Assemble the plumbing fittings for the front wall
Before you even begin cutting any wood, I highly suggest you put together all your pipe fittings. Doing this will ensure you have the right couplers in place and allow you to accurately determine the measurements for the support wall and base. This will set the course for the rest of the build.
Assemble the plumbing fittings for the shelves
Assemble the pipes for the two shelves on the backside of the clothing rack. As compared to the large configuration on the front side, these each consist of only a couple flanges, elbows, 12-inch pipes, and a single 36-inch pipe.
Cut the plywood
Crosscut the 4×8 sheet of 3/4-in. plywood into two pieces: 72-in. for the support wall, and 23-1/2-in. for the base.
Stain and condition the wood
For a high-quality finish, it is best to stain the wood components before assembling them. Stain the base and support wall as well as all trim pieces and allow them to dry. You can cut the trim pieces after the 1x2s have been stained and do quick touch-ups on the ends after the unit is put together. By going in this order, you will save yourself from much more particular and stressful process.
Screw together the back and base
To make this process easier, I first glued and brad nailed the base and support wall pieces together and then install the screws. Doing it in this order secures the wood in place and prevents having to fumble with angles while securing the screws. Be sure to pre-drill pilot holes for your screws using a countersink bit. This will ensure your screws are buried flush to the surface and wood does not split open when installing screws.
Trim the plywood edges
To give the plywood a finished look and hide all the seams, I applied a trim all the around the unit. I prefer to cut as I go when I am installing the trim to ensure accurate measurements and tight joints. Start from the bottom of the unit, cutting and installing side base trim followed by the front and back trim. Then, work your way up to the side trim and end with the trim on the top of the wall.
Install casters
Make sure the placement and full rotation of your casters doesn’t get caught up on the trim around your base, I had to hold my particular casters in four inches from the base trim. I placed a block of wood under each caster to allow me to use longer bolts and give me enough wood to secure those bolts tightly.
Install flange support rails
Lay the configuration of pluming pipes and flanges (which you already put together before you started cutting wood) on the unit and center it where you want it to line up on the base and support wall. This will determine where the flanges will line up and where you should install the flange support rails to screw the flanges into.
Secure pipe configuration
Install the flanges through the rails in the support wall using 1-1/4-in. screws. Secure the bottom flanges to the base using 3/4″ screws. Use a speed square to make sure you have an accurate right angle at all your corners and from the side bar flanges to the support wall before screwing them down. It is very easy to pull out a pipe and lose that right angle.
Install the shelf pipes
Screw in flanges with support pipe for shelves on opposite side. Remember the wood rails on the front side will allow for 1-1/4-in. screws to install these.
Install the wood shelves
Cut the three wood shelves. One shelf for the bottom of the larger pipe configuration and two shelves for the other side.
Seal the unit
Seal all wood and any plywood pieces on the unit with a polyurethane or varnish. Use a quality brush and carefully cut in around the flanges.