My team used the 1/4 inch clear polyurethane tubing from mcmaster. I constructed a welder out of these parts listed:
Materials:
-one 6-inch piece of KOP C-Channel(cut out notches on each side where the holes are lined up so that the belt can be taken out once it is welded)
-squirt bottle WITH WATER!
-Heat gun
-pair of nice channel locks
-piece of flat bar(used for rolling the belting to create smooth weld)
Process:
1: cut an access whole on each side of the c-channel so that each end of the belting can touch and be pulled out with ease(when it is connected).
2:Have one person hold each side of the belting slightly spaced apart while another uses the heat gun to start a slight melt on each side of the belting(person holding the belts might need some gloves if you have sensitive hands
)
3: As the belts start to look "melty", push them together and continue to heat to the point when the ends of the belt reach its melting point, then remove the heat.
4: Use channel locks to squeeze the belting smooth and squirt with water to cool it down so it can retain its shape.
5: Place belting on flat surface and roll it with the flatbar(works nicely if it's cold), I usually rolled in once forward, and once back.
6; Now, brag (graciously) about how successful a weld you have without spending 300-400$ on a belt welder
We were able to weld 30 belts in about 45 minutes(including a snack break). It might take a few tries to master, but the welds will turn out really nice, almost as if you bought a welder to do it for you.