To build a tree swing, cut the seat, round the edges and paint with an enamel coating. Attach chains to the tree branch, measure and cut the rope, and attach the rope to the chains. Tie the seat to the ropes.
- Cut the seat
Select a dense hardwood board, such a yellow pine or oak, that measures 2 feet by 8 feet. Use a miter saw to cut a 20-inch length from the board.
- Round the edges
Use a quart-size paint can as a template. Place the can on top of the board at the corner. Use a pencil to trace a rounded edge. Repeat this for all four corners. Use a jigsaw to cut the corners off.
- Sand the edges
Use sandpaper or a rotary sander to smooth the edges of the board.
- Drill holes in the ends
Use a 5/8-inch drill bit to drill a hole 1 inch in from the edge of the board. Measure to ensure it's centered. Repeat at the other end.
- Paint the seat
Use a paint brush to apply three coats of outdoor enamel to all sides of the board. Use a cotton swab to paint the inside of both wholes.
- Select a tree branch
Select a healthy tree with sturdy branches. The tree should not be near obstructions. Choose a branch a minimum 8 inches in diameter no more than 15 feet from the ground.
- Attach the chains
Cut two lengths of sturdy chain so that they go around the target branch. Attach the chains 20 inches apart using anchor shackles. The inside chain should be at least 3 feet from the trunk.
- Attach the rope
Measure the height from the branch to the ground, and add 2.5 feet. Cut two pieces of a 5/8-inch braided polypropylene rope to this measurement. Use a figure-eight follow through knot to tie the end of the rope to each of the anchor shackles. Use a lighter to melt the ends of the rope hanging near the ground.
- Attach the seat
Thread the rope through the holes in the seat, and then thread the ends through 5/8-inch fender washers. Tie a double knot to secure the seat 2 feet from the ground. Use a tape measure to ensure the seat is level.
- Finish the swing
Trim excess rope from under the seat, leaving 2 inches hanging under the knot.