White concrete or similar

[Johan Gunverth]

I am considering testing window sills made of white concrete or a similar material. The idea is to have a moisture-resistant material that resembles the white trim as closely as possible. One of the sills is situated directly in front of the sink. Marble is not an option as the pattern in the otherwise beautiful stone clashes too much with the rest of the kitchen. I have also looked at medium gray Kinnekulle limestone which might work. The color is "correct" but is significantly darker than the rest of the kitchen.

What material is required to cast white, mineral-like, and relatively strong and dense?

 

[jon_h]

Fun idea.

Well, to start with, you need to use white cement, and then a white aggregate. Not sure if maybe crushed marble would be suitable?

Edit: Now I'm brainstorming even more, crushed dolomite might work too?

Edit2: You write that it should be as similar to the wooden frames as possible. You can always paint the concrete in the same color.

 

[Johan Gunverth]

Fun idea.

Well, to start with, you'll need to use white cement and then a white aggregate. Maybe crushed marble could be suitable?

Edit: Now I'm brainstorming even more, crushed dolomite might work too?

Edit2: You write that it should be as similar to the wooden reveals as possible. You can always paint the concrete in the same color.

Great tips!

You could go with the terrazzo variant, but without the contrast between the cement and crushed marble.
I'm somewhat skeptical about painting. Can it really hold up? On the other hand, I do have access to mineral pigments (silicate paint from Flügger) and you could enhance the whiteness with that. It might even be titanium dioxide. Then you should treat the concrete with waterglass properly before polishing it.

The casting will also include a bröstlist and will therefore be in the form of an L-profile.

 

[jon_h]

You can always paint with a 2-component paint mixed to the right color. It will definitely hold. I don't know much about paint, so I can't comment on the durability of the other options.