Is it possible to scale a concrete pour? As is doing a cast concrete scale building? I figure you could make ultra fine cement be putting it through a makeshift ball mill. Maybe a ruck tumbler filled with steel shot. As far as aggregate goes I’m sure some trial and error could figure that out. Does anybody have any suggestions?

Ray Dunakin’s ( In Ko Pa Railroad fame)stone buildings use a similar method. Stonework with a mesh and mortar poured backing. For concrete in scale, mortar mix would be a scale aggregate. I’ve had success with exterior grout which just seems to have a better texture for 1/29th usage.

If I were to add aggregate I’d think along the lines of 1/4" minus or smaller and sift for the smaller pieces.

Sweet! I was really hoping this would work. I need to do some Cold War era Russian buildings and I think this would be perfect. Thank you!

What Dave said. Even finer than Mortar Mix is the Patching Cement that comes in small plastic pails. It works great for small molds, Just be sure tio use some type of mold release on your forms. Silicone spray works good on wood.

Here’s an article on cement buildings on our club website.

http://www.backyardrailroaders.com/tips.html

The folks who do these things, Jim and Julie Barber, have made a lot of 'em and have experimented with several different concrete formulae to arrive at their present one, which they are very happy with. They talked to me about it at the last meeting, but I can’t remember what they said the best formula was, but it’s a simple mixture of a couple of premixes from Lowes or wherever. You can contact them and ask away.

Thanks John - That is a very nifty idea. The engine house at the end looks great.