Mig welders. Jan 16, 2019 12:13:56 GMT
Post by grumpynorthener on Jan 16, 2019 12:13:56 GMT
My advice on gas - I use BOC Argoshield light and always have good results with it - On my old Clarke 185E I like to use 0.6 wire it just works really well as I seldom go more than 3mm steel thickness. Mask wise I have a Lincoln (Viking)which is almost half your welder budget but I would say that £90-100 on the helmet will pay for itself. Prep is the key. Welding time is pretty much 90% prep and 10% welding.
20mm plate butt with a 185 ? - 30-40 Amps / mm so about 5mm thick as a single pass - prep with a 45 angle to a 4mm root and a 1.5mm gap first pass will put the heat in and form the pass to go with up to 10 further passes which will give the heat to provide the penetration as the passes build - depending on the weld length it may well give the welder a pounding on the duty cycle but if you needed to weld something that big together there are ways. A 10mm pass through a double 45 one side 10mm deep 3 passes and then 3 passes on the other. 90 T - root and two sets of caps 6 passes.
Quite right with the prep & gas advice but welding 20mm plate with a under rated MIG - it's bit like a twin axle car trailer loaded with a Range Rover and towing it up hill with a Reliant Robin - it might do the job somehow - however the vast majority of us just want to get the job done and in the 20mm plate example would just go and hire the right piece of kit to weld it with or take it to a local fabricator and get the job done efficiently.