How to make a concrete Post Cap

Preparing the form

Leveling the mold

The lower part of the mold [m1] was packed level on the ground.
The upper part of the mold [m2] was placed on top.

Some strips of woodTimber, lumber. The hard fibrous lignified substance under the bark of trees [m4] were screwed around the top of the lower mold [m1] to hold the upper part of the mold [m2] in place.

Applying oil and diesel to the mold again

The top part of the mold [m2] was removed and another coat of used car oil and diesel mixture was applied to the inside of the mold.

Any excess was wiped off with a rag.

Clamping the mold shut

The top part of the mold [m2] was then put back in place on top of the bottom part of the mold [m1] and clamped tight.

Placing concreteA mixture of sand, gravel, water and cement which hardens to a stone like condition when dry. into the mold

Wet concrete was then placed inside the mold.

For information on how to mix concrete click here

The concrete was poked continuously a few times after each shovel-full to help get rid of any air pockets and make the outsides of the concrete smooth.

All the concrete in

When the mold was full, the wet concrete was again poked repeatedly with a stick to settle the concrete, get rid of any air pockets and make the concrete nice and smooth against the mold.

The outside of the mold was also repeatedly tapped with a hammer, making vibrations to settle the wet concrete even more.

The unveiling

The mold containing the concrete was left in the shade, covered with wet or damp cloths and left for about four or five days to allow for curingThe hardening of concrete. The process of becoming hard or solid by cooling or drying or crystallization. In concrete application, the process in which mortar and concrete harden. The length of time is dependent upon the type of cement, mix proportion, required strength, size and shape of the concrete section, weather and future exposure conditions. The period may be 3 weeks or longer for lean concrete mixtures used in structures such as dams or it may be only a few days for richer mixes. Favorable curing temperatures range from 50 to 70 degrees F. Design strength is achieved in 28 days. and minimize the risk of cracking.

The clamps were then taken off, and the top part of the mold [m2] came away with ease. The capCover was then turned upside down, screws at two corners of the lower mold [m1] were taken out and the rest of the mold came away, also with ease.

The concrete finish wasn’t too bad. There were a few small air pockets around the outside but it was perfect for the rustic look that was wanted.

The mold was cleaned, re-brushed with oil and diesel, put back together again and used to make another two concrete caps.

When the caps were taken out of the mold, they were left for another few days to further harden just to ensure that no edges would be damaged while handling.