It’s been a long time since plaster was commonly used in home construction. Drywall became popular in the mid-50s and began taking over. It takes less craftsmanship to do drywall. The process took longer to put up lath, which was replaced by 2-foot-by-4-foot gypsum board, and then apply a brown coat and then a finish coat. Plaster, of course, provides a more rigid finish than drywall, which is one reason it cracks more often.
One advantage of some of the new latex paints is that the paint film remains flexible. Often times where there is a crack, even a hairline, there can be some minute movement between the two sides. This movement could crack some of the older paints that are less flexible. The textured paints are good for hiding many imperfections in surfaces, especially ceilings.
This is one reason the vast majority of drywall ceilings are covered with a very rough “popcorn” finish. This is, very simply, to hide the joints and nail dimples. Ceilings are much harder to finish smoothly than are walls. If your cracks are truly hairline, I believe the paint would do a satisfactory job for you.
If you decide to repair the cracks you find in your ceiling, I would do the following. Cut out a “V,” to widen the crack. Make sure you cut deep enough to go down to the lath occasionally. By doing this you can place a coated nail here and there along the crack. You should make sure the nail heads are below the surface of the plaster. Using this trick will help to reinforce the repair job and make it all hold together better. The nails provide a good solid footing for the plaster repair.
Let me also offer a few pointers about brushes and rollers. Innumerable painting aides are available for professional and novice painters; some are good _ many are not. It would take reams of paper to describe them all. I prefer the more tried and true tools like brushes and rollers. Some of the quality features I’ll describe about brushes and rollers can be applied to some of the new paint applicators, and then you can use your judgment to select the best.
Brushes vary in quality and their prices are usually proportional to a brush’s merit. Natural bristles are the most expensive because of their inherent characteristics. Bristles used in brushes have a long shaft and the end is “flagged.” A “flagged” bristle is one with an end that is naturally split into many fine hair-like pieces.
Some of the synthetic materials, such as nylon, come close to mimicking natural bristles in quality and price. Many have “flagged” bristle tips. The “flagged” or split ends allow for a smoother flow of paint or varnish (or whatever) with little or no brush marks.
Another feature of quality bristles is their ability to hold a load of paint and to release it gradually as the brush flexes against the surface being painted. Better quality brushes usually have three rows of bristles in the filler block. The filler block is the end of the brush handle that holds the brush fibers.
If you are looking at brushes, spread the bristles using the thumb and forefinger of both hands to check the number of rows and to determine how dense and resilient they are. Resiliency is how well they spring back into place. Softer bristles are best for thinner materials like stains and varnishes. Stiffer filaments handle oil and latex paints better.
Brushes come in a variety of shapes and sizes for specific purposes. Wedge shapes work well for cutting along edges. The names of most brushes — i.e., flat, sash and so forth, describe their uses rather well.
Most old timers agree that natural bristle brushes should be conditioned before they are used for the first time. I tend to agree with them. Conditioning is performed by suspending the brush in linseed oil deep enough to cover the entire brush head. Don’t set the brush with its bristles on the bottom of the container. Let the brush remain in the linseed oil for two or three days.
Take the brush out of the linseed oil, hold it between your two hands, palms facing, and spin out excess oil. Do this in a small cardboard box. The box will keep the oil from being flung all over you and the room you’re in. Next, wash the brush briefly in a solvent and twirl it again. This treatment will keep individual bristles from absorbing finishing materials that can reduce their resiliency.
Roller pads, like brushes, vary in quality and price for the same basic reasons. These are their ability to hold and deliver paint smoothly on to a surface. The nap or covering of a pad can have different fiber length and surface texture. The length of the nap is usually selected according to the surface to be painted. Rough or irregular areas require a longer nap. The length and roller pattern can also affect the surface texture of the paint when it dries.
With care, good brushes and rollers can last for many years and may prove to be the least expensive over time.