It's easy to make this stunning spiral garden planter. Build it to any size you like by varying the component sizes and number of layers. I'll describe making the low planter shown in the photograph, for which I'm going to use just a few softwood pallets, glue, brads, and stainless steel screws.
I'm entering this in the Outdoors contest, so if you like it please consider voting - thanks
This is an almost identical build to my Spiral Table (in fact the video shows both), but I've separated them out into two Instructables to make the titles easier to search and understand.
Step 1: Break Pallets Down
For the size shown in the photo's and free plans, you can cut the rough components straight from standard size pallets, avoiding the hassle of pulling nails!
I'm using a plunge/track saw, but a circular saw, jigsaw, hand saw, etc. is fine. Just cut the boards up next to the bearers. You should end up with boards about 12-13" long, 2-3" wide, and 5/8-3/4" thick. You'll need sixty three of these.
You can see how my boards vary in thickness and width from the untidy stacks they formed - we'll tackle that next.
Step 2: Cut Layer Sides the Same Width
To get sixty boards the same width for the layer sides, I use my jointing sled at the table saw.
The sled has a fence that is parallel to the back side, and therefore runs true with the saw table fence.
I place each board in turn on the sled, up against the fence, lock it in place with the toggle clamp, then rip a small amount off the one edge by running the sled against the saw tables fence. This gives me a board with a clean and straight edge. Now repeat fifty nine times.
Next I put the clean, straight edge of the board against the sled fence, and rip the board to width. Again, repeat fifty nine times.
Now I have sixty layer sides, each with two clean, straight edges, parallel to each other.
Step 3: Cut Layer Sides the Same Length
Using the mitre saw, I cut one end square to the clean edges, and repeat for fifty nine more boards.
Next I set a stop on the mitre saw to give me the length I want, and then cut sixty boards to this length.
I also cut some extra boards for the base to length (layer side length minus width).
See how the stack is looking better.
Step 4: Thickness Layer Sides
You could now run all the boards through a thicknesser to get them the same thickness, but I used the table saw, since my thicknesser has broken down. This method worked very well in fact, and the stacks soon looked much better.
Find the thinnest board, and set the fence so that you can rip a hair off the first side. Go ahead and do that, and then using the same fence setting, run all the other boards through.
Now bring the fence a little closer to the blade, and run all the boards through, removing the final rough surface.
If you're aiming for a specific planter height, then you'll need to divide the base height by the number of layers you want, to find an exact thickness to finish the boards. For mine, this was 14mm.
Step 5: Set the Bottom Layer
Each layer is made up of four identical layer sides.
I laid them out on a piece of ply and then pinned battens around them tightly.
Apply glue to the mating surfaces, and place within the battens.
Finally add two battens on the inside to firmly keep the four sides in place.
Step 6: Add Layers
Now you can proceed to add each layer in turn, pinning them with brads as you go, to avoid the need for clamping.
Set each new layer in place, keeping all the layers centred, but rotating each layer such that you end up with the final layer in line with the first. (If you have four layers, then each one will need to be rotated 30º (90º ÷ 3). For 'n' layers, the angle is 90º ÷ (n-1).
(I just copied the offset and crossing points for each successive layer, rather than measuring angles and checking for concentricity.)
Step 7: Slap on a Finish
I finished mine with a black, water based preservative, which sinks in and covers well. It raises the grain a little, so for a fine finish you should lightly sand and apply a second coat.
Step 8: Glue Up a Base and Fit It
With the main spiral completed, you can rip the base pieces to width, and glue them up so that they are a little sloppy in the bottom of the spiral (that way they won't cause any problem when they get wet and swell a little in width).
When cured, the base can be fitted with a couple of long, stainless steel screws, driven in at an angle.