Halo rings

weberpral M is designed as a one coat material, to be applied in one or two passes to achieve a single monolithic coat. Problems occur when passes are applied at an inappropriate thickness. 

When applying weberpral M (or weberpral D) the passes must be applied at approximately equal thicknesses or the first pass just thinner than the top pass. Problems occur when the second pass is applied as a thin coat over the first. In this case, during the scraping process, the laitance layer is exposed and a halo ring or snake is produced. The texture will alter across the face of the lighter area as this is basically the fines of the laitance layer. The effect is more likely to occur by the application of wetter than necessary mixes. Further scraping at the lighter line will only move the snake or enlarge the halo ring.


There is very little that can be done if the workmanship is deemed unacceptable other than to add an additional coat of weberpral M (or weberpral D).

  • Brush the area down and remove any loose materials, clean with a mild detergent or biocide wash if needed, allow to dry.
  • Re-set details utilising a 10mm profile bead, fix with weberend aid or weberend bead adhesive.
  • Apply weberend aid at 2-3mm and stipple using a brush or loaded roller, allow to cure for at least 48 hours.
  • Apply a 10mm-12mm pass of weberpral M and finish accordingly.

Alternatively and where appropriate, a stage 2 repair can be carried out.

Contact us

If you have any questions or would like assistance, please contact our technical team:

Our technical team is available Monday to Friday, 8:30am until 5.00pm.

Click Compare to help you choose the right product for your project, if you need further assistance please email technical@netweber.co.uk