Paint welded steel fabrications

Guided fabrication coating

Guide to painting welded steel fabrications

Welded steel fabrications need careful preparation around weld seams, heat marks, corners and cut edges. Cleaning, mechanical keying, epoxy primer and a durable PU finish help the coating protect both the visible faces and the vulnerable fabrication details.

What do you need to paint welded steel fabrications?

Cleaning and degreasing

Mipa silicone remover in liquid or spray format removes wax, grease and silicone so sanding, primer and topcoat work starts from a clean metal surface.

Fine surface keying

MP Fine sanding pad green helps matt edges, folds and profile details before recoating without cutting too aggressively into existing paint.

Epoxy primer system

Mipa EP 100-20 with Mipa EP 950-25 hardener and Mipa EP Thinner creates a zinc phosphate epoxy primer layer for steel, aluminium, zinc-coated metal and other demanding substrates.

Heavy-duty semi-gloss PU finish

Mipa PU 240-50 with Mipa PU 912-25 hardener and Mipa 2K Thinner Normal V25 gives a durable 2K polyurethane acrylic finish for highly stressed steel constructions and exterior metalwork.

2K spray finish for local areas

Mipa Mix PU 240 2K Paint Spray 48+ 400 ml is useful for small sections, welded edges and local repair areas where a 2K aerosol is more practical than a full liquid application.

How to paint welded steel fabrications

1
Clean fabrication residues

Remove oil, dust, marking fluid and handling contamination from the welded part before sanding.
2
Dress welds and edges

Smooth sharp burrs, weld spatter and loose scale so primer can cover the shape consistently.
3
Key the surface

Abrade flat faces, inside corners and weld-adjacent areas, then clean again before primer.
4
Prime vulnerable zones

Apply the EP primer system to bare steel, weld seams, cut edges and repaired corrosion points.
5
Finish with PU coating

Apply the PU 240 semi-gloss coating to the prepared fabrication and use the 2K spray for smaller brackets or hard-to-reach weld details.

Which fabrication coating products should you choose?

For main steel surfaces

Choose the PU 240 liquid coating for fabricated frames, brackets, guards and panels that need a durable industrial semi-gloss finish.

For welds and cut edges

Choose the EP primer system where bare steel, heat-affected areas and ground welds need a protective base.

For small fabricated parts

Choose the PU 240 2K spray when a small part or local repair needs the same type of 2K finish without a larger coating setup.

Technical details

Mipa PU 240-50 is a 2K polyurethane acrylic coating for highly stressed machines and constructions.
Mipa EP 100-20 with EP 950-25 hardener forms a zinc phosphate epoxy primer for prepared steel and other demanding substrates.
Weld seams, cut edges and holes have less coating coverage naturally, so these areas need deliberate primer and topcoat attention.
Fine sanding pads help key profiles without creating deep scratches that remain visible under semi-gloss coating.
A clean surface after fabrication is critical because oil, marker residue and handling contamination can weaken adhesion.

Practical suggestion

Hang or support small fabrications so all sides can be coated without touching fresh paint on lower edges or hidden faces.