The most common question we get is what rate the laser achieves. The plain answer is that a rate quoted without the job details is close to meaningless, and understanding why will save you a lot of money at tender stage.
The removal rate is not the site rate
Machine literature quotes removal under ideal conditions. Flat plate, bench height, one known coating, an operator standing comfortably, no interruptions. Real jobs have none of that.
On site the same head might spend half its time repositioning, waiting on access, working overhead at arm’s length, or moving around obstructions. The beam is doing the same work per second either way. The square metres per shift can be well below what the brochure implies, and that is not a fault in the equipment.
When you are comparing quotes, ask what the assumed access and setup is, not what the machine can do in a shed.
Coating type is the biggest single variable
Light surface rust and mill scale come off quickly. A single thin topcoat comes off quickly. A full three or four coat protective system takes several times longer, and the zinc rich primer at the bottom is usually the slowest part of the lot because zinc reflects rather than absorbs.
Thickness compounds it. Thicker coatings take disproportionately longer, because the process removes material in passes and each pass has to be complete before the next does any good.
This is why the useful question at quoting stage is what the coating system is and how many microns, not how many square metres. Two jobs of identical area can differ enormously in the time they take.
How clean does it actually need to be
A lot of money gets spent removing coating that did not need removing.
If the intent is to recoat over a sound primer, stripping to bare metal is wasted time. If the intent is inspection of a weld, you need a small area properly clean rather than a whole member. If a surface standard is specified, that standard determines the time, and moving from a good commercial clean to a near white finish costs disproportionately more for the last part.
Define the end state precisely. It is the cheapest decision on the job.
Substrate and geometry
Flat, accessible steel is the best case. Complex sections, back to back angles, tight corners and congested pipework slow everything down because the beam needs line of sight at a workable angle and distance.
Thin sections need lower energy to avoid heat input, which means more passes. Non ferrous substrates behave differently again and often need a completely different parameter set.
Setup, safety and the parts nobody counts
This is a Class 4 laser process. The controlled zone has to be established, screened and maintained. Everyone inside it needs correct eyewear for the wavelength. Fume extraction has to be set up at the head and the filtration managed.
On a live site that setup and pack down happens every shift, sometimes more than once if the work moves. On a short duration job it can be a meaningful share of the total hours, which is why very small isolated areas often price badly per square metre.
Batching small areas into one visit is usually the sensible answer.
Where the economics work
The laser rarely wins on removal speed alone. It wins on what it removes from the rest of the job. No containment structure. No abrasive delivered or recovered. No spent media to classify and dispose of. No clean down before coating. No shutting the area to everyone else while you work.
On a hazardous coating with an expensive disposal path, the waste saving alone can outweigh a slower removal rate. On a live plant that cannot be shut down, the ability to work without containment is the entire argument.
Judge it on the total cost of getting the surface ready to coat, including everything you would otherwise have to build, move and take away.
How to brief it properly
Tell whoever is quoting the coating system and its thickness, the surface standard required, the area and its geometry, the access, whether the site stays live, and whether the coating is hazardous. With those six things a sensible number is possible. Without them anyone quoting is guessing, and the guess protects them, not you.
Related reading: laser cleaning or abrasive blasting and laser paint removal on structural steel.
Talk it through
Our laser cleaning, rust and paint removal page covers what we run and where we work. Ring 02 7912 3054 and describe the job. We will tell you straight whether the laser is right for it.
Perfect Remediation and Refurbishment acknowledges the Aboriginal and Torres Strait Islander people as Traditional Custodians of the country on which we live and work. We pay our respects to the Traditional Custodians and Elders past, present and future, and honour their connection to the land and ongoing contribution to society.