Glass singing to me?!?!?

[oG Glocc Coma]

This is the first winter i've worked. While pulling points on 25x4 simax on my major/minor top fire i was going along just fine, pulled about 4 and went as normal. Start heating up end to pop so I can poor frit in. I start to blow to even wall thickness and let it cool for a few seconds when I start to hear a humming sound... at first i thought it was from my torch and quickly cut the gasses to the torch and it was still humming, I then inspected my regulators... not from them either! The sound stops.... i wait turn everything back on and hop on... I heat up end of tube and let cool for a second, it starts again! This time i noticed when setting down point it seemed to get quieted, i pick it back up and hold open end of point to my ear.... its humming!!!?!?!! Im sure something scientific is going on, now that im safety breakin hard i tried to Google but couldn't find?!?!

Help, please explain to me what is going on and put mt mind at ease!

[Yeef]

that's happened to me a lot. it has something to do with humidity, i think.

my thoughts are that the hot air heading out and the cooler air coming in sets up some kind of resonance, and has something to do with the density of the air, which is where the humidity comes in.

this might be 100% wrong. ed: but, it only happens to me regularly when my shop is humid.

the first time it happened i set the thing down and walked away while calling my glass prof to ask about it, it was a tiny-necked drop vessel i was working on and it was resonating so strongly i thought it might explode. hah..

[oG Glocc Coma]

Sooooo glad its not just me!

[Yeef]

yeah man, it freaked me right the fuck out. the thing was buzzing in my hand so hard it felt like a really light electric shock.

have you seen those fire organs that use glass tubes, and blast propane burners through them? i'm guessing there's something similar going on there..

[PyroChixRock]

It's condensation. And please PLEASE be careful. Read this.

[Yeef]

that's a good read. i learned to close my throat when i'm puffing, so if i get a backfire or steam my lips just blast open.. like those guys in the wind tunnel pics?

[BORO]

If I have a bubble on a open ended point , or handle it happens.... This is usually during the condensing of a fresh twist of line work. It can be a pulled point, or tube 9.5mm to 14mm , 2, 3 , 4 ,5mm thick bubble? 12" -16" inches of handle.)

If the side of the bubble closest to the handle is hot and glowing. The far end with no punty is not glowing , handle is not glowing much or at all. It hums 90% of the time.

As far as pressure pushing back in a blast. I have never had that happen , sounds super scary.....

[oG Glocc Coma]

Is that bit about blow hoses true and that it never happens? If so there's a reason for upgrade! I learned on points with no blow hose but i have had a few times that I think it would be useful and now this!

Ps any stats on how much psi to collapse a lung!?!? Just mind wondering !


Edit googled it, 15 psi!

[PyroChixRock]

I haven't heard of anyone saying it's happened to them with a blowhose.

[Credo]

I heard a pretty name for this phenomenon called Thermo Acoustics... Ive had this happens a few times and if I can manage it, I'll put my ear next to the end of my handle and just listen to what the glass has to say

[Aaron Ellis]

I've had steam blow back up but fortunatly only when im working it in the flame. It really ticks me off when I'm working a piece especially when its a larger more awkward piece and the steam shoots up the handle. You know the "have to set it down before you drop it kinda hot."
The thermo acoustics is nice to listen to almost meditative maybe. But the vibration always scared me feels like it's gonna explode.

You can make a long q-tip with a 2mm dowel and some cotton swab. Just run it through your blowtube when you see water building up.

[dplaza]

i make a ton of iso frit and it makes this noise all the time, mainly because i have a blank on punty fill with frit, then connect. the whole time i have to have the blowtube facing down so that the frit stays on the front half of the tube. im positive it has to do with moisture because when there is a visible amount of moisture it happens more frequently and more aggressively.

also have had the explosive air blast when blowing in, its freakin wierd glad i didn't pop my lung, i never thought about that. that i also believe is from unspent fuel building up in the tube, use a reducing flame on an open hole and your asking for it.

like say im heating up around a bowl hole on a spoon and using a reduction flame, all that unspent fuel that gets into the tube builds up, then i puff in to expand the hole and even the heat before the push, at that point it happens almost every time. usually the blast comes out the bowl hole but occasionally it shoots back out the blowtube.

its like an exhaust backfire, your revving the engine and its spitting a ton of fuel, then you snap the throttle closed and some of that unburnt fuel gets in the exhaust, then on the exit of the turn you open the throttle a little bit and a blast of hot lean air hits that fuel and boom!

ever notice how the water that condenses in the tube from unspent fuel if it gets on your lips burns and tastes like crap? pretty sure its full of hydrocarbon and carcinogenic.

also i just got a blowhose recently and although it makes some things way easier, or even possible, its super cumbersome after learning without it and i cant blow through it with even close to as much volume for popping holes but i also have the 1/4" swivel

[Loki Glass]

Thanks for the link Misha, I missed that other thread and have this happen occasionally. Glad I didn't collapse a lung that I know of. Something fairly ironic about this is I just got off facebook where a friend of mine (not a glassblower) is in the hospital for a collapsed lung... Scary stuff, but thanks for sharing!

I also notice the the most when I'm using frit and it's humid out. I live in a very humid area and am always dealing with leftover condensation when heating up cool glass. I've started leaving blowtubes on top of the kiln to keep them warm and avoid the issue when attaching the blowtube to the blank. More than the humming I was worried about the condensation dripping down, hitting the frit before it's all fully melted in and cracking the piece, which has happened on quite a few occasions. Along with getting frit stuck all over in the blowtube.

[derekg0]

Lol, first time this happened to me i was trying to do my first stick stack and I had just sealed the end of the inner and outer tubes, and it got so bad about 20 minutes into the melt down that I just stopped and gave up on it. I had never experienced it before and it was vibrating so hard that it scared the crap out of me. Anyways, now I am slightly less scared of it knowing what it is and what to be worried about.

[Super Phunk]

Wow only about the 100 thousandth million time this has been brought up..... The search function is your frIend

[oG Glocc Coma]

Wow only about the 100 thousandth million time this has been brought up..... The search function is your frIend

Little hard to search when I didn't know what was going on with it... Thanks for your input though, Im sure everyone will value you it til the end of time since its such an awesome and original answer!


I got all the info I needed an even a helpful link before you could even chime in, congrats!

Please Close thread Mish

[PyroChixRock]

Wow only about the 100 thousandth million time this has been brought up..... The search function is your frIend

Actually this hasn't come up a ton. Also, please read this thread.

[art]

I have had this happen to me about 3-4 months ago. I was blowing into a spoon to pop the carb and all of a sudden it felt like fire went down my throat. My lungs spasmed for a few seconds but I went to the doctor and they couldn't find any damage. It was pretty funny, I told the doctor and nurses I inhaled fire and all they could think of was that I had inhaled smoke or asbestos for some reason lol. Then the doctor told me of his neighbor back in the day who was a scientific glassblower who melted glass while on a unicycle. I would really like to see that haha.

[CaptainKeef]

I always thought I was doing something right when it starts humming... Seems like it happens to me when the wall thickness and heat base is really even when I come out of the flame. Never made the connection with humidity or realized it could be dangerous thanks for the info