Let me begin by stating that I don't have a problem with using a false bottom in the mash tun. I used one successfully for many years when I began brewing with all-grain. In fact, I would probably still be using one now if I hadn't gone from five gallon to 10 gallon batches. When I switched to larger brews I converted a Sanke keg to use for my mash tun. When I did this, rather then purchase an expensive false bottom to fit, I decided to take the easy and cheap way out by modifying a length of plumbing supply line into a mash grain filter. Here, I want to show how to circumvent the need for a perforated false bottom.
In the first example, I use a short length of stainless steel braided hose attached to a plastic spigot in a 5 gallon bucket for a simple solution for partial mash brewing procedures. Go here for the video example. In the second example I have a longer length of s.s. hose connected to a copper pick-up tube that is in turn connected to a ball valve for use in a larger metal mash tun that can come in direct contact with your heat source.
In either case it is necessary to separate the exterior s.s. braided hose from its inner rubber component. There are a couple ways to achieve this and the pictures are examples of both.
For the partial mash example, I cut the threaded nut off of one end off of a 12" length of water supply line. Then, using a sharp pointed tool (in my case a scratch awl) perforate the inner rubber hose around the entire circumference near the other end of the hose near the 1/2" threaded nut. Be careful not to molest the braided steel, you can see the black rubber hose underneath between the braids. Once you have thoroughly perforated the inner hose, pull it firmly from the cut off end until it separates and slides out. Now you have a s.s. braided hose with a 1/2" nut on one end. Now, slip about an inch of the cut off end through a one inch length of 1/2" copper pipe and hammer the copper pipe until it crimps the end of the hose. You can then thread the s.s. hose onto an adapter that is attached to the spigot. The spigot is attached to your bucket (mash tun) and your ready to mash. (See images above for reference)
For the converted Sanke keg mash tun or other large metal mash tun you can use a longer section of supply line. I have a three foot section of which I cut off both threaded end and then pulled the inner rubber hose out. I crimped one end with a length of copper pipe. The other end is attached to a length of soft copper tubing using a hose clamp. The tubing is in turn connected with sleeve and ferrel nut to a metal ball valve. I hope the pictures help to explain what is turning out to be a lengthy and difficult explanation. Comment if you have any questions.