Something to be aware of

[PyroChixRock]

This morning a conversation made me realize that a lot of us might not be aware of a danger we all deal with on the regular.

I'm not sure if there's a proper term for it, but have you ever felt the tube you are blowing into shoot back pressure at you? It doesn't happen often, but it can be very dangerous. Snodgrass had a lung collapse from it, in fact. (Note, he didn't know his lung had collapsed right away.)

The way I deal with it is keeping my tongue near the end of the tube I'm blowing into in case it happens, so I can plug it very quickly and not allow it to shoot into my lungs. Also, just being aware of it so I don't breath in, which is a natural physical reaction.

I've noticed it happens from condensation building up in the tube, heating up and creating pressure, but I think it can happen without condensation, too.

If you've had this happen to you, tell us about your experience and what you think caused it, and if you have any tips on how you deal with preventing it from going into your lungs.

BTW, I've personally never had this happen, or heard of it happening, when using a blow hose. However, I think everyone should learn how to blow without the use of a hose because it will allow you to be a more versatile blower and rely on less tools. This danger is minimal, and not a reason to avoid learning to blow without a hose IMHO.

Oh yeah and...arr!!! :pirate:

[pepep]

Thank you! i believe this may happen when condensation creeps down the tube then hits a super hot section and flashes into steam. Steam van have a volume 1600 times greater than that drop of condensation. This push of heated gas is no fun.

[James Sowell]

there is a pop that happens when your flame is a bit reducing gas gets pushed up inside the blowtube then there is a flame front up inside your tube. you blow out of tube and see fire come out. it feels a little different then the moisture drop falling down tube . was blowing out something today and had both happen one right after another. the flame front you notice right as your blowing out you feel it sort of give gentle resistance like your pushing a boba ball out of a straw or something . the moisture in tube has a harder feel that is more random deff pushes back more against your blowing almost to point you can feel flow reverse right as it happens

[LooseSeal Baller]

it happens to me alot... Anytime i'm doing ring-seals or other seals where the flame actually shoots up inside the hollow work. I always thought it was un burnt propane or oxygen.
I've never really given it much thought, but have noticed it trying to shoot flames down my throat. Usually i wait an extra second, or blow air at the tube from far away, (by that i mean just blowing air at the blowtube hole either just like i'm whistling or with a sofietta, or puffing tool).

not sure what causes it but my blowtubes usually have lots of condensation. shoving a cork or ear-plug in the blow-tube end should help to prevent it from happening, it just depends on what you're making, sometimes you can't plug the blow-tube...idk

[istandalone24/7]

i've never felt that "blow back" but i have heard the blowtubes "hooting" at me from time to time. it's actually pretty funny sounding and always makes me chuckle.

[gemini]

This used to happen to me all the time when I used to melt glass a decade ago. Always scared the crap out of me but I got used to expecting it and I just thought it was a normal thing when working hollow forms. I was on a National at the time. Don't know if that makes any difference. Definitely felt like unburnt gasses in the tube though, not condensation. A flame would shoot out one of the holes (bowl hole or carb, or whatever) when I blew hard enough cause I didn't want that shit in my mouth.

[Greymatter Glass]

The one thing I can see that we'd be making that could cause these kinds of problems is nitrogen dioxide, NO2 (not nitrous oxide, laughing gas, N2O). Nitrogen Dioxide is a combustion product and pretty serious. I'd think you'd need a pretty big space to react enough NO2 compounds to present a serious danger. The normal complication from NO2 is edema, not collapsed lungs, but I'd imagine they could feel similar, not really sure - best to avoid those things entirely!

http://en.wikipedia.org/wiki/Nitrogen_dioxide

[fUmEsNiFfEr]

My teacher warned me of this when I was a wee sprout and told me about Snoddy.

I always thought it was just unburned gasses. I was told me to put my tongue up like when I'm smoking a joint.

Puffing at it like Barry said works too. I like to see how far the little flame will shoot :flamethro

[derekg0]

Ya this has definitely happened to me, and I usually see condensation in my blow tube. I've had it happen so much that it resonates and makes a whistling sound similar to blowing across the top of a beer bottle... definitely freaked me out the first time, i put down my work and just let it die on my bench because i didn't know what was going on.