Guide to Limewater
Limewater is a clear solution of lime which was traditionally used by fresco painters as a binder for their pigments. In conservation it is used for strengthening the surface of fine grained limestones and lime plasters.
- Place approximately 100mm of mature lime putty (Buxton or Cheddar) in a parallel sided metal or plastic dustbin.
- 3/4 fill the bin with cold tap water and stir vigourously for 5 minutes.
- Place an airtight wood and polystyrene float on the limewater surface and leave to settle and clear for 24hrs.
- Place a wet hessian sacking around the bin to keep the limewater cool. Ensure the hession is kept wet.
- Draw off the limewater as required using a patent 'solo' spray pump attached to a clear polythene tube inserted 2" (50mm) into the limewater through a central hole. Alternatively the limewater can be drawn off into a portable garden spray (killaspray type).
- Wet the stone with one application of tap water prior to first application of limewater to aid its penetration.
- Ensure the limewater is water clear.
- Only apply to cool stone. Do not limewater stone that has been warmed by the sun and do not apply limewater in hot weather.
- Apply a floodcoat of limewater starting at the bottom of the area to be treated, moving sideways and upwards.
- Immediately after application sponge off any access limewater from the stonework surface using a clean sponge frequently rinsed in a bucket of clean water. This will prevent white limebloom from forming.
- Whenever possible do not let the stone dry out between applications.
- Eight applications per day is likely to be maximum attainable.
- Apply a total of 40 coats or until the rate of absorption by the stone surface has been significantly reduced.