Too many variables for a simple answer.
Are the concrete walls below grade?
Was there any damp proofing of the concrete exterior?
Any moisture producing appliances like a furnace, washer/dryer or a shower?
Adequate ventilation in the basement?
I'm a total rookie, with a Craftsman welder. Those look like my attempts at welding.
I don't mind grinding some uglies on my stuff, but I don't do life/safety equipment.
I'm working a 'quick and dirty' version for my shop. No attempts will be made to match your fit and finish.
I would like to ask how thick is the material you used for the legs?
Thanks