This is a project inspired to a similar object seen in a furniture fair.
Despite the old-style of this coat rack, the folding gear is in my opinion quite cool.
When the rack is closed its dimensions are very compact, you can keep it in the umbrella stand, and you can open it when your guests arrive.
Step 1: Design and Material
To obtain four poles as legs I split two old wood bars in two pieces each.
I then found one sturdy wood block to use as central hinge.
Step 2: Hinge Design
The hinge design is the hardest part. The angle of the diagonal cuts will determine the width of the base when the coat rack is open. If you fail to determine this angle the rack will fail to hold up the coat, or it will be so wide to be awkward. Another parameter is the height of the hinge from the floor compared with the total height of the rack.
When I built my rack I made some test and I leaned the wood bars on the table to mark the angle on the hinge, now you can see a better calculation made for this instructable. In the drawing I showed different widths and different hinge heights, and you can also see the appearance of the rack in these cases. The first case is not feasible since the vertical line from a weight on the hook will fall out of the foot, but all the other cases are good, and in my opinion second and fourth are also nice. Third and fourth are probably more firm.
My rack is very near to the second case. You ccan also change total height and maintain the angle which I added near the hinge. This angle is between a vertical line and the open rod, and is the same angle you have to keep when you cut away a part of the hinge, as you see in the second drawing. The dimension marked as A is half width of the rods.
Step 3: The Hinge
You can use a band saw to cut slices from the block, as described in the drawing. The angle will determine the opening of the rack base.
Step 4: The Japanese Saw
Perhaps a better way, and certainly a more precise solution to cut the hinge is to use a Japanese saw.
Choose the method you prefer.
Step 5: The Coat Hooks
From every pole cut one hook, so to have four of them. Then refine each one rounding off one edge and cutting two grooves.
You can also paint pieces with a brown impregnating agent, the mordant, to make uniform appearance on all surfaces.
Step 6: Aging Treatment
Before painting the rods you can beat the new cut surfaces with an hammer and a metal brush, to create some irregularities to appear the same as on the uncut faces.
Then paint everything with mordant, one or more time if needed.
Step 7: Assembling
To assembly the hooks I tried both iron nails and wood dowels.
If you use nails pay attention to insert them exactly perpendicular to the surface, or the hooks will open wrong.
You can't see wood dowels in pictures, but they have a very nice appearing especially if they remain brighten than the rods.
Step 8: The Hinge
You must use special screws which have a pair of centimeters with no thread.
To determine the exact position of the screws make as first holes in the rods at the right height, then place poles in position on the hinge and mark the hole position with a nail. It's better to make narrow holes before screwing screws in the hinge, to avoid cracks.
To open the rack you must keep the hinge in one hand and force the rods making a clockwise rotation with the other hand.
Test the rack on a flat pavement to check its stability.
Step 9: Call for a Party
Finally you can call lot of friends for a party and test your new foldable coat rack!