When setting out to build a slider, there are a few important points to consider. The most important thing to remember about building a slider is to make it safe. I know of a few slider falls that resulted in trips to the hospital. Don't have anything sticking out or in your way, or you will hit it sooner or later. A good slide rail must be long enough to get a good slide. Anything less than 20 feet long is too short. Thirty feet or more of riding length is ideal. It also must be smooth. Three-inch round PVC pipe is the best stuff to use as the riding surface. Stability is key as well. If the slider gives too much or is shaky it won't work.
Building a slider is not an exact science. Each one I have built has been different that the one before it. The best design is the floating purple one you see used at the pro tour. It has two side-by-side 3-inch PVC pipes 40 feet long as the sliding surface. It is about 2.5 feet high, and the ends curve down into the water for safety. The whole thing comes apart in two sections and can be set up by two people.
Where you are going to use it as well as how you plan on storing and moving it will dictate how you build it. I've never had any problems finding a good place to set my sliders up. I'm sure you will encounter someone who won't like it no matter where you set up your slider. If you are planning on setting your slider up in a shallow area of a lake and you don't plan on moving it much, it won't need to be a floating type. If it's going to be in deep water or if you will have to move it often, then a floating type will be best. The non-floater-type supports should be made out of metal or wood and resemble large camera tripods. The floating-type supports work best if they are shaped like pyramids so the top is narrow near the rail and wide at the bottom. There should be at least one major support for every 10 feet of slider length. Keep in mind that water levels of most bodies of water will fluctuate for many reasons, so plan accordingly.
Steps to Building
1) Figure out where you are going to set it up to ride it. If the water is over 8 feet deep or if the slider must be moved often, it should be a floating type.
2) Figure out if you have any friends who are crafty with metal or wood or if you have any building materials. By knowing this stuff ahead of time, you may be able to recruit some good help or save money on materials.
3) Draw some plans. Keep in mind the type of tools you have available and how much time and money you want to spend on the project.
4) Make a shopping list. At the top of your list should be four 20-foot lengths of 3-inch PVC pipe. The other materials will depend of the type you are going to build.
5) Go shopping. Be ready to spend some cash. Unless you live next to a salvage yard, you will have to purchase most of your materials. You can get your PVC pipe at a local irrigation supply dealer. Remember that you will have to cut off the female end of the pipes so that you won't have a nasty bump in the middle of the slider where you butt the pieces. Remember that you will need 80 feet of pipe (40 feet and 40 feet side by side). It may be a little more difficult to find Styrofoam blocks the size you need. A dock place could probably tell you where to get it.
6) Find the best place to work. A large flat area next to the lake would be ideal.
7) Get building. Work from bottom up. First, build the floats or leg supports and go up from there.
8) Get the slider to the lake. Always make sure the slider is completely together before you put it into the water. It's very difficult to work when you are leaning over the side of the boat or swimming in the water. TThe more people you have to help, the easier it will be to set up.
9) Anchor it well. You don't want your slider to tip over or drift away. Concrete blocks work great as anchors and stabilizers: three blocks per end for the floater and a couple per leg on a bottom resting type. Poly rope works great as anchor line.
10) Do some test runs in the boat. If you have a nice size wake and you drive right next to it, the slider should not tip over or float away.
11) Ride it. Don't try to slide the whole length the first time. Ollie up to the far end as you ride by. Start earlier each time until you are sliding the whole length.