Can you weld? I made the first 100 metres of my line out of 4" I-beam, ripped with a skill-saw and cut-off disk then welded on a flat bar on top of the resulting T. Could have increased the size of the flatbar and also could have ground a curve on the outside to make a better looking rail. I've also made lighter 10LB by just using flatbars but that requires a lot more welding.
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flic.kr]
Cheers from Under
Chris
in New Zealand