) habit you can get into is to not leave the jobs to run unattended. (Lots of rules about doing that, but it’s like cooking…you don’t turn the flame on high and go take a nap…you keep an eye on it. Like any other power tool.) You can press the white button while the job is running to pause the laser if you have to leave the room.

If something does get a little flamey, you open the lid for a fraction of a second just to break the magnetic seal, and it kills the laser. That kills the source of ignition, and you can spray the material in the bed with a little misting bottle of water to put out any flames. I keep one by the machine at all times.

If you keep an eye on it, you don’t need a large fancy fire extinguisher…you don’t want to let it get to the point of needing one. But if that happens, the machine is designed to self destruct before burning your house down, and there have unfortunately been cases of people who run jobs and leave to go do other things, and aren’t there to stop the spreading fire. The worst of these cases made a big mess, and ruined the machines, but the fires all burned themselves out in the machines and did not set fire to anything else.

So you can probably get by with a very small CO2 extinguisher that you keep near the machine. People have recommended the halotron extinguishers to keep from doing a lot of damage to the interior of the machine, but if you get to the point that you need to use one, it’s already damaged. I do have a halotron extinguisher, but I bought it before the machine arrived. You can probably just pick up a small CO2 model as extra insurance to have on hand.

A damp rag would also work, or a fire blanket cut to size, but I have one of those and it’s still in the package…too large and too stiff. The misting bottle is all I’ve ever used…once…when some foam got a little overdone.


Great ideas. Definitely going to do those (mister, fire blanket, small ext). I know anything like this could potentially one day have an issue, most of the time user had something to do with it - like cleaning it, or using wrong material, but I do want to be safe. Awesome to hear that they engineered it to contain the issue. We definitely stay with it while we run it — now we may be doing something else on the workdesk next to it, but its higher and so we can see the GF easily with a glance. One day I want to be able to let my oldest girl be able to run her own designs, and she’s mature enough to handle it but again want to make it as safe as possible before we allow that (also going to give her a couple more years probably)
This spammer was spamming the forums b/c he was unhappy with his GF that he claimed were all broken on arrival and the photos from others showed the fires and I saw evidence of what you describe with its design. The internals might all catch fire if you don’t stop it, but it looks like there was no or very little damage outside of the unit. (Note, I do not believe that guy if you know who I’m talking about - he was even trying to sell people lenses he made instead of from GF which is crazy dangerous). He just got me to thinking about how far our kitchen extengisher is and wasn’t even sure it would be the same kind for a laser.

I appreciate the advice and am going to get that taken care of.
Do you know if I bought a fire blanket from Amazon (ships and sold by) that its legit - i know amazon sometimes has counterfeiters and wanted to see if they are where you got yours.

I think I picked mine up at Amazon…but I don’t like it much…it’s too large and pretty stiff. So that might not be the right place to go.

I know someone who works at a fire place for setting up fire safety stuff in business I’ll ask them (forgot about him till my wife just reminded me).
Thanks again.


Make sure transfer tape paper is SMOOTH and NO air pocket bubbles on either side

After I attach the paper I use an old credit card to smooth it down.

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There are a few woods that if a coal gets started it will stay alive until it has eaten the entire piece piece of wood, and never break into a flame. After many years trying to get a fireplace started I learned that unless there is a place that has two sides facing each other keeping each other hot, the fire rarely manages much even when you want it to, (cardboard, from shipping boxes has a lot of such places so needs extra intense watching)

Even acrylic has to be hot enough that the gasses from evaporating plastic are enough to cause the flame for more gasses. For this most GF fires I have seen the photos from are from acrylic fires. That is why for all the Glowforges out there fires are pretty rare, but 1% probability is still 100% if it is you that allows the issue.

All that said if there is a candle flame that can sustain itself when the the cut is not there it can grow very quickly, and even a coal sustained will eat up all your work, even if it does not eat your Glowforge.

So a big question becomes what you put a small fire out with that will not destroy your Glowforge just from using it? Many kitchen fire extinguishers contain chemicals as bad or worse than PVC and if there was a fire that did not yet explode the lid I personally would not use them as any possible salvage would likely be moot at that point,

For this reason an empty, washed, spray cleaner bottle filled with water is likely all you might ever need, as it will quickly lower the temp of the material enough to stop the fire and not even prevent you from doing more cutting. Zebrawood and some wood sold as mahogany are prone enough to this that I have even cut them while wet.


Apart from the smoke detectors, I always have a damp rag ready to put out any small fires or things that ignite. But for those that get out of hand, I took recommendations from this maker John Kuiphoff. He uses the Fire Blanket and EZ Fire Spray on Amazon.

Phone preprogrammed with 911…

My new phone (Pixel 4 5G) is supposed to call 911 automatically if I get hurt. Not sure what magic Google is using to decide I’m incapacitated. :slightly_smiling_face:

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Well the Apple Watch can do that for falling but it’s accelerometer is set to sense sudden jarring movement. I’ve set it off about 10x in 2 years. Ripping down tree limbs, snapping limbs over legs, a few actual falls tripping over stuff at jobs, some impact exercise. It taps you with a 10? sec timer before it calls for emergency services.


We have a Ring camera watching the machine at all times - just above the lid so it will trigger on smoke or flames or flashes. We have a 10 lbs CO2 extinguisher (bought from Webstaurant) - very expensive but worth it. Smoke detectors (one low and one high), CO2 detector, fire blanket, spray bottle with water (for anything on the bed). We vent outside. We rarely cut acrylic, rarely cut wood and if so we do it in small jobs and sections. And we’ve learned to clean the machine regularaly. In particular the back exhaust honeycomb.

The biggest precaution though is of course to watch the machine. I don’t stand over it but I sit about 8’ away from it and use a Ring to watch it while it works and I watch the Ring.