You may be shooting yourself in the foot with that turbo nozzle. With the high pressure you are driving water into the brick causing the salts to rise to the surface after you finish (efflorescence)
Is the efflorescence crystalline or powdery? It's really too hard to tell you what will work without seeing a picture and knowing what type of brick it is. Do a small sample spot with the hydrochloric again.
Start by wetting an area of brick 3'x3' with water. Apply the acid. If the efflorescence is crytalline it should start to bubble. Brush the area and let it dwell keeping it wet with acid solution. Rinse (LOW pressure like 300 psi). If it's still there, apply a second solution, brush again.
Put that turbo nozzle back in your toolbox. It's not the right tool for this job. |