HDA – 76

Heavy duty stable caustic gel for masonry cleaning. Especially formulated to remove heavy and thick deposits of carbon, grease and oil from masonry, ideal for use before acid cleaning



Especially formulated to remove heavy and thick deposits of carbon, grease and oil from masonry, ideal for use before acid cleaning. HDA will also remove thick, multilayers of paint.

  • High level of caustic – quick acting
  • Removes even thick layers of carbon
  • Strips thick multilayer coats of paint
  • Keeps wet a long time – efficient
  • Clings to vertical surfaces


Appearance Thick clear gel


Use neat. No need to dilute.
NB Highly alkaline. Will attack paint, glass, aluminium and galvanised steel.


Always carry out a test clean of about 1m² this will enable the dwell time and other parameters to be determined. Block off access to foot traffic and make sure overspray cannot drift to cause a problem. Mask glass, painted surfaces, aluminium and galvanised steel. Shield plants, shrubs and trees. Remove all loose matter and prewet with clean water. Apply with a brick cleaning brush and work well into the surface. If it is to be left for more than 2 hours cover with polythene to prevent drying. Do not allow to dry. Apply with nylon brush on low pressure spray.


Rinsing is one of the most important operations in the entire cleaning procedure. The rinsing procedure that must be used to remove the dirt and the chemical requires a high pressure, low volume water pump at 6.9 mPa at 18 to 25 litres per minute, 69 BAR at 18 to 25 litres per minute, 1000 p.s.i. at 4 to 5 imperial gallons per minute. Use a 15 to 45° fan tip. Water at up to 70°C may improve cleaning but is not essential. The high-pressure water lance should be passed back and forth over the surface as if it were being spray painted. The nozzle should be held approximately 12 to 23 cm (5 to 9 inches) away from the surface, with the length of the back and forth pass limited to approximately 76 cm (30 inches). The contact time of high pressure rinsing should approximately 4 minutes per square metre(4 minutes per square yard). Complete rinsing is essential and should never be rushed. Special attention is required to prevent rinse water from accumulating on sills, ledges, etc. Rinse all scaffold poles and boards after cleaning is finished and ensure that they are clean. Re-apply for a second application if necessary. Rinse with Acid Neutraliser

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