Friday, June 15, 2012

A green substitute for muriatic acid wash

Apples, pears and oranges
Photo by Mark and Allegra Jaroski - Biava

An alternate name for muriatic acid is hydrochloric acid. A safe green substitute made of plants for this acid is found in certain potions and mixtures from witch doctors. What they actually used were some organic acids that are found in common plants. The two most effective acids are citric acid and oxalic acid, but don’t underestimate vinegar. In the course of things some of the other plant acids can also be used including vitamin C whose technical name is ascorbic acid. Any other plant acid will do..

Muriatic acid is used in the masonry trade to wash off any staining on the face of the masonry or stone caused by mortar used in a construction project. It is usually applied using a stiff brush an area that has been scrubbed with the brush is washed off immediately with clear water by starting to clean from the top of a structure and working your way down to the bottom.

In order to use the green substitutes effectively you should be wearing a bone through your nose along with some kind of feathers on your head. It was actually the witch doctors that discovered this in the first place. Until the invention of hydrochloric acid in the fifth century A.D. this was the only way they had of cleaning masonry. Another organic acid that was used during the pre-hydrochloric acid era was strong vinegar that is still used by many masons for cleaning mortar staining off masonry today.

The most effective organic acids for the job are a mixture of oxalic acid and citric acid these are easily made. Citric acid is nothing more than lemon juice. Oxalic acid can be recovered by steeping rhubarb leaves in boiling water like tea. Once you have extracted both of these acids from plants they are mixed together. This is also applied to masonry using a stiff brush to scrub with, and immediately afterwards the masonry is washed down with clear water.

The reason these plant acids are mixed is because oxalic acid itself will combine with the calcium in the mortar forming an insoluble compound called calcium oxalate. The addition of lemon juice to the oxalic acid works by the lemon juice keeping the calcium oxalate in suspension rather than letting it cling to the surface of the masonry being cleaned.

A mixture of oxalic and citric acid can also be used to chemically bore holes in marble or limestone using a method that dates back to antiquity.


Hydrochloric Acid, Wikipedia,

The disaggregation of stone materials with organic acids from plant extracts, an ancient and universal technique, Dr. Joseph Davidovits, Geopolymer Institute

Drilling a Hole in Stone with Fruit and Vegetable Juice, John Carter,

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