What type of Concrete?

[JKimel]

Hey,

What kind of concrete could I use for filling very small forms (about 4" x 4") with small corners that the concrete would need to get into?

I'm concerned that regular concrete would not work due to the form and corners being too small.

I still want the weight that concrete gives.  I thought a cement would better.

[Roly]

Hey,

What kind of concrete could I use for filling very small forms (about 4" x 4") with small corners that the concrete would need to get into?

I'm concerned that regular concrete would not work due to the form and corners being too small.

I still want the weight that concrete gives.  I thought a cement would better.

That cement sets up very fast which may be a problem.   What about a Sand/Topping mix,   No large gravel .   Roly

[woodhead]

That cement sets up very fast which may be a problem.   What about a Sand/Topping mix,   No large gravel .   Roly

Yea, sand mix!  The topping mix has more cement in it and maybe some bonding agent and Roly is correct!


Al

[blackhat]

What purpose will the final object serve?  Topping cement has a few drawbacks depending on the environment and usage.

[Phil Thien]

Curious as to what you're up to.

[Mr_Mike]

I would blend my own sand mix. Its pretty simple. I'd also vibrate the forms with a Random Orbit Sander to setting the concrete into the corners.

I blend my own when I do counter tops. I use a high ratio of cement to sand. For the counter tops, of course, I use wire mesh or rebar (or both) as well.

[Roly]

I was wondering if floor leveling compound would work.    As said, a lot depends on the intended conditions for it to be used in.   Roly

[JKimel]

The form looks like 2 pyramids stuck together back to back.  total length is about 5" x 4".  This will see little stresses so I don't think I need r/f.  It's a decorative item so I need the faces to be super smooth.  I've heard the vibrating with a reciprocating saw without the blade works well too.  

The sand topping mixes I see are stated 1.5" max.  So I'm thinking Portland Cement mixed with sand added at a 1:3 ratio?

Thanks for pointing me in the right direction with this.  I've never used concrete for decorative purposes before.

[JKimel]

[Mr_Mike]

Heck, that small, he could put it in a bell jar and get all the air out.