Excavator buckets can fail due to corrosion or due to heavy usage that literally
wears away the steel or breaks the welds. This excavator bucket saw use in
a gravel pit, but given that a new rock bucket can cost in the tens of thousands
of dollars, repairing an existing rock bucket is always an option. The bottom
of the bucket has already been cut out and will have to be replaced with
hardened steel, on which the new tooth shanks will be welded. Abrasive resistant
steel (AR400) offers much better wear resistance than the mild steel some
stock buckets are fabricated from.
To the left you can see a new steel sheet formed over the bottom of the bucket
with the tooth shanks and teeth already installed. The bucket is formed by
first welding up the oversized sheet, and then trimming the edges, because
the the sides of the bucket are tapered rather than square. A hydraulic piston
was used to bend the steel sheet to conform to the curve of the bucket's
walls after the end of the sheet was welded in place. Mike is welding on
a wear plate or grouser bar above the cutting edge, which takes the most
abuse on the bucket. The tooth shanks are welded to the cutting edge, and
the teeth (technically caps) are mounted on the shanks with a pin. If you
can ship it or we can pick it up, contact Mike Dougan at 413-477-0225 for
a quote. In the video to the lower left, Mike is welding a grouser bar on
a rebuilt Caterpillar 325 excavator bucket.
The only original part left on this Caterpillar 235D excavator bucket to
the upper right is the small diamond area on the bucket ears, which attach
to the stick, or dipper. The bucket is heavily dressed with wear strips for
use in rock. Digging through ledge wears out a bucket in a hurry even if
you keep up with the maintenance of the tooth caps and the cutting edge.
Most buckets are equipped with removable wear bushings in th ears which are
easily replaced. The bushings are hardened steel and the pins are mild, so
that the pins take the damage if the bucket is abused. New bushings can be
replaced in the field with a through-hole Portapower 50 ton piston. In the
video to the right, Mike walks through the rebuild of a Cat excavator bucket
with new side walls, grouser bars, wear blocks, and builds up the shanks
with weld to extend their lives, as the poor man's option to replacing the
whole cutting edge and shanks
