This is my first instructable and will try and give credit to everyone who gave me help with this project. This is a modification to the Hanging Basket Column project by mtairymd. I built three planter boxes following his design but then I wanted to have a try at an octagon planter box and use boards from pallets. I apologize if some of my measurements are a little off, I had to make minor adjustments as I built the boxes.

Step 1: Tools/Materials

Tools:

Table Saw
Planer
Drill
Belt Sander
Tape Measure
Brad nailer
Pencil

Materials:

4x4 x 6’ (x1)
Pallet Wood
End Cap (x1)
Hangers/Screws (x2)
3/4 and 1 inch brads

Step 2: Planter Box

I broke down about 6 pallets for this project only using the top deck boards. The bottom ones were too dirty or damaged. I used a reciprocating saw to cut the nails then went over each board to remove the nail heads.

I ran the boards through my planer and took them down to 3/8 inch. I do not have a jointer so I turned the boards on end and ran them through the planer to get a straight edge on one side.

I set the table saw to cut the boards at 3 inches wide. I wanted the planter box to be 18 x 18.

Step 3: Planter Box-Frame

When I determined size of the planter I used a Segmented Turning calculator I had used when I built a column for another project. This is where I made a minor mistake, when I calculated the outside diameter of the planter box, I forgot to add in the outside board width. It was a minor problem that I will point out later but a good lesson to think all the way through a project. Because it was difficult to keep everything squared as I assembled I had to do a bit of trimming so the joints were tight. These are the measurements I came up with for the boards.

Item Quantity Part Name Description

1. 16 Platform/sides 3 x 7 1/2 Cut ends at 22.5 degrees

2. 4 Bottom deck 3 x 19 1/4 (I trimmed after installation

3 Bottom deck 3 x 15 (I trimmed after installation)

3. 24 Sides of box 3 x 16 5/8

4. 8 Outer trim 3 x 8 1/2 Cut ends at 22.5 degrees (I trimmed them if they were a bit long)

5. 8 Top trim 3 x 8 1/2 Cut at 22.5 degrees (I had to trim two angles because I was not square)

6. 16 Corner blocks 1 1/2 x 3 1/2 Cut at 45 degrees

Some of the pallet boards were damaged when I pulled the nails but when I cut the angles and cut to size I was able to cut most of the damage away with very little waste. Item 6, the corner blocks I cut from a 12 inch piece of 2 x 6. I made three cuts at 45 degrees, the first cut took off one corner then flipped the board over and cut off the opposite corner. I then reset the table saw and split this down the middle. The measurement does not need to be exact, these pieces are to hold the corners in place but it also helped with the deck and trim pieces.

To cut the platform boards set the table saw at 22.5 degrees. I took five of the pallet boards and cut one end at 22.5 degrees. On the miter guage set up a stop at 7 1/2 inches, cut the piece, flip the board and cut the next piece. I was able to use the angle cut from the first cut for the next platform board.

When I assembled the frame I created a simple jig, (see picture) I screwed two four inch pieces of 1 x 4 to my table at 45 degrees. I left a gap between them so that one of the platform boards (item 1) would fit between them. Then place a corner block and a second platform board in this jig. I used a scrap board to push on the outside of the platform board. This allowed me to get everything lined up and it kept the boards tight. I secured the boards with 1 inch brads. Pick the piece up and repeat with the next corner until all 8 corners are done.

Because the corner pieces are shorter then the platform boards make sure all the corner blocks line up with the same edge of the platform boards.

Step 4: Assemble the Frame

Bottom Deck.

Pick one of the frames to be the bottom of the planter box. I did not try to precut the boards with all the angles, it was easier to trim off the excess and ended up with nicer looking edges after they were trimmed and a bit of sanding.

Cut 2 boards at 45 degrees and secure to the bottom frame.

NOTE: Pay attention that the frame stays squared. The frame had twisted a little on me and it affected the final angles when attaching the Outer trim and Top trim.

I used 1 inch brands and attached the pallet boards to the corner blocks. When I had 2 boards attached I trimmed off the excess on the table saw. Then attach the next boards. Trim as you proceed. Because my frame was not squared I had to add a small piece to cover the last part of the frame.

Sides.

I attached temporary boards on 3 sides to keep the spacing between the bottom deck and the top ring. Cut 8 planter box side boards at 45 degrees on the long edge. Start at one corner of each frame, line the cut edge so it is straight with the edge and secure. When I was nailing into the corner blocks I used 1 inch brads and when I nailed into the frame between blocks I used 3/4 inch brads so they did not poke through the inside board. The third board will overhang the next corner, this made a perfect stop when attaching the first board on the next side.

Remove the temporary boards as you move around the box. After putting on 3 sides I trimmed off the excess lengths on the table saw and used a belt sander to remove what was left.

I attached 3 more sides, trimmed and sanded and then put on the last two sides.

Step 5: Outer Trim and Top Trim

Because I did not calculate the outer diameter of the planter box correctly it threw off my measurements on the trim pieces. In the end, the pieces were a little long but this worked to my advantage when I had to do some trimming and adjusting an angle.

Outer Trim.

I clamped three of the Outer trim boards to the box. Because the box was not square and the pieces a little long I had to trim the boards so that the corners lined up properly. I used 1 inch brads to attach the trim pieces with the corner blocks.

I had to change one angle on the last board by a degree so that everything lined up properly.

Top Trim.

Lay out the Top Trim on top of the planter box. I used painter tape to hold the pieces in place until everything was lined up properly. Because I cut the top trim the same length as the outer trim they lined up evenly. I think if I had cut it 1/8 inch longer the top trim would have overhung the outer trim and it would have looked nicer. I attached the top trim with 1 inch brads.

Step 6: Column

I had to make one change to the Hanging Basket Column project by mtairymd. The base is 13 x 13 with the corners trimmed so that is will fit inside the planter box. I ran the post through the planer to remove any noticeable damage to the post and ended up with a 3 x 3 post.

The base was attached to the post with a 2 inch lag bolt and 4 two inch wood screws. I then mounted an endcap and hangers on the post.

Step 7: Final Comments

I did not stain or paint the column and planter box, I built two of them for a friend who was very happy with the result, they had not decided it they were going to paint or stain it the last time I talked to them. Even though I used wood from pallets instead of the thicker boards mtairymd used in his project the box seems very stable.

I hope you find this instructable interesting.