Sail Types
The fundamental nature of the PDRacer is to allow you to use any type of sail rig you want.
Effective sails can be made with polytarp and other really cheap materials, which are very quick to build (like 1 hour from raw materials to finished rig for some types of sails), you should experiment with several sail types to discover which ones you like for your situation.
The PDRacer sails well with 60-80 sqft of sail.
If you were building boats for kids, a sail as small as 40 sqft should work fine for them.
How Sails Work:
Basically, they are like airplane wings.
They have a curved shape built into them, and as the air flows around them, they pull the boat in the water.
A good essay on the subject is at
North Sails
Another explanation, but explains airplane wings which are similar HowStuffWorks.com
Sail Fabric / Materials:
The material you make your sail from is very important.
You need something that won't stretch, so it will retain that all important shape which provides lift.
Polytarp - (used for covering cars, boats etc) is the most popular material to make sails from, because it is so CHEAP, you can usually buy a single large tarp for about $10 at Home Depot.
The most common color is blue, and it is usually the lighter weight tarp.
You can mail order other colors like white which are a lot heavier grade (and longer lasting), plus a complete kit including everything you need for a tarp sail, from Dave Gray at PolySail.com, who is also a puddle ducker, he built hull #100.
The great thing about it is the cheapness, and with 1 hour and a roll of duct tape, you can have a finished sail.
The bad part, is that if you abuse it by storing it out in the sun, it breaks down quickly (like leave the blue type out in the sun for 6 months, and it will start to fall apart).
If you are carefull with it, store it inside, you can make a polytarp sail last for a several seasons or more.
Best use is to make a sail from polytarp and try it out for a while, and later make a sail from Tyvek or Dacron.
Or heck, since it is so quick & cheap, just make another tarp sail when your first one wears out.
Tyvek (and Typar) - is a construction material used in houses to make the walls waterproof, also used for un-rippable envelopes.
Tyvek comes in much less variety of colors, mostly white with the Tyvek logo printed all over it.
It is a very durable and UV resistant material.
Bad part is that duct tape and glues don't seem to stick very well to it, yet when pulling the tape off it will pull free some of the fibers.
Also it is very noisy when you flog them.
You will want to sew your sail together with upostry thread, it feeds easily thru a common sewing machine a lot easier than Dacron.
The commonly available size is 36" wide x 150', and 9' wide x 150'.
The wide roll is nice, you can cut a sail from a single pice, but it is expensive enough that you will probably want to buy a roll with a couple of other local puddle duckers.
The good part is that after you make your sail, it will last a LOT longer than the polytarp one, possibly you will never need to get a Dacron sail.
Dacron is the most common "real" sail material, the best place to get it is at the Duckworks Boat Builder Supply.
You can also order custom sized sails from there.
Bad Materials - Ripstop nylon is good for spinnakers, but not for upwind sails because it stretches out quickly.
Canvas, bedsheets, natural fibers, nylon, visqueen, clear or black construction plastic, do NOT work very well because they stretch and loose their shape.
Sail Fabric / Materials: