Sun sails extend the time you can spend outside, protecting you from ultraviolet rays as well as minor bouts of rainy weather. To use a sun sail, you have to properly anchor it in place. Solid mounting with a series of stakes is fine if you don't intend to move the sail around, but if you occasionally want to put the sun sail elsewhere, you'll have to provide it with strong anchor points that you can move around.
Dump the bag of concrete mix into the wheelbarrow. A typical sun sail requires at least three anchors, so don't use more than a 60-pound bag of concrete.
Add water to the mixture, mixing until the concrete has attained the consistency of peanut butter. It doesn't have to be perfect; if you use too much water and the mix is slightly thin, it just takes slightly longer for the concrete to cure.
Fill the metal buckets all the way to the top with the concrete mixture.
Press a galvanized metal U-bolt into the concrete. This provides a place for the sun-sail rope to attach to the anchor. Allow the concrete to cure completely before using the anchors.
Anchoring the Sail
Tie the leader ropes to the sun sail's eyelets, located at each corner of the sail. Make certain the leader ropes are long enough to install the sun sail between two trees of your choosing. Leader ropes should be included in the package with the sun sail.
Throw one of the ropes over a tree branch, then attach one of the anchors to this rope.
Throw another rope that is attached to the sun sail over the branch of a nearby tree, then attach another anchor to this rope. Make certain the anchors both hold the sail taut enough to hold it in place.
Place the third anchor on the ground, then attach the sun sail's third corner to this anchor so this part of the sail is near the ground.