When i bought my front loader, it had been cracked, forced back together, and they did some shabby patch work on the sides of the arms, to make it sell-able.
I cut the 3/8"x4" and 2ft long patches off the sides, ground it smooth and welded two flatbars of 3/8"x2" over the full length, top and bottom, of the loader arms. That increased the bend resistance by 71% in this particular case.
People often think they need heavy patches on the side: However when a body is strained with a bend load, there is compression in the lower part, and stretching in the upper part. In the middle (the neutral axis) there is a point where no force is.
With some 3 ft long, 1/4" plates, as wide as the dipper is, cut into a point (to get an even overflow of forces from the reinforced area into the non reinforced area) you could beef that dipper up, way over its original strength, with just minor weight gains: just add some metal on top and bottom, where the greatest bend forces occur.
I guess the dipper is nothing fancy, just A572 grade 50 steel (or St.52.3 in Europe) which would require a patch plate of comparable yield strength (which is just a wee bit over ordinary household steel) These carbon steels can be welded with common welding rod and mig wire.