Materials needed:

PVC pipe of various sizes (Home Depot sells 10 ft. length for 70 cents). 
Duct or Masking tape
One 2" Lag screw  per perch (I think that's what they're called; they have threads on both ends) or threadall of desired size and length.
Washers  (must be wider than the outside diameter of the PVC pipe and the appropriate size for your cage wire)
Wing nuts  (make sure it's the appropriate size for the lag screw or threadall)
1 bag all purpose sand
1 bag cement
1 tin can or something to hold the molds.

Now comes the fun part:
1.) Cut the PVC pipe to whatever length perches you want.  If you're making more than one, cut them all at once.  Power tools make it much easier.  I usually make mine 6" long.
2.) Now cut each piece of PVC pipe down the center, making a seam.  This is not an easy task, but the cut doesn't need to be straight, and my seams usually end up jagged. I have used wire cutters, scissors, garden shears. A "Dremel" tool with a cutting disk can make  these cuts a little easier.
3.) Take the duct or masking tape and tape the bottom and the seam of each piece of PVC pipe, so that when you add the cement mixture, it won't leak out.
4.) Stand all of your ready to fill PVC molds into a can, open end up. I have a piece of 2x4 with holes pre-drilled to hold the molds. The 2x4 I use is about 18" long and holds about 20 molds.  The holes were drilled1/2 way through the 2x4 using a  wood bit just a little larger than the PVC. They are spaced about 1" apart. To use the threadall for the longer perches drill a hole the diameter of the threadall all the way through the 2x4. This is so you can attach the washers and wing nuts to both ends of the long perches, to attach to 2 sides in the cage. The perches will be heavy, so anything longer than 6 inches will have to be supported on both ends.
5.) Mix 3 part sand to 1 part cement and add enough water to make it kind of smooth and pour-able.  MIX WELL, and add more water as needed.
6.) Pour the mixture into the PVC molds (a little overflow is better than not filling completely, because some of the water in the mixture will rise to the top)
7.) Place a washer, followed by a wing nut, onto a lag screw, and place it into the center of the cement mixture.  The washer will keep the screw from falling into the cement.  Don't worry about any dribbles down the side of the molds, this is mostly water.
8.) Let the cement set for several days,... the longer the better.  If you become over anxious, your perches will fall apart when you take them out of the mold.  I learned this the hard way.
9.) Once the cement has set, remove tape and spread the PVC pipe.  Take a pair of pliers and pull the perch out of the mold by grabbing onto the screw, or in most cases you can push the perch through the mold once loosened.
10.)The perch will be smooth on the surface.  I roughen them up by lightly sanding.  If you don't have sand paper, you can use a file, emery board, or whatever.
11.)Attach the perch to the inside of the cage, one washer up against the cement, attach other washer on the outside, through the cage bars, and secure with the wing nut.
That's it!  I hope I didn't leave anything out.    mixture of gravel and cement (or mortar). I call my perches cement, even though technically they're mortar. (Most people don't know what mortar is). I use a ratio of 3 parts sand to 1 part cement, but if your hubby would feel better, let him go 2 to 1 ratio. When I first started making these, I used straight cement (no sand) and water. It took longer to set up and the finished product was too smooth, even after sanding. The reason these perches take so long to set up, is because there is no air flow inside the mold, and the mixture is surrounded by a non-porous surface. I let mine set up for AT LEAST 1 week. If you don't do this, your perches will fall apart when you remove them from the molds. These perches, ONCE hard, are not toxic.