You could use a piece of wool instead of a damp cloth. Wool is naturally fire resistant, so you don’t need to keep it damp.
I was planning on having a little spray bottle on hand to use on tiny flare ups before they become big flare ups!
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So I think at this point we can reccomend against big bad wolf impressions and huffing and puffing for peoples own safety too.
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Our library maker space has fire extinguishers. But it also has a spray bottle (like a windex bottle) next to the machine filled with water. Their space has been used 8 hours a day solid for the past 2-3 years, and they’ve never had to use the fire extinguishers. I’ve used the spray bottle once, when experimenting with paper.
I would recommend having a fire extinguisher for worst case scenarios. But most of the materials you cut will not light a fire under normal circumstances. And most “abnormal circumstance” fires can be put out with a spray bottle or wet rag.
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As promised, here is a deliberately started laser fire. I cannot imagine any fire starting faster than this, as cardboard LOVES to burn. I suppose if you put some oil soaked rags in there you might do better.
Quite a few things went “wrong” to make this fire. The cardboard was cut outline first, so that it popped up out of the focal plane. The speed was too low (or power too high) for cutting the cardboard in the first place. And multiple passes very near to one another happened.
With the start of the video, I show the cardboard being cut at an appropriate power and speed, in focal plane, and with only a single line. No problems at all.
The fire only happens when I am cutting cardboard which has popped off the bed, and I do cuts which double back close to themselves. I am also running at a lower speed during this point to ensure that I get a fire.
As you can see, just being there and watching means you can stop the fire pretty easily (granted, cardboard being easiest to start also means it is easiest to stop). There are obvious embers building up prior to ignition, and when the fire finally does start, it takes a while to really get a blaze going.
Were I not in the room or just not paying attention, within a minute the whole sheet of cardboard would be alight, and quite likely some embers would be scattered around my room by the force of the fire and the air assist (not a problem for people with an actual enclosure).
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Thanks for the video! That’s a really great demonstration.
I recently used cardboard scraps to start up my fireplace, and it was very enjoyable to watch!
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Thanks! I see also that you’re talking about corrugated, so you have a sheltered space for the fire to grow. (Makes me think of the building in my town that burned down right across from the fire dept – it was about 150 years old and had been renovated/rebuilt so many times that the walls were full of dead spaces filled with trash and scrap wood – went up in just a few minutes.)
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I forgot to mention that type of material was pretty key as well. Spot on for why I selected corrugated. Likely with a pizza box I would never have progressed beyond embers.
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Thanks for the demo!
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Be safe, watch your cuts while they’re going on. It’s hard for me to not do this anyways. CNC machines operating mesmerize me.
I also want to know why something messed up if there’s an error, so seeing it live would be nice. I try to install video recorders on my devices so I can watch if I have to leave the room and also record what’s going on.
I wonder if the camera on the glowforge will allow this type of functionality. It would be a shame if not.
Would even be cool to see footage from the flying head cam as it burned stuff away
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I’m going to do what Dan recommends and hold off until I see the manual.
I got a laser cutter 5 months ago and got a halotron extinguisher after tons of research on laser cutting forums and Facebook pages. I got mine on eBay for a fair price. Its more expensive then normal ones but much better for the electronics
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It’s not nearly as bad as Halon, but my understanding is that it’s still ozone-depleting and is scheduled to be phased out fairly soon under the Montreal Protocol.
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I like the backing soda and spray bottle ideas. Both of those can just be set next to the laser cutter and forgotten until needed. I bet a wet rag would work better, but knowing myself I will have neglected to get one ready the one time I need it.
If all of those fail, I’ll reach for one of these…
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The misnomer of Halotron being phased out comes from Montreal Protocol declaring new HCFC’s being phased out, depending on the industry you’re in. Halotron uses HCFC-123 as its main agent. Montreal Protocol doesn’t affect existing stockpiles of HCFC, nor does it affect recycling existing stockpiles.
Although new production of HCFC-123 used in fire extinguishers is ceasing, Halotron is continuing by recycling existing HCFC-123 stockpiles from non-fire protection industries, where there’s still high volume. So much volume, that they apparently feel they’ll have ample stock for many many years. And if that wasn’t enough: New HCFCs can be manufactured for purposes other than fire protection in the US after 2015.
So generally stated, they’re not going away – but it’s also not as ozone depleting as other HCFCs clean agents on the market.
Source: this document.
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Yes, I hope the manual will address what we should do under the flame/ on fire circumstance 
. Also, I wonder if GF laser machine has a special strategy or standard operating procedure which let users be able to shut down the machine, so the users could use proper distinguisher on the working bed or the flame area. In other words, I am thinking that we probably shouldn’t put off the ‘flame or fire’ while the laser machine is still working. Does this point make sense? 
Any ideas?
Opening the lid should instantly turn off the laser, unless I misunderstand what “safety interlocks” do.
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Hi Dan
After lots of conversation right in this topic, do you have any exact recommendation as an official advice to the best choice of fire extinguisher:fire_engine: for Glowforge? (As the same as the best choice of Certified Laser Safety Glasses?)
The post you replied to was Dan saying he won’t say anything on the forums about what we should do. But that the manual will have safety information.
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Correct, it will disengage the laser immediately. [quote=“jacobturner, post:38, topic:3208”]
the manual will have safety information.
[/quote]
Correct as well! 
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What we need is a sonic fire extinguisher: https://www.youtube.com/watch?v=hkUv5gCA-1w.
Glowforge MK2 could have one built in, triggered by the camera and some clever software.
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