Importance of Compression
As our saying goes: "For your walls to impress, you must compress!" Compression is the final and most critical step in our application process.
After the finish coat is completely dry, you must use one of the compression techniques described in this section. The compression step stabilizes the surface, prevents dusting, and helps to even out color variations in the plaster. This process also makes the finish surface repairable.
Your compression choice will also effect your plaster surfaces final look and feel, so be sure to select the appropriate technique for the plaster
finish you wish to achieve.
Sponge Compression
After the wall has completely dried, rub the surface with a tile sponge using varying circular-like strokes utilizing a slight amount of pressure. The tile sponge should be damp, not dripping with water. To remove excess water from the sponge, wring it out as best as possible.
If the wall gets too wet, the color will lighten (causing discoloration) as the sponge rubs the surface. Stop rubbing and allow the wall to dry for a short period of time. Wring out your sponge prior to continuing if the problem persists. Also, if the wall surface is too wet, you may begin to bring the larger aggregates of the plaster to the surface, creating a rougher, textured finish.
As you move across the wall, the tile sponge will become dry and will begin to accumulate pigment on the surface. Simply, dip your sponge into a bucket of water and wring it out before resuming compression.
Sponge compression can be completed on any of our plasters:
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If used on a smoother finish, the surface will become more matte.
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If used on a rougher finish, the surface will feel slightly rough. You will also need to brush any excess sand off the wall as you go with a brush or dry tile sponge.
Sponge compression, especially on a smoother surface, also tends to bring out the "sparkle" of the sand aggregates.
The final surface should be stable and not sandy or dusty when you finish.
Hard Trowel Compression for a Matte or Smooth Finish
After the wall is dry, lightly mist the plaster so the surface is fully damp (no dry spots remain) but water is not running down the wall.
Using a stainless steel or Lexan plastic trowel*, trowel the surface using small, half-moon type motions. Your trowel should be at a slight angle off the surface, not completely flat. The trowel should glide across the plaster and no scratching sounds should be audible. If scratching from the trowel is heard, the wall is too dry, re-mist before continuing.
*Note: A Lexan plastic trowel is recommended for compression with Lomalina™, Porcelina™, Forté Finish, and Forté White finishes. When using a stainless steel trowel with these finishes, especially in lighter colors, metal burn marks from the trowel are left on the surface causing discoloration.
Mist and repeat as needed until you have completed compression on the entire wall. Working in a two foot by two foot section or smaller is recommended. The wall should feel smooth to the touch after troweling.
If you use too much water during compression, the plaster surface will begin to create a slurry of material. This is known as "raising the cream". Let the cream absorb back into the wall, and continue troweling. If this is a issue, mist less, or use a finer mist, to prevent this problem in the future. A small amount of cream is normal and can easily be worked back into the wall.
If your wall is excessively wet your trowel may begin to feel sticky to the surface, sometimes enough to trap the trowel onto the plaster. This can cause the plaster to delaminate from the previous plaster coat or substrate underneath when removing the trowel from the wall. If you start to pull or remove material from the surface, stop immediately and let the surface dry completely before resuming compression.
If large amounts of cream or dust are left on the surface, the wall will be lighter in color and leave irregular coloration behind. This is difficult to remedy and may result in the need to re-compress your surface.
If you have small amounts of cream or dust on the surface after your wall completely dries, you can correct any discoloration by using a lightly damp clean microfiber cloth. Using varying circular-like strokes, lightly buff the surface to remove from the wall. Repeat as necessary.
Hard trowel compression can be completed on any of our plasters.
The wall should feel smooth and stable, not sandy or dusty when you finish.
Questions About Compression
If you have questions about the compression process, or need a fuller explanation of how to do it effectively, please call 1-866-404-1634 (toll-free technical support line) for further information.
Please continue with the guided Online Workshop steps below:
Please note: The guidelines outlined in these instructions are provided as a source for general application procedures. We are not responsible for the results of your project. The only way to ensure a proper application is with due diligence on your part. If you have questions or are unsure of anything, please call 1-866-404-1634 (toll-free technical support line) for further information.