Burning Lime, the Traditional Way

This is an incredible video that really shows the difficulties of burning limestone the old way. Stacking wood, limestone and coal in an old kiln these men go through the process using traditional methods to turn regular limestone into caustic burnt lime.

Use of Traditional Lime Paints (FAQ Friday with Randy Ruth)

This has been a crazy week here in the Northeast. First and earthquake then Steve Jobs and now hurricane Irene is coming for us. But Randy has another frequently asked question to answer today about the use of traditional lime paints.

Q: Isn’t lime paint an old technique for buildings? Aren’t there more modern options that will look better and last longer? 

A: Lime paint or as it is traditionally called whitewash is indeed an old technique for use on buildings, for both interior and exterior use. Lime Paint is made from slaked high calcium quicklime with a greater addition of water than what would be used to make lime putty. The resulting product has a consistency of thin milk.

Lime Paint is used on the exterior of buildings as a sacrificial breathable protective coating over lime render, brick, concrete, adobe, stone and earthen structures. By applying multiple thin coats of Lime Paint, each coat reacts with carbon dioxide in the atmosphere to convert back to calcium  carbonate, also known as limestone. This technology has been around since before the construction of the great pyramids in Egypt, where lime was used in mortar formulations. 

There are some limitations to using Lime Paint in modern times, most likely because of the expectations people have from today’s common latex paints. Although, Lime Paints do wear away, can sometimes chalk when rubbed and cannot always achieve the same brilliance of modern paints , they do have some wonderful properties that make their use appropriate for modern applications.

Lime in of itself reflects light in a such a special way that we get the term “limelight” from its use in early stage lighting techniques. The colors that can be achieved with Lime Paint are more of an earth tone and give off a warm glow that modern latex cannot provide. Since Lime Paint is mineral based it does not peel or flake, it simply wears down.

When a “breathing” wall needs to be protected or decorated with a paint or stain, Lime Paints provide the breathability suitable for the wall. However when a tougher more durable coating is required silicate paints and stains can be used.

Silicate paints are mineral paints made from either sodium silicate or potassium silicate and chemically bond to a masonry substrate, through the chemical act of petrifaction. This allows a paint that can also not peel or flake due to the laws of chemistry, similarly to Lime Paints. Silicate paints were originally made during the mid 19^th century in Europe and have since been refined to become some of the best paint for use with masonry. They can reach a wider range of colors when compared to Lime Paint. Although silicate paints may last longer with less maintenance it does not particularly make them better than Lime Paints.

Someone who wants an “aged” look or even the more natural feel of lime would think Lime Paint is a better choice over silicate. For a muralist who does not want to be bound by a limited color range and needs the durability of silicate in a city environment, then silicate paints are a no brainer. At the end of the day, when choosing a breathable, historically proven paint for a building, one must weigh the pros and cons of each paint when compared to the demands of the project at hand .

 

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)