DIY kneepads

Hey everybody. I was looking at leg guards online and was thinking of getting some 661 leg and shin protectors. But I am 14 and 6 foot 1 and I might have a growth spurt any minute now. I really do not want to spend 40 bucks on pads then get to big for them. So I was thinking of making my own pads. I probably would use a 1/2 inch dense foam(maybe pipe insulator) for padding and PVC sewer pipe(I would look like a stormtrooper)cut into strips for hardness protection, then secure it with velcro. Has anybody built their own before? Does anybody have any tips?

do it and tell us/show us how it works!!