A new excavator bucket starts losing metal the first day it digs. It never stops. The cutting edge rounds off, the side plates thin out, and the heel wears through where it drags. Hard-facing puts a harder alloy on those surfaces before the base metal goes, and when the ground is abrasive it’s one of the cheapest ways to keep a bucket in service. When the ground isn’t abrasive, it’s money you didn’t need to spend.
We hard-face buckets at the machine for contractors and rental fleets out of our Livermore shop, and we turn down plenty of buckets that don’t need it. Usually, it comes down to the dirt.
Abrasion decides whether hard-facing pays
Hard-facing is welding a wear-resistant alloy, or a harder plate, onto the parts of a machine that grind against the ground: bucket edges, teeth, side plates, dozer blades, moldboards. It protects against wear. It doesn’t make a bucket stronger.
Lincoln Electric’s alloy specialist put it bluntly to Construction Equipment magazine: “Unless you have abrasion as one of the factors for a part wearing away, you shouldn’t be using hard facing product.” Metal against dirt, sand or gravel, with some impact mixed in, is the classic case. A bucket that fails by cracking at the welds or bending has a different problem. An alloy coating won’t touch it.
How much longer does a hard-faced bucket last?
Longer than most people expect. In the same article, Lincoln put the typical gain at four to 10 times more wear life, depending on the soil. Caterpillar’s wear parts specialist framed it as an investment: spend 10 or 20 percent of the part’s value on an overlay and get three to five times the life, as long as the digging doesn’t chip it off.
That math is why fleets do it. A bucket rebuild costs real money and takes the machine out of service. If a few hours of hard-facing pushes the next rebuild out by a season or more, it pays for itself. We handle this as ongoing work for a national equipment rental fleet across Bay Area job sites, timed so buckets get done before the base metal is gone, not after.
The pattern should match the ground you dig
Hard-facing on a bucket usually goes on as a pattern of beads rather than a solid coat. The gaps matter. They trap dirt, so the dirt you’re digging wears against packed dirt instead of steel.
- Waffle or diamond are the two most common bucket patterns. Neither beats the other, but the rule of thumb is a gap of 1.5 to 1.75 inches. Go to 3 or 4 inches to save wire and the pattern stops trapping anything.
- In rocky ground, beads run parallel to the direction the bucket travels, so rock rides along them.
- In sand and dirt, they run across the direction of travel to hold material between them.
- Mixed ground gets a crosshatch or herringbone.
What does the machine dig most of the time? Tell us. Clay, decomposed granite, road base and river rock all wear a bucket differently, and the pattern should follow the job it’s actually doing.
Two layers, laid on cold
Most bad hard-facing comes from habit. The first pass mixes with the softer parent steel underneath, which dilutes the alloy, so a second layer is what gets you the full hardness. Running too hot flattens the beads, and flat or concave beads don’t trap dirt. You want them convex, applied as cold as the process allows.
More isn’t better, though. Stack too many layers of chrome carbide and the beads underneath get brittle and crack. And when a worn edge has to be built back up before it’s hard-faced, the buildup should be a proper buildup alloy, tougher than a mild steel rod like 7018, so there’s something solid under the hard layer to take the shock.
Wear plate is the other option
Some surfaces are better served by welding on a plate of abrasion-resistant steel, AR400 or AR500, than by laying alloy beads. Wear plate suits large flat areas like bucket floors, liners, chutes and truck beds. The filler matters here. Plate gets welded with a ductile filler on purpose, because a hard weld on a wear plate cracks under impact. We handle wear plate welding and bucket repair on the same visit when a bucket needs both.
Rebuild first when the bucket’s too far gone
Hard-facing protects metal that’s still there. Once the cutting edge or side plates have worn thin, the bucket needs a rebuild before anything else: new edge or plate material welded in, cracks repaired, then the hard-facing laid over the fresh steel. The same is true of the pin bores. A bucket that’s been working long enough to wear its edges has usually worn its bores too, and line boring the worn pins and bores in the same visit is cheaper than bringing the rig out twice.
Cracks are their own repair. If there’s a crack at a weld seam or in a side plate, our welding repair work comes first, because hard-facing over a crack hides it without stopping it.
When hard-facing isn’t worth it
Skip it when abrasion isn’t what’s killing the bucket, when the bucket is close enough to retirement that the added life won’t be used, or when the machine digs so little that the edge will outlast the job anyway. Brand new buckets are a judgment call. In rocky, abrasive ground it can make sense to hard-face a bucket right out of the box.
Batch the work when you can. We work to a 4-hour industrial minimum of $600, which covers a full crew and an equipped rig on site. Three buckets in one yard on one visit is a far better use of that time than three separate calls. Small attachments that can travel sometimes come out better on the shop bench, and mobile welding or the shop covers how to decide.
Get a bucket looked at
Send us the machine, the bucket size, what it digs, where it’s parked, and a photo of the edge and side plates. We’ll tell you whether it needs a rebuild, hard-facing, wear plate or nothing yet. Nothing yet is a real answer. HRT Mobile Welding is a C-60 licensed welding contractor, license #1132921 (you can check it with the CSLB), with AWS certified welding specialists and full insurance.
Call (925) 518-6694. Or request a quote online. Our two rigs run out of 3555c First St, Livermore, CA 94551 and cover Hayward, Oakland, Fremont, Tracy and the rest of our East Bay service area.