Any tips on ways to fix a cracked 4RT rear fender?

I've dealt with partial cracks by "stitching" across it with small zip ties. Drill a small hole at end of crack to stop it from spreading further. Then drill series of holes on both sides of the crack spaced about 1/4" away from the crack, and about 1/2" from each other.

Here is how I fixed my rear fender which I broke completely in half. I used a hacksaw blade about 16" long as a "backbone" underneath the fender, and riveted it in about 8 equally spaced spots. I also used 2 short segments of hacksaw blade (about 4" long) mounted underneath the fender, but running along the side edges. It has been holding up well so far. The hacksaw blade is made of flexible "springy" steel, so it bends together with the fender. As a finishing touch I added a strip of red duct tape to cover the blade. You still see the rivet heads on top of the fender, but they just add a little special "character".

i personaly would buy a new one but a friend of mine used a red golf tea a soldering iron and a grinder he filled the crack on both sides with the golf tea melting it with the soldering iron and then once he had solderd it all he used a grinder to smoth it off you cold not see the crack was even there after he had finished it.