My coffee maker brews coffee into a “thermal carafe,” which is hoity-toity-speak for “big thermos bottle.” I was cleaning it this morning in my usual way. I filled the carafe with hot soapy water, then (gently!) scrubbed the inside with a long-handled dish scrubbing brush.
It exploded.
I was just lifting the scrub brush to make another swipe, and POP! My ears were suddenly ringing (heck, they’re still ringing) and my carafe was reduced to a pile of shards. I suppose it’s more precise to say the carafe imploded, but that doesn’t really convey the shock of the experience. Fortunately, all the glass appears to have been contained by the plastic shell.
I’ve got two questions:
[ol]
[li]How common is this? (I’ve *never *heard of this happening before. A Google search on “exploding thermos” mostly returns James Bond links.)[/li]
[li]What did I do wrong?[/li][/ol]
the glass in those carafes is usually pretty thin and the whole works is essentially suspended by the neck/top of the unit, and surrounded by a vacuum. YOu probably just hit the bottom a little to hard or possibly put a little torque across the lip or neck of the glass when you removed the brush.
The neck is supporting the entire weight of the glass sleeve so it really doesnt take much down pressure or sideways pressure to cause breakage at that point.
The breakage in my carafe has revealed the internal construction - there are padded supports for the vacuum bottle around the sides, as well as a screw-in plug in the bottom. That doesn’t mean the neck wasn’t a high-stress area, but it wasn’t the sole support.
Nevertheless, I appriciate that the vacuum bottle may be a delicate thing. Maybe I was too rough. What confounds me is that washing the bottle this way is something I’ve done weekly for a couple of years - if this treatment was too rough, I’m amazed it lasted as long as it did.
Maybe you just had a bad one. Hot and cold stresses finally persuaded a microscopic crack to start expanding like mad.
On the other hand, is there any chance that your scrub brush had any kind of abrasive on it? Sand grains, carbide fragments, etc? I hear that if you touch a sharp carbide tool to highly stressed glass, the small amount of surface damage will instantly grow into large cracks. In theory, any substance that is hard enough to scratch glass could trigger the explosion.
Well, it’s full of ground glass now! Does that count?
That’s interesting about scratching glass. This was a pretty ordinary dime-store brush with stiff plastic bristles. I don’t recall using abrasive cleansers with it before, but things get mixed up in a kitchen - who knows? I have seen plastic scrubber items scratch and abrade metal pots and pans before - maybe this was it.
I take it from the dearth of “Oh, that’s happened to me three times” type responses that this is a pretty rare event. I sure hope so, anyway. I much prefer the caffeine-style wake-up I was expecting, rather than the gunshot style one that I got.
Lagged2Death, you probably were scratching the inside of the carafe every time you washed it. This was just the day when it had weakened enough to fail.
I think if (s)he (<-how does one find out these things on forums?) would have said vacuum bottle (s)he would have gotten crickets and blank stares. I think it’s safe to say the trademark is sufficiantly diliuted.
