Buying the raw materials, gravel, Portland cement and sand is considerably cheaper than buying pre-mixed concrete patching. If you are patching a deep hole, you can use 1-inch (2. 54-cm) gravel, otherwise, use very fine gravel. Mix the dry materials in a ratio of 3 parts gravel to 2 parts sand to 1. 5 parts cement in a bucket. This is sometimes listed as 3 to 2 to 1. A higher amount of cement will create a stronger material. There will be more of chemical reaction between the cement and water, which will create more crystals and a harder structure.
This will stop the porous concrete from sucking the moisture out of the bonding agent and concrete bonding material.
You can also buy an acrylic bonding agent to use in place of the homemade cement paint. They are made of resin and can be either added to your patching concrete or applied like the cement paint. Follow the instructions on the can or bottle very carefully, as many of the products have different application instructions and drying times.
