OT Capacitors & Welding

Hello all,

I have a cheap 100 amp something MIG set. It's not a Miller Pulse Master
Turbo 900001+ but it is very useful for speedy, neat welds. I have possibly
the most annoying problem on Earth with it however. We have some circuit
brakers here and whenever I go to weld with the set one trips. I have done
lots of experimenting and found that it will only trip when the wire is not
in direct contact with the work piece when the current is turned on. It will
trip even when I pull the trigger with the gun a metre or so from the work
piece. It's indescribably, hand bittingly, wicky. Especially since all the
lights in the garage are on that braker as well so I then have to mavourver
out the garage in the dark (You haven't seen our garage!). Occasionally the
braker for the a hole block of brakers will trip but it's almost always just
the one for the garage circuit.

My thinking:
Perhaps there is ground leakage? I investigated by wiring it up minus the
Earth. What else can trip them? Current surges. Would the surge current to
start an arc be higher than with a direct metal to metal connection? It
might be. This means I must clip the end of the wire after each run with the
welder before I can strike it again. It also means any muck on the surface
has me going in to turn the braker back on. So I'm at my end with this thing
now. It can take me an hour or more to make five minutes with of welding.

My latest plan:
I suspect it is the surge of current produced when it's not a direct metal -
metal contact. The metal to metal contact through the wire I am guessing
acts like a fuse and limits the current allowed through as it heats up and
melts back. It's common for my finger to slip a little, the arc to brake and
restart and for it to go off. But then why would it also trip with no
current flowing and the gun far away from the work? Something to do with the
inverter? My idea is to buy some of those Boy Racer car sterio capacitors
from ebay, the Farad + jobs. They're 24v each so I'll buy two and put them
together for 48v. They are rated at a 10,000amp surge individually. The plan
is to wire these in just after the mains voltage is stepped down to less
than 48v. Why? In an attempt to buffer the surge of current so the current
is not drawn straight through the brakers, but instead from the charge
slowly built up on the caps.

I'd really appreciate the opinion of some of the electrical geniuses on here
because I can't afford the hundreds of pounds they want for a high amperage
circuit braker and I really don't want to have to pay to have a whole new
circuit put in on a slow burn fuse which'd proberly be more than the welder
cost.

Sorry this is a bit off topic, thanks again,

John H.