its a 90 amp dosnt go any higher than that weld as low as 1mm thick steel up to 15mm but for strength i wouldnt be going over 10mm as its not big enough on amps
I can get a video of mine droning whilst welding and the hum
I don't think they are all that bad you could make an enclosure to stick over the tip of it when In use just make sure it has good ventilation and maybe a fan fitted