Yeah, I was thinking of that post, but I forgot where it was. I haven’t bookmarked all the ones I want for reference, yet.
Chlorine gas. Don’t even think about it.
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sort of, the real concern is that it immediately takes on water from the air to form HCl and HClO (which pretty quickly converts to HCl and O2).
Nice work! That looks great I think 
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But in our context it’s more damaging to the machine than to people. It takes a fair amount to hurt you and in concentrated form - the stuff produced by a laser is headed out the exhaust where it will be rapidly dispersed into a cloud of good air. That’s not to say you want to be sticking your head in your laser and doing deep breathing exercises 
The real issue is the damage it does to electronics. It’s highly corrosive. Really highly corrosive. In mist form it gets everywhere and will eat a laser in a matter of days. It looks like it’s been in the ocean for decades or like it rotted out. Just amazing when you see what it will do.
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yes because in our context it immediately forms HCl
Actually remember your stomach is full of very high molar HCl. Every time you belch or have heartburn/reflux that is the HCl coming up your esophagus (and you typically breathe a reasonable amount in - it’s OK you are designed for this, we all do it every night while asleep). We will often see pH around 1.5 in gastric contents (takes a lot of burning to reduce that Shake Shack burger!).
We (mammals) actually count on the super low pH to keep up safe from bacteria, as without it - omeprazole I am looking at you - you aspirate bacteria laden oral contents at night; this is why long term use of proton-pump inhibitors in the elderly increase the risk of aspiration pneumonia. You’d have to generate a lot of HCl gas to be a problem for you nearby, not saying HCl is good for you and Cl gas is way worse as it forms all sorts of nasty compounds in you including HCl inside cells, but unless you are massively cutting chlorine laden stuff with your head in the output vent, much more likely you would destroy your device first (which would harm badly you by GWS - GlowForge Withdrawal Syndrome)…
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I should add, your eyes on the other hand do not like acidic fumes… As anyone near a pool knows, or sometimes you note some eye burning after a particularly large belch… Far more dangerous at even lower levels to your eyes, and that damage can be permanent - so always have full eye protection when working with acids.
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Great work. Thanks for such good step by step
Is it possible to use a heat gun in place of an oven to warm the acrylic? I assume that would be a lot more difficult but could bypass the issue of doing this in your home kitchen with a chance of fire/fumes.
I didn’t try it since the comments about using a heat gun talked about how hard it was to do.
One off bowls for proof of concept doesn’t concern me too much. I wouldn’t do a production run.
I have an old oven at my farm that would work perfect for this. It’s small and I don’t use it any more. If I decide to make more, I have that.
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Don’t think so. I couldn’t get the whole piece to reach & hold the temperature needed. I didn’t want to use the kitchen oven so I went with my gas grill. Worked fine - just watch your temps.
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It could possibly work to make a more “abstract” bowl? (Haven’t tried but imagine would cause more of an uneven “slump”)
heat guns can work, but they take a lot of time. The ideal if you want to use a heat gun is that your molding surface is metal, and you aim the heat gun at the metal instead of the acrylic.
If you have enough spare metal laying around to build your own enclosure around the acrylic and whatever you slump against, you can build a pseudo-oven wherever you want.
Or if you go to a local appliance store, they quite likely do installations and offer free removal of the old appliance. Then probably store those old appliances in the back of the building until they have enough to load a truck for a run to the landfill. Ask for an old oven, and you probably get it for free.
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which is why onions hurt so much!
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Do you also use the gas grill for food? If so, why is using the grill for heating acryclic more favorable than the oven?
Because it’s outside, isn’t my wife’s oven and is part of the “man domain”. 
I have a dedicated sheet pan that I put my forming bowls on so if anything bad happens it happens on my sheet pan.
I usually turn the fire off after heating it up too. That takes care of the fire risk (arguably minimal) as well.
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For years I’ve had contacts and was the designated onion cutter because I was gifted with itty bitty shields against the assault. Now that I got lasik and don’t need them I’m still the onion cutter and I see what all the fuss was about
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yeah, although that’s sulfuric rather than hydrochloric… Which is even worse.
Supposedly it helps to put the onion in the freezer for 10 minutes before you cut it. Which mostly makes sense if the problem is the juices from the onion going airborne.