Define the boundary
Measure the welding corner and mark where the frame must stand without blocking the garage door, electrical panel or ventilation path. Keep the frame light enough for one person to move.
The screen is intended to reduce arc exposure and organize the bay. It does not replace ventilation, fire separation or protective clothing.
Build square folding panels
Cut two matching frames, check diagonal measurements and tack the corners. Add a center brace only after the panel sits flat. Fit hinges with clearance for folding and verify the frame does not pinch the screen material.
Practice the joints on the same tube thickness. Forney's 140 FC-i is a 120V flux-core machine, so use its manual and circuit requirements.
Install the screen safely
Use a screen material intended for welding protection and follow its manufacturer's instructions. Keep the material away from the arc plume and hot spatter.
Test the frame folded and open before welding the final project. Store it where it cannot fall into the work area or block an exit.