I'm pondering the question of whether I need a bigger welder. I currently have a Cytringan "Bantam" 180 A oil-cooled machine. It's almost identical to the more common Pickhill and Oxford "Bantam" sets. Perhaps users of these British oil-cooled machines could give me their thoughts here?
I have build a lot of stuff using 3 mm thick mild steel. My current welder copes with this comfortably. A while ago I switched to using 6011 electrodes instead of 6013 because I wasn't happy with the strength of the welds I was getting and was also having some problems with slag inclusions in awkward welds. 6011 electrodes are giving me much stronger welds, but need a higher open circuit voltage to strike an arc. So now I am using the 80 V terminal on my welder instead of the 50 V terminal.
This is still fine for welding 3 mm and 4 mm steel with 3.25 mm electrodes as it gives an output up to 120 A. But I have bigger projects in mind. I want to make a chassis for my phase convertor and a frame for a hydraulic press. These will require at least 6 mm steel. I want the welds to have a similar strength and stiffness to the parent metal. In other words I don't want to be using thicker steel for little gain. So I want to keep using the 6011 electrodes which I've been very pleased with. But I'm not sure that I'm going to get adequate penetration in a single pass using 3.25 mm electrodes on my current machine. I'm not sure if I should move up to 4.0 mm or 4.7 mm electrodes. And I don't want to be struggling with a task of which my welder is barely capable.
So does anyone have strong feelings about whether or not my welder is up to the job? If I was to get another machine I would almost certainly go for another Oxford-style oil-cooled machine. Probably a 300 A @ 50 V /200 A @ 80 V machine. A fine current adjustment would be nice too. I believe there's a machine in the Oxford range which roughly meets this specification. I also like the really old cube-shaped English Electric machines, but I'm not sure that they have an 80 V output. Anyone in the Midlands got an idle machine they want to sell?