Couple of pointers to those thinking about this. Most plastic welding kits have a rheostat that will allow temp control on the iron. Different plastics, different temps or you risk making the plastic brittle. The reason he has to go to the lengths he is to reinforce is that he has very little penetration into the material. Just like metal welding the joint needs to be "V"d out to get penetration. Puting a spoon tip on helps with making a smooth joint and having a clean smooth tip helps a lot. A quick preheat with a heat gun can also help with getting good penetration. And finally that hot plastic causes serious burns if you get it stuck to your skin. Was welding a plastic water tank under a 5th wheel RV when I felt the need to push a sagging section back into place..... you will make no win choices very quickly.....
The real welding rods are easily available and having the right kind and size makes a difference.
But really with all the bonding agents available why bother. Try 2P 10 or one of the two part glues with the mixing nozzle. The glue used on ABS plumbing is quite aggressive and ugly yellow to boot. Prep, clean, glue.
