1 · What is happening at this step
Applied body filler is shaped and levelled until the panel contour is right, then feathered into the surrounding primer and paint so the repair area cannot be found later. The work is done with a hand block, with a machine on a soft pad, or with both — machine for removal, block for flatness.
[TO CONFIRM: image — process photograph of filler shaping with a sanding block, own material or authorised only, registered in ../assets/_manifest.md]
2 · What usually goes wrong
The abrasive loads. Filler is soft and chalky, and it packs into the space between abrasive grains quickly — worse when the filler is not fully cured, when pressure is high, or when the abrasive carries no anti-loading treatment. A loaded disc stops cutting and starts polishing, which leaves a glazed skin that primer will not grip. This is the single most common complaint at this step.
The work is done outside the cure window. Filler sanded too early gums up and pulls out of the repair. Filler left too long hardens and cuts slowly, so the operator presses harder, and pressing harder rounds the edges. The window moves with shop temperature and catalyst ratio, so it is not the same in winter as in summer.
Edges and body lines round over. A machine with a firm pad tilts at the panel edge and takes the sharp line off. Once a contour is gone it cannot be sanded back in — it has to be filled again. Crown lines, panel edges and wheel arch lips are finished by hand, or on a soft interface, for exactly this reason.
Ripples appear after painting. Hand sanding without a block follows the shape of the hand, not the shape of the panel. The ripples are invisible in bare filler and obvious in gloss. A guide coat applied before the final stages is the only reliable way to see them while there is still time to correct them.
The scratch left behind is too deep for primer to fill. Whatever scratch pattern remains at the end of filler sanding has to be refined out before the topcoat, or it swells and reads as visible lines — worst on dark solid colours. Finishing this stage one step too coarse is the usual cause, and the cost shows up two stages later.
3 · What this step uses
POLIRITE F-Series — abrasives for body filler shaping and levelling
[TO CONFIRM: series designation pending finalization]
Intended for machine and hand sanding of polyester filler and glazing putty, with an emphasis on resistance to loading and on maintaining panel flatness.
- Formats supplied: [TO CONFIRM: which of disc / sheet / roll / strip are actually available]
- Abrasive grain: [TO CONFIRM: available grain types]
- Grit range: [TO CONFIRM: available grit range, and whether P-grade or CAMI]
- Backing: [TO CONFIRM: paper weight, film or cloth backing options]
- Anti-loading treatment: [TO CONFIRM: whether a stearate / anti-loading coating is applied]
- Disc diameters: [TO CONFIRM: available diameters in mm]
- Hole patterns: [TO CONFIRM: dust extraction hole patterns and hole count]
- Attachment: [TO CONFIRM: hook-and-loop or pressure-sensitive adhesive]
- Recommended grit progression for filler work: [TO CONFIRM: progression to be confirmed with the factory, do not state a typical progression as ours]
Accessories used at this step
- Hand sanding blocks: [TO CONFIRM: whether supplied, and available lengths and hardness]
- Interface pads for edges and contours: [TO CONFIRM: whether supplied, and available thickness]
Supply terms for products on this page
– MOQ: [TO CONFIRM: MOQ per format]
– Lead time: [TO CONFIRM: lead time in days after receipt of deposit]
– Packaging: [TO CONFIRM: pieces per box, boxes per carton, carton dimensions and weight]
– Customisation: [TO CONFIRM: private label, custom sizes and custom hole patterns]
– Samples: [TO CONFIRM: sample policy for this range]
[TO CONFIRM: image — product close-up, in-use photograph and packaging photograph for each series above, own material or authorised only, registered in ../assets/_manifest.md]
4 · Request a quote
Tell us the filler you use, your shop temperature and cure time, whether you finish by hand or machine, and the grit progression you run today.
Button: Request a quote → /contact/
Form prefill hint: Filler type (polyester / glazing putty) · Cure time at your shop temperature · Hand block or machine · Current grit progression · Monthly usage