Walrus Double-Standard Frankentandem

It's a 9 litre oxygen tank, so it should last a few hours, but just little cans of propylene/propane mix, so a bit hotter than just propane, but probably don't last long (the website reckoned 2 hours with a number 7 nozzle). I still had some problems where there was a lot of thick headtube and reinforcing gussets, so have bought some bigger nozzles. Just waiting for some child free / non-dark outside time. Seems to be a rare thing nowadays.

I don't have a power file! Is there one you would recommend?

Nice, thanks for the info. Might just have to go tig!

As for power files, at work we use air tools, but i've used these B&D ones before and they are ok for the money and seem to keep running. http://www.google.co.uk/products/catalog?q=powerfile&um=1&ie=UTF-8&tbm=shop&cid=3807651808055832786&sa=X&ei=ei16T-jSO8i_0QWC1p3cCQ&ved=0CIEBEPICMAA