Repair a rust spot and repaint the panel

Guided Shopping · rust spot repair

Guide to repairing a rust spot and repainting the panel

A rust spot must be cleaned back to a stable surface before any cosmetic paint work starts. Epoxy primer protection, suitable filler, primer preparation, basecoat and clearcoat help rebuild the panel in the correct order.

What do you need to repair a rust spot and repaint the panel?

Cleaning and degreasing

Mipa silicone remover in liquid format and Mipa silicone remover spray remove wax, grease and silicone before sanding or coating. Clean again after sanding so dust and fingerprints do not sit under the new finish.

Epoxy primer protection

Mipa EP Primer Surfacer with the matching EP hardener and EP thinner gives direct adhesion and corrosion protection on prepared steel, aluminium or zinc. It is the stronger primer method for bare or sensitive metal.

Rust repair support

Mipa P 50 glass fibre filler supports stronger filling on rougher damaged areas, while Miparox anti rust spray helps protect cleaned local metal before the repaint build continues.

Body filler shaping

Mipa P 99 Multi Star fills and finishes metal repair areas before primer. It is useful when one repaired panel needs a level surface rather than only a scuffed existing finish.

Basecoat colour layer

Mipa BC Ready Mixed Two Layer Basecoat creates the matched colour layer on the prepared panel, while Mipa BC Thinner VDG supports the spray viscosity required by the BC system.

Clearcoat protection

Mipa 2K HS Clearcoat CC 8, Mipa 2K HS Hardener HS 25 normal and Mipa 2K Thinner Normal V 25 form the gloss and protection layer after the basecoat has flashed.

Flat sanding support

The MP sanding block keeps hand pressure even across the repair area, panel edge and primer surface. A flat block helps avoid waves that become more visible after gloss clearcoat.

How to repair a rust spot and repaint the panel

  1. 1
    Remove rust and unstable coating

    Remove loose rust, failed paint and weak edges until only a stable repair surface remains. Do not paint over active rust or loose coating.

  2. 2
    Clean and assess the surface

    Remove wax, grease, dust and loose contamination from the rust spot. Check whether the existing coating is sound enough to sand, or whether deeper repair work is needed first.

  3. 3
    Shape the repair area

    Apply the correct filler only where the panel needs shape correction, then sand with a block so the repair feathers into the surrounding paint without a hard edge.

  4. 4
    Sand and refine

    Key the surface evenly and remove sanding dust before coating. Use guide or colour checking where it helps reveal scratches, low spots or uneven preparation.

  5. 5
    Prime and sand the base

    Apply the suitable primer or primer filler for the exposed substrate and repair depth, then sand the dried primer until the surface is smooth enough for colour.

  6. 6
    Apply the colour layer

    Apply the matched colour in controlled coats over the prepared base. Keep the repair edge soft so the new colour can visually blend with the surrounding finish.

Which rust repair and coating products should you choose?

Epoxy first on exposed metal

Use the EP primer method where the repair exposes bare or sensitive metal and needs corrosion resistant primer before the finishing build.

Filler depth

Use P 50 glass fibre filler for rougher damaged spots that need stronger filling, then P 99 where the panel needs smoother shaping.

Colour and clear finish

Use BC basecoat and CC 8 clearcoat after the repair and primer stages are stable, sanded and clean.

Technical details

  • Mipa EP Primer Surfacer is the stronger primer choice for prepared steel, aluminium and zinc areas.
  • EP primer components must be mixed with the specified hardener and thinner for that system.
  • Filler should not be used to hide rust that has not been removed.
  • Clearcoat is the final protective gloss layer and does not replace corrosion protection underneath.
Practical suggestion

If rust has perforated the metal or returned after earlier repairs, mechanical or welded metal repair may be needed before coating.

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