As a rule of thumb, 3% weight of weld is added to the net weight of heavy construction equipment frames. If his goal is to stay under 1500kg, he will burn 45kg or three rolls of welding wire.
If you turnover 1000 tons of steel in the period you use 30 one ton pallets of welding wire, you get a pretty accurate rule of thumb for cost price calculations
It might be a little less for thinner steel, because if you fillet weld, the amount of required welding material quadruples if you double the welds cross section height. But on the other hand, a blunt corner weld on thin steel is 90 degree and therefor takes double the amount of weld than when a weld with the same cross section is welded on 45 degree beveled plate edges, as is common on heavy plates... so yes, i'd say youre not getting by with just two rolls
Thanks for the link. I wouldn't want you to side track this thread either. I just thought that some production "behind the scene" pics in the welding section would interest those following this build. Those "high reach" demolition booms must take tremdous forces while needing to remain as light as possible for the carrier.