'G Force' Scratch Repair Polishing System

This test was carried out on a machine current in 1998. Since then we have continually developed, improved and updated our scratch polishing system which has evolved into the current G Force Scratch Polishing System.

BSI Report Dated 18 December 1998 - Report No. 262/005511

At the request of Glas-Weld Systems, the Scratch Repair Polishing System was tested to the procedure as laid down in this Report:

Test Items
  • Polishing System: Part No. 10004
  • 4" Polishing Disc: Part No. 1402 / Lot No. 06268
  • Polishing Compound: Part No. 1406 / Lot No. 08208

A sample of 1100x500mm laminated glass 6.76mm thick was placed on an optical stand used for testing windscreens to ECE Regulation43 and the rake angle set to 55°.

The glass was firstly assessed for optical distortion (ECE Reg.43) and this method entails the projection of an appropriate slide (raster) onto the display screen through the safety-glass pane being tested. The change caused in the shape of the projected image by the insertion of the safety-glass pane in the line of light provides a measure of distortion. This test was repeated after the scratch had been polished.

The next test conducted was the optical deviation test (ECE Reg.43) with the safety-glass pane mounted at the specified rake angle in such a way that the observation is carried out in the horizontal plane passing through the centre of the target.

The light box was viewed in a semi dark room through each part of the area being examined, in order to detect the presence of any secondary image associated with the illuminated target. This test was repeated after the scratch had been polished.

To generate the scratch on the glass, a 1.042kg steel ball was rested on a piece of 44 grit abrasive paper. This was then passed 10 times over an area 350mm long. The scratched test piece was then subjected to the distortion and deviation tests.

Results Distortion Deviation
Undamaged Sample None None
Scratched Sample No distortion but a feint line on the display screen Deviation exceeding the limits of ECE Reg.43
Polished Sample None None


- P.Parkins, BSi Product Services, Maylands Avenue, Hemel Hempstead, Hertfordshire HP2 2SQ