An alternative to the DIY PVC cart - easy to make, doubles as a step for loading / unloading and folds for convenient transportation / storage. It doesn't get much easier than this.
Step 1: Folding Step Stool
Needing a kayak cart, I was looking for alternatives to measuring / cutting / gluing (cursing*&$#! / re-measuring / re-cutting / re-gluing) a PVC cart. In the process, I came across this folding step stool. (ranging in price from $10 - $15 online or local store)
Step 2: Axle
Cut a 3/8" threaded rod to 17" in length - grab a few nuts and washers along with a couple of 8" wheels.
Step 3: Drill
Drill out the center of the hinge with a 3/8" bit.
Step 4: Insert Axle
Slide the threaded rod through the hinge and center it.
Step 5: Lock in Axle
A washer on either side of the step, double nut to lock in place (it also gives proper spacing/clearance for the wheels).
Step 6: Add Wheels
A washer on either side of the wheel and another double nut set on the outside (end cap optional).
Step 7: Ready to Roll
Done - ready for use as a step to help load and unload.
Step 8: Fold
Collapses for convenient transportation and storage.
Step 9: Flipped to Position
Flipped into position.
Step 10: Add Padding
Your basic foam noodle padding - slits cut to slip over stool feet / edges. (foam held in place with Velcro cable ties found in any office supply store)