Like I said my understanding came from a chat with an electrician. He was in a hardware store the same time I was buying an extension cord for my 15amp welder that I use at home.
From a bit of google research this morning it seems in Australia the wiring is the same size for 10amp and 15amp but the main difference is that a 15amp outlet is a dedicated outlet. In that a 10amp fuse often has multiple power outlets running to it. The 15amp runs on the same wiring but only allows the one unit to run from it. Hence a 15amp dedicated outlet stops you from running multiple appliances on the same line.
Only if you start changing the value of the circuit breakers are you gambling with your safety.
This is basically an issue we are up against often in the welding industry. You are welding away and someone decides to use a 9 inch grinder some where in the same circuit as you and bang the circuit breaker cuts the power. The Grinder must be plugged in to a different circuit or else not used at the same time as the welder. This can also happen with multiple high current 10amp appliances.
I use the 15amp welder at home on 10amp outlets (either change the plug or it is simple to grind down the earth pin to suit the smaller outlet plug) I don't remember overloading the 10amp breaker yet but I have not done overly hot welding at home. As long as you don't go mucking around changing circuit breakers they will tell you if you are overloading the circuit. One thing to remember is that an extension cord increases resistance so the shorter the better.
Off course a dedicated 15amp outlet is the way to go especially in the case of firing a kiln as you don't want a circuit getting cut as you are firing.
I forgot about this last time the electrician was here I will be sure to get a 15amp dedicated outlet next time we get him in.
This is the best understanding I found in my extensive
google search!
http://www.offroadfabnet.com/forums/sho ... hp?p=75652 It's too bad your in such a hurry cause the stories I could tell you, Bushels and baskets of stories, hole crates full of stories. But if you can spare a moment I will tell you one story.
I was not looking at where you where when I mentioned it. It is pretty dam heavy and would be at least more than the cost of the wheel 
this is your safety cable, how's yer safety 
