Posts Tagged ‘Alis Clay Paint’
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15 December 2009
Alis Coat – Sunshine Yellow
This alis coat was applied over the brown coat of plaster. This is a variation from painting the alis after doing three coats of plaster (scratch, brown, and finish). After a bit of tweaking, the results were beautiful.
In an effort to save labour costs for the owners, we experimented with time saving measures when applying the plaster to the straw bale walls. The first coat on the bales with a sprayed clay slip, and the second coat was a thick brown coat that was troweled and then hard troweled to shape and smooth the walls.
The alis coat was to be applied directly onto the brown coat of plaster, but we found that darker bits of horse manure were showing through and discolouring the alis. The brown coat also changed the colour of the alis slightly, adding a yellow tinge.
To solve this problem, we tested using wheat paste (flour and water) under the alis coat, with excellent results. So we used a paint roller to apply the wheat paste onto the walls, which is a relatively quick and easy process, then brushed on two coats of alis. The alis no longer showed any discolouration, and we were able to achieve the deep sunshine yellow colour that the owners wanted.
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11 December 2009
Mixing Alis Clay Paint
Alis clay paint is made up of clay, aggregate, and water. Pigments, such as powdered minerals or oxides, can be added for colour.
Often kaolin clay is used in alis because it has a fine consistency and a white colour that does not affect the final colour of the paint. Silica sand can be used as the aggregate, or mica can be substituted. Fine ground mica adds an overall sparkle to the alis, whereas larger pieces of mica look almost like irridescent fish scales scattered over the wall. Straw chopped into very small pieces can be added to an alis paint to give another variation in the final appearance.
Handling ingredients safely is important. Mineral and oxide pigments may be natural, but that doesn’t mean that they are non-toxic if inhaled. A dust mask is essential when combining the alis ingredients with water, as they can become airborne during the mixing process.
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2 December 2009
Alis Coat Beside Earthen Plaster
This photo shows the contrast between the smooth alis clay paint and the texture of the coloured earthen plaster. The powdered mica in this alis gives it a shiny finish, whereas the earthen plaster is a matte finish with texturing from the trowel application.
The young boy whose bedroom this is had one request for the wall colour: “green”. The parents decided to have the two drywall walls done in a strong avocado green plaster to satisfy the “green” request. The two straw bale walls were finished with pale lily green alis paint to brighten the room, which is situated on the northwest corner of the house and doesn’t receive much natural light, especially in the winter.
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24 November 2009
Alis Coat – Pale Lily Green
The shine in this alis coat is achieved by adding mica to the mixture instead of silica sand as the aggregate. The mica reflects light, and different sizes of mica in the alis paint will give different results.
Flakes of mica in the alis coat look almost like irridescent fish scales scattered throughout the paint. Finer ground mica in the alis coat will sparkle in the light. The effect over a whole wall or room is stunning.
The plaster doesn’t butt up to the timbers but goes behind them and meets with 2x4s that were nailed to the exterior of the timbers prior to the straw baling phase. Where the plaster meets wood, it can crack slightly and pull away from the wood with fluctuations in humidity. We wanted any cracks to happen behind the timbers where you wouldn’t see them. Because of this, applying the alis posed a challenge, as we needed to paint behind all the timbers and braces.
We used portable cardboard masking and much smaller brushes with long handles to get behind the timbers and braces. Any alis that got onto the timbers by accident will just rub off with water on a rag. The timbers should be cleaned soon after the alis is finished, not because the paint is permanent, but because as the wood changes colour with UV exposure, it will change differently under any alis on the wood and leave noticeable colour variations.
