Thursday, April 19, 2007

Still More on Plaster

This is from the book Victorian Interior Decoration 1830 to 1900

Painting walls or ceilings in the 19th Century required a hard finished surface or stuccoed wall, built up of 3 coats of plaster, with the final coat plaster of Paris, creating a perfectly smooth surface. New walls had to dry, or “season” for a year before being painted in oils; otherwise they would absorb the oil as they dried, giving an unsatisfactory, mottled finish. When the walls were ready the painter applied an average of 5 coats of paint, each composed of lead, pigments, and oil. The final coat was often thinned with turpentine to reduce the gloss.

Unlike oils, distemper paint, an opaque water color paint made from tempera, could be applied immediately to any newly plastered wall or ceiling – there was no need to wait for the surface to cure – and could also be applied to walls finished more cheaply in lime and sand. The American name for distemper paint was calcimine (or “kalsomine”). Distemper – calcimine – is closely related to “whitewash”, a finish based on whiting (finely ground chalk) and a solution of water, salt, and lime. The term whitewash should not be taken literally since coloring agents could be added to the mixture.

Distemper and whitewash had several advantages over oil-based paints. Because they were water based they were far less expensive. They could be applied immediately to new walls, and their drying time was rapid. They were relatively odorless. As they were fairly easy to work with, a skilled painter was not required to apply them. Critics also praised the flat or matte finish they produced. Because they could be applied to new hard-finished walls, they were often used as a temporary first coat.

The book I got that from breaks down the Victorian era by period, with each period usually separated in to decades. The above is from the first chapter, which is 1830 to 1850. It does seem that lime and gypsum were not completely exclusive, but were used together. According to that, the lime and sand plaster was used for the scratch and brown coats, and then the gypsum based plaster of Paris was used as the finish coat. It still indicates that walls needed a year to cure, even though the Preservation Brief says gypsum plaster cures in 3 weeks and that was one of the advantages over lime. More contradictions.

I found this line interesting:

distemper paint…could also be applied to walls finished more cheaply in lime and sand.

So it looks like maybe the Petch family took the cheap route and did not finish the walls with the gypsum based plaster of Paris finish coat. This kind of made sense, since most of the walls were papered. Only the kitchen and bathroom did not have wallpaper. The kitchen did have an 18-inch boarder, but the wall between the beadboard and boarder were “painted” plaster. Painted is in quotes because it seems it may have been distemper. Perhaps gypsum plaster was hard to get here, and if you’re going paper, why go to the trouble and expense to acquire it and apply it.

Also, when I moved the wall back in the bathroom and discovered the original “painted” plaster – it was a light blue color that I tried to duplicate – I always thought it looked odd. It looked more like the plaster was tinted blue, rather than a blue oil paint applied. The color was only on the surface, though. I now think this was distemper and not paint. I now wish I had repaired the original finished lime and sand coat and painted with distemper. Oh, well.

Oh, and the answer to yesterday’s question, “When was sheetrock invented” is, June 11, 1912. At least that’s the earliest patent date I have on the sheetrock that use used in my house in the late teens or 20s. When they added the bathroom to the kitchen they used sheetrock. On the back of each piece was a sticker with instructions for storing and hanging the sheetrock. At the bottom are a series of patent dates and the earliest one is June 11, 1912.

7 comments:

Catwoman said...

We are also restoring a house around the same age as yours, and yep we have horse hair plaster as well. It is nice to see someone else going through the same problems as us, and to know we are not the only ones that a doing renovations that do not go as smoothly as anticipated. :0

Anonymous said...

According to my dictionary distemper is only remotely related to whitewash. Distemper (literal translation from German: glue paint) is made of powdered white chalk, powdered white clay and cellulose glue similar to cheap wallpaper glue. Result: it is aways water soluble, to remove it just soak it with water and wash or scrape off.

Whitewash is basically lime putty with lots of water. It cures chemically and can't be washed off. It is usually applied to the wet plaster right after plastering and really bonds to the plaster.

Gypsum plaster is said not to be able to withstand ANY moisture.

gotta go, if you have questions ask.

Ragnar

Suzanne Courteau, aka Bones said...

Hey, what is the name of the book you got that from?

Greg said...

I highly recommend it. I bought it used through http://www.bookfinder.com/

Victorian Interior Decorations
American Interiors 1830-1900

Roger m. Moss & Gail Caskey Winkler

Published By Henry Holt & Co., Inc.

merideth said...

beth and i were just talking about this...getting into our bathroom walls, we found the expected plaster and lathe in some places but also what appears to be early early sheetrock in some places...it led us to wonder if this is what came between plaster and drywall on the wall-material lifecycle

Angus said...

Actually I believe Distemper is a latin word (at least with my good german knowledge I can see no connection to german glue or paint). As far as I know it's related to the Italian word 'Tempera' also a paint which I think means simply 'to soak', which would descibe how the paint works.

slateberry said...

I think some of the distemper rubbed off your kitchen walls and onto Mortimer. It soaked in and after a brief curing time it started to effloresce in quick bursts followed by periods of latent buildup.