- 1). Run a putty knife over the old lime mortar that is loose and scrape it off. Scrape the knife over the entire surface and brush up the dust and other debris from the mortar with a broom and dust pan.
- 2). Wipe down the surface with a damp, clean rag. Scrub thoroughly and remove any leftover debris with the rag so the surface is smooth and even throughout.
- 3). Pour 9 oz. of water into a plastic spray bottle and mix it with 1 oz.muriatic acid. Stir the mixture around so it mixes together and add more water and mortar, if necessary. It must always be nine parts water and one part muriatic acid.
- 4). Shut the lid on the plastic spray bottle and position the bottle next to the old lime mortar you want to dissolve. Position it about 4 inches from the surface. Press the trigger on the spray bottle and begin spraying the mortar with the mix.
- 5). Cover the entire surface and wait 15 minutes for it to begin to dissolve. Scrub off the dissolving mortar with a scrub brush and continue in the same manner until all of the mortar is removed. Rinse the surface with a clean rag and water.
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