The University of Michigan Detroit Observatory: "
The recipe for the stucco finish of many of the University buildings, including the Detroit Observatory, the four professors' houses, and the North and South College buildings, as well as other Ann Arbor buildings, such as the Lund house on Pontiac Trail, can be found in Dr. Chase's Recipes; or Information for Everybody. This book, published in Ann Arbor, was an international best-seller for several decades. The recipe can also be found on page 102 and 103 in A Creation of His Own: Tappan's Detroit Observatory, by Patricia S. Whitesell. The fascinating recipe in its full detail follows:
First make up as much mortar as you need for the job, with good common lime; using only 3/4 or four-fifths, at most, as much lime as needed for common work--the other fourth or fifth is to be water lime; and not to be put in only as used. The sand must be course and free from loam or dirt.
To prepare the white colored washes, run off common lime enough with hot water, to make a white-wash to go over the whole job. This white-wash is to be colored the tint desired for the work. Be sure to make color-wash enough at one time, or you will find it hard to get the shades alike; saving a little of the white-wash without color, to pencil the seams, and also for specking, as mentioned below. The colors used are lamp-black, Spanish brown, or Venetian-red, as preferred, and these are cut or dissolved in whisky; then putting into the white-wash to suit.
When these washes are all prepared, wet up as much of the mortar as can be put on in 20 to 40 minutes, and mix in the fourth or fifth of cement, and put on as fast as possible; first wetting the wall very wet with water. Some cement will set in 20 and some in 40 to 50 minutes. When you see the time necessary for the kind you are using, act accordingly, and only mix the cement into as much mortar as your help will put on before it sets; beginning at the top of the wall with your scaffolding and working down, which prevents too much specking from the colors. Have a man follow right after with a float, keeping the stucco very wet while floating down level and smooth; and the longer it is floated and wet the better will be the job. Even after it is floated down well, keep a man wetting it with a brush until you get the whole line on, as the water-lime must be kept quite wet for some considerable time, to set properly. Heed this caution, and if water never gets in behind the plastering from bad cornice or leaky roofs, it will never peel off. When this line of scaffolding is plastered, take out enough of the color-wash, running it through a sieve, and go over the plastering; lamp-black alone gives it a bluish-slate color; if a little of the brown is added with the black, it will be a little reddish, and if the red is used without the brown, it will be quite red. I prefer sufficient of the black only to make a gray stone color. A brown, however, looks exceedingly well. If you choose, you can make one-half of the color-wash darker than the other--having laid it off into blocks resembling stone, by means of a straight-edge, and a piece of board about half an inch thick, paint every other block with the darker wash to represent different shades of stone. Some of our best buildings are done this way and look well.
Then to give it a granite appearance; take a small paintbrush and dip it into the white-wash, saved for this purpose; strike it across a hammer-handle so as to throw the specks from the brush upon the wall, then the same with black and red. Pencil the seams with the white-wash, which gives it the appearance of mortar, as in real stone-work.
Now you are ready to move down the scaffold, and go over the same thing as before. After the colors have been dissolved with spirits, they can be reduced with water, or what is better for them and the color-wash also, is skimmed-milk; and where milk is plenty, it ought to be used in place of water, for white-wash or color-washes, as it helps to resist the weather and prevents the colors from fading... Speck quite freely with the white, then about half as much with the black, and then rather free again with the red. The proportion of lime, probably, should not exceed one, to six or seven of sand.
Household Products Database:
Chemical makeup of stucco
Calcium carbonate 15 percent
Silica (Quartz) 50 percent
Portland cement 35 percent
Pages 1--29 from handbook: "Truisms are statements that are usually true.
In formulating stucco mixes, everything is a compromise. By understanding what the compromises are, when a problem develops it is easier to solve the problem.
USE OF LIME
The higher the absorption of a wall,
the greater the need for lime to maintain a high water retention.
The higher the lime, the greater the workability.
The higher the lime, the less the bleed water.
The higher the lime, the more open time for working the mix and the longer before the next coat can be applied.
The higher the lime, the lower the ultimate strength.
The higher the lime, the higher the carrying capacity for sand.
USE OF CEMENT
The higher the portland cement, the greater the initial strength.
The higher the portland cement, the greater the final strength.
The higher the portland cement, the greater the likelihood of plastic shrinkage cracks.
The higher the portland cement, the sooner the second coat can be applied.
USE OF SAND
The lower the sand, the greater the strength.
The lower the sand, the greater the cost per cubic yard of prepared stucco.
The higher the sand, the less the likelihood of plastic shrinkage cracks.
The lower the sand, the greater the workability.
The coarser the sand, the less the likelihood of plastic shrinkage cracks.
The coarser the sand, the less the workability.
Welcome to The Lime Centre: "Universally during the past 25 years there has been an increasing awareness of the importance of lime in historic architecture and, in particular, it's use in conservation. A number of authoritative bodies such as English Heritage, the Building Research Establishment, the Society for the Protection of Ancient Buildings and the Standing Joint Committee on Recruitment and Training of Architects for the Care of Old Buildings, have produced and published a great deal of valuable academic work on the subject.
Stucco news-info on stucco and plaster-expansion joints: About 25 years ago I had a house with white california stucco on it. The stucco job was a poor job and needed to be sealed. My uncle who is 88 years old used to work for a local cement company here and had given me
a formula for sealing and whitening california stucco. Over the years I have lost the formula and am in need of it for a friend with a similar problem. To the best of my recollection the formula consisted of
-3 gallons of luke warm water mixed with 3 lb. of salt
-10 lb. of hot lime mixed gradually into the luke warm water
-1 lb of clear paraffin wax poured in during the process of mixing the hot lime and the water
-1 lb of lard melted and pored in during the mixing process
The above were mixed in a metal container as the mixture becomes quite hot during the process. Once finished and the mixture is cooled it can be stored in plastic containers and sealed. The mixture remains in this state until ready to be used. When ready to use take 1 gallon of the formula and mix in 10 lb. of white portland cement, use electric paddle to thoroughly mix. Apply the resulting mix with a whitewash brush to the stucco. The stucco should be wet when applying as this encourages the mix to penetrate into the stucco. The end result is a brilliant waterproof mixture that lasts for years. This mixture can also be applied to colored stucco and the end result is a brilliant white finish that is an unbelievably waterproof finish.