Would love to make my own pediments.?

Question

Concrete pediments must be easy to make by someone who has patience and a great artistic flare? Any important points for me to be aware of? Build lots so just need ideas on how to make best templates. Good with welding, construction etc. If I weld a form, how do I remove the pediment once it has set?

Answer 1

As stated they need to be in at least 2 parts bolted together more complicated may require up to 4 parts. Using standard form release is a no no this will permanently stain the surface of the concrete and not allow proper adhesion of what ever you want to put on it in the way of stain or color. Also it is not the water content that creates holes its air, yes the mixture cannot be to wet but it must be wet enough to "flow". Use pea gravel for the mixture or even bagged concrete mixture. I made some large planter that I made molds from and use the concrete mix from H D or Lowe's with fiber in it, worked good. The key to removing the bubbles is to vibrate the mixture a bit by tapping on the sides and top..but not to much because this will cause the rocks to settle. I have used a small random orbit sander before just touching it hear and there (without the sandpaper on) on the form this works very well also. You can use a strong mixture of liquid dish-washing soap and water in a pump sprayer and spray the form with this as a release, it will not stain and its very inexpensive. I have made several cast objects from concrete mostly pots but I have also made balustrade for my patio. I used the base of a plastic bird feeder I got from K-mart and split it in 2 reinforced it with a wood/metal frame and cast dozens of them.
Removing is just a matter of un-doing the forms. Depending on the size of the cast and the weather its best to wait at least 3 days before attempting this especially if you have allot of overhanging edges or accents...Its tough to wait because you want to see what it is going to look like but its not worth it. I have ruined many before I learned my lesson.

Answer 2

The form should be made in two parts then bolted together. Some pediments can be complicated. If you do make the form using metal, remember that the water in the mix can cause bubbles due to the chemical reaction, so the mix must be a little on the dry side. Don't forget to consider embedding some method of attaching the pediments to a structure, like bolts or holes for Tapcons.

Good luck.

Answer 3

They make concrete release products for any work that requires a form. It is an oil based product that does not allow the concrete to stick to a surface it is applied onto.