How to make concrete planter yourself? This guide will show you how to make concrete planters made of tape and cardboard. This example is for planters, but they could also be useful as storage boxes. This project is nice, because it’s cheap, fast and easy.
They pour concrete into a box … except for one thing – it should not be waterproof. The cardboard will suck the moisture out of the concrete and leave a chalky mass at the end. In the worst case, the cardboard will fall apart before the concrete has hardened.
beautiful flower boxes made of concrete
The solution to this problem is, of course, electrical tape. Gluing inside the box will make it waterproof and give some structure to the concrete as well. Gluing the carton edges to the corners will help strengthen the box and minimize the deflection under pressure that occurs during casting.
Materials + accessories:
• cardboard edge protection (90 degree curves)
• electrical tape (1/3 roll)
• CHENG Pro-formula concrete mix (Tahoe color)
• Sakrete 5000+ concrete mix
• Weights / Rocks / Sand / Something Heavy
How to make concrete planter yourself
• 5 gallon pails
• scoop / trowel
• Particle mask
• Rubber gloves
Step 1: Glue the boxes
What makes a good box for this project?
• Hard polyvinyl chloride / Relatively new
• Not too big (12 “x12” x12 “concrete weighs about 135+ pounds, think about the pressure)
Less than ideal:
• Thin cardboard
Find two boxes that fit in one another on all sides with a gap. More than 1 and the box can be quite heavy, less than 1 – which will not be so strong.
For the larger box (the main form):
1. Fold the flaps outward and glue them on.
2. Glue the inside edges of the box, especially the corners.
3. Tape the entire interior of the box with electrical tape, with some overlaps in each pattern where you want.
4. Stick the cardboard on the outside wherever possible to strengthen the box.
5. Decorate with leaves, stamps, tile pieces or with spray glue.
For the smaller box (the knockout):
1. Fold the flaps inwards.
2. Glue the outside of the box completely
Put the smaller box in the bigger one. Lift the smaller box until there is only one gap at the bottom. Make a mark on the small box with the edge of the larger one. When casting, this line will serve as a guide to let you know how deep you should press the smaller box down.