3 litre conical has cracked!

[Hop Bomb]

I made a starter last night. Mixed my DME & water then added it to the flask. I then put my flask on my little camping stove (gas flame) & walked out of the room.
A minute later I heard a crack & upon inspection saw a big smile like crack running right across the bottom. What did I do wrong?

[Shane Phelan]

That sucks dude, they are made of thick borosilicate glass and should be well able to deal with a gas stove.

I have contacted the manufacturer directly about it and I will get back to you here with their reply.

[Hop Bomb]

That sucks dude, they are made of thick borosilicate glass and should be well able to deal with a gas stove.

I have contacted the manufacturer directly about it and I will get back to you here with their reply.

Thats what I figured. It was its maiden voyage too    Thanks a million for mailing them. No worries if nothing comes of it.

[Shane Phelan]

Oh it was the maiden voyage too! I'm going to go after them for a replacement in that case. You haven't dumped it have you?

[Hop Bomb]

Oh it was the maiden voyage too! I'm going to go after them for a replacement in that case. You haven't dumped it have you?

No I still have it. Do you want me to send it up to you or take pics? Appreciate the help.

[Shane Phelan]

Hold onto it for now. They have forwarded my query onto tech support in the UK which can take up to 3 days. If they want it back I'll just get you to post it to them directly.

[Hop Bomb]

Fair play. I wasnt expecting this at all. I was guessing it was something I did wrong.

[biertourist]

Borosilicate should NOT crack under heat like this... It's not a good sign that it DID crack...


Adam

[Shane Phelan]

Yeah it cant be anything else than a manufacturing defect.

I was talking to my auld lad over the weekend who has been boiling liquid in them for as long as he can remember in his lab and he has never seen one crack or break over a flame.

[DEMPSEY]

Is your auld lad the guy from Breaking Bad

[Shane Phelan]

Is your auld lad the guy from Breaking Bad

:

Just to update, I haven't waited for their support guys to get back to me, I have asked them to just replace it.

[Will_D]

On a domestic gas cooker a single concentrated flame jet CAN locally overheat the flask.

If you use a naked gas jet/bunsen burner then you need to diffuse the heat.

This is the old wire gauze square thing we used in school labs (just nowadays they won' have the asbestoss centre pad - coughs and weezes loudly )

How do I know this? Coz I cracked an expensive, ground glass jointed thick walled Erlenmyer on a gas cooker the day after I bought it!!

Never use thick walled borosilicate glass ware on naked gas jets!

[Shane Phelan]

Never use thick walled borosilicate glass ware on naked gas jets!

Is there are reference to this in a specification?  From searching so far I see a mixed bag as to what is acceptable and what is not...

[Will_D]

Shane,

I really think its down to laboratory practical experience.

Thick walled Erlemyers are used for vacuum filtration ONLY and as the conical section and flat bottom are not good under a vacuum they beef up the thickness!

Likewise a thin walled flat bottom flask should not be used under vacuum.

Localised overheating coupled with a "minor" flaw and poor fluid distribution on the wet side will cause a problem.

Remember you can boil water in a paper container but thick cardboard will probably burn through!!

However I would still class this as faulty!

(Purpose of this post is just to give the heads up to others who may not be lab. experienced)

[Shane Phelan]

Yeah that was the one question my auld lad asked, was the outside of the flask wet when he started heating it. Personally I have heated my 3L conical with the outside wet but that was on an electrical cooker. Overall I have treated it like shite without any problems, such as heating when wet, dunking into ice water when boiling hot etc...

Will, you have one of the 3L flasks yourself so you can see how thick the glass is, IMO they are absolute tanks of things. The glass is very thick. I don't know whether Tom was using his flask with a vacuum or not, I would guess not as most of us are just boiling in the flasks at most...

If they don't replace it, I am pretty much going to suggest that they are putting people at risk by selling defective products to customers. If that flask had of ruptured over Toms arm while boiling that would have resulted in some serious burns which is fairly unacceptable to me.