Treatment report for removing paints

This report is a prepared by Prakriti Bhandari as a part of an lab methods for the partial fulfillment of the requirements for the Master of Historic Preservation Degree at the University of Texas at Austin. Dec 2022

SUMMARY

This report was produced as a part of the requirements of a course Lab Methods undertaken during Fall 2022 semester of the University of Texas at Austin. The report is centered on the methods of treatment of the wall with a latex paint on it and recovering it back to it’s original lime wash painting.

This report includes a general architectural description of a building, it’s material pallette and the methods used for removing the paints and lastly the limewash techniques. There were three methods used in order to remove the white latex paint from the stone wall. Namely, manual hand scraping, using hot gun and lastly a wet sand blasting using walnut shells for sand blasting.

CLIENT: Guadalupe National Park

LOCATION: 400 Pine Cyn, Salt Flat, TX 79847

SUBJECT BUILDING: Frijole ranch Museum

Guadalupe National Park contacted the University of Texas at Austin and the University of New Mexico to repair and restore the ranch house, including the latex paint removal from the exterior native stone wall. Francisco Uviña-Contreras and Izabella Nuckles professors at both universities with a graduate student at the University of New Mexico and the university of Texas at Austin performed the treatment of the building in October 13-14th of 2022 on the East and North side exterior walls of Frijole Ranch Museum. It was a clear sky and 65-75 degree Fahrenheit while treatment was being performed.

Land/Lease Mapping Viewer

Land/Lease Mapping Viewer

Figure: Location map of the Ranch House

Land/Lease Mapping Viewer

11/9/2022, 9:30:56 PM

Frijole Ranch House

The Frijole Ranch Museum house is one and half story native ashlar stone masonry building with a timber dormer roof constructed in a vernacular style of West Texas. A rectangular plan house was first constructed in 1876 as a two-room house and eventually the outbuildings and the interior rooms were added to the original structure in 1925-26. The building complex has a spring house, barn,bunkhouse/guest house, school, and main house.

The south elevation is the front façade of the building and has an entry door at the center of the house and two windows each on either side. There is a timber dormer room with a window in the center of the house and on the southeast side of the Shingled roof. The southwest side window has a horizontal window joining both the door and window. All the door and window frame were painted white and small pane glasses were used in the shutter of the windows.This façade was cleaned already, and traditional stone masonry courses were visible(Stegner 1992).

Figure: frijole Ranch house current use as a musem

Figure: Frijole Ranch House South Elevation | Photo Courtsey: Cara Quigley

CHAPTER II - DESCRIPTION OF A BUILDING

Frijole Ranch House

The east elevation of the building has a gable wall and a window on the chimney’s northern side. The addition of the masonry wall is clearly visible due to changes in the stone masonry coursing and the size of the stone used. The added part on the north side of the house has a door on the eastern façade. This façade has a thick layer of white latex paint in it which needs to be removed. The roof of the later added kitchen room is low pitched and is covered with a green color.

Report - Frijole Ranch

Figure: Frijole Ranch House East Elevation | Photo Courtsey: Samantha Gilk

Figure: Chimney on the east elevation

CHAPTER II - DESCRIPTION OF A BUILDING

Frijole Ranch House

The northern façade has a later added structure which is used as a kitchen. The masonry stonework has rough rounded native stone while the corners have a corner tie dressed stone like the previous stone construction. The additional kitchen wall has three windows of comparable size and a door in the middle. The oldest structure has a dormer window on the sloping roof towards the eastern façade. Windows frame has a faded blue color paint.The paint on the masonry was already cleaned.

Report - Frijole Ranch

Figure: Corner stone masonry| Photo Courtsey: Samantha Gilk

Figure: Frijole Ranch House North Elevation with added kitchen| Photo Courtsey: Samantha Gilk

CHAPTER II - DESCRIPTION OF A BUILDING

Frijole Ranch House

The western façade has a gable wall with two windows in the center. Rare kitchen walls are not flushed on the western side with the original structure. The projected wall rare wall on the western side creates a room for the door on the southern side of the rare kitchen room.

Treatment Report - Frijole Ranch

Figure: Door | Photo Courtsey: Samantha Gilk

Figure: Frijole Ranch House West Elevation | Photo Courtsey: Samantha Gilk

CHAPTER II - DESCRIPTION OF A BUILDING

Material Pallete

The western façade has a gable wall with two windows in the center. Rare kitchen walls are not flushed on the western side with the original structure. The projected wall rare wall on the western side creates a room for the door on the southern side of the rare kitchen room.

Corner

Dressed Stone masonry- Earliest construction Wooden

The overall condition of the building looks fair. The stone masonry and shingle roof were intact and was maintaining the vernacular integrity of the building. The Eastern façade was painted with white latex paint which was to be removed for whitewashing the building. There were several treatment patches seen on the eastern façade of the building, most probably treatment was done to avoid moisture, some parts of the western façade have a loose mortar joint which needs repointing.

- Frijole Ranch

Figure: Frijole Ranch House’s stone masonry repair patches with the cement mortar | Photo Courtsey: Samantha Gilk

Figure: Masonry wall painted with latex paint| Photo Courtsey: Samantha Gilk

CHAPTER IV-CLEANING THE SURFACE

The eastern façade was treated, and several tools were used to remove the existing latex paint and they are:

1. Manually chipping of the paint using plastic scraper

2. Removing the paint using a hot heat gun

3. Sand blasting using walnut shells

Manually chipping of the paint using plastic scraper:

This is a slow tedious and safe process of removing the paint from the exterior wall by chipping the paint. The paint is scraped off with plastic tools. Even though this process takes time, it will not harm the building’s masonry structure. To collect the debris from the chipped paint, a plastic turf is first set on the ground. Then all protective gear is worn and only the process of scraping paints starts. The plastic scrapers should move in the same direction as the paint as they chip it.

The wastage that came out from the usage of the paint removing tools should be disposed safely using environmental standard.

Figure: Removing paint using plastic scraper | Photo Courtsey: Stefka Kuneva

Figure: Removing paint using plastic scraper | Photo Courtsey: Cara Quigley

CHAPTER IV-CLEANING THE SURFACE

Removing the paint using heat gun

• This method includes using the heat gun to remove the paint. The heat gun produces heat which helps the latex paint to melt and by using a metal scraper, the melted latex paint is removed from the surface. A N95 mask is worn while performing this task.

• First the heat gun is preheated at a temperature of 500 Degrees Fahrenheit.Hot gun is placed about 6-8 inches far from the masonry.

• Warm air preheats the surface and softens the paint

• Paint can be easily scraped off as soon as it is softened, and the gun is moved forward and the stripped surface is let cool.

The heat gun method should not be used on the surface which has a chance of getting damaged by the heat produced. Such as window frames The wastage that came out from the usage of the paint removing tools should be disposed safely using environmental standard.

Figure: Removing paint using Hot gun| Photo Courtsey: Stefka Kuneva

Figure: Removing paint on the wall| Photo Courtsey: Samantha Gilk

CHAPTER IV-CLEANING THE SURFACE

Removing the paint using wet sand blasting

Using pressured sand blasting on the surface, the paint is removed using this technique. To remove the paint off the masonry wall, a slow pressurized walnut shells and water jet is used. The paint gets removed faster with this method than with others since it is more aggressive. The old masonry is more likely to be harmed if there is too much pressure applied to remove the paint, thus it is best to use a modest intensity of pressure. A safety PPE has to be worn before starting this task.

• Fill the container with walnut sand, connect the sand blasting machine to the water supply with a hose, handle the other hose appropriately, and direct the hose toward the wall that needs its paint stripped.

• Turn on the water and the engine, which causes the mixture of walnut shell powder and water to move violently and strike the stonework, removing paints.

The wastage that came out from the usage of the paint removing tools should be disposed safely using environmental standard.

- Frijole Ranch

Figure: Removing paint on the wall using sand blasting| Photo Courtsey: Jiaxuan Hu

Figure: Removing paint using Hot gun| Photo Courtsey: https:// anglianblasting.com/blog/what-is-sandblasting-for-removing-

CHAPTER IV-CONSERVATION TREATMENT PERFORMED

After the paint is removed, Surface is prepared, windows were covered using a board and aTurf was also kept on the bottom to avoid the spall of the paint on floor.

Then a thin consistency lime wash is prepared and applied. While preparing the lime wash, a mucilage of the pikerly pear cactus was also added. The consistency of the paint should be in such a way that the solution will not break it is until 50 cm (about 1.64 ft) from the ground.

Thus, the prepared lime wash is painted on the removed paint wall by using a soft brush. First coat is applied in all vertical strokes and later another coat is applied in horizontal strokes. The alternate course of horizontal and vertical strokes should be repeated for at least 5-6 layers.

Once the whole layer of coating is done, the surfaces should be cleaned with water and brushes if necessary.

Report - Frijole Ranch

Figure: Professor Franscisco measuring the consistency of the Mucilage and water

Figure: First coat of Lime wash on wall | Jasmin Dickinson

Figure: After limewash | Lisa Hart

CHAPTER V- RECOMMENDATION

The life of the limewash will not be long so it should be timely maintained using the same methods. Using the least minimum intervention methods for the removal of the paint is highly recommended.

Report - Frijole Ranch

Figure: Before wall being treated | Photo Courtsey: Cara Quigley

Figure:After treatment of the wall | Jasmin Dickinson

Stegner, W. (1992) ‘Frijole Ranch’.