Can I use an Tea urn to ferment my cider in?

I Stumbled across a nice stainless steel Hot water Urn which holds 30L and has a handy tap on the front.
I was wondering wether it could be used to contain the cider throughout its fermentation process? I will NOT be using the heating element it is just as a container probably to hold the cider for 3 to 4 weeks untill i bottle it?
allso when should i bottle my cider as i bottled it way to soon before and it exploded when i opend the bottle and went everywere very comical but a sad sad waste of cider
Any feed back and answers will be Deeply apreciated
Tom

Do you have a picture?

It is stinless steel, which is good. I'm just wondering about air exposure and/or lack of a way for the CO2 to vent.

Do you have a hydrometer? Cider shouldn't be bottled any higher than 1.020, but it usually ferments to about .998 or so.

not at this moment in time. i am little worryed about the white oxadisation of the inside of the urn due to it has been used for some time now.
no i do not have a hydrometer is there anything elce i can use insted of this to see if it is ready to bottle?