100W / 500W / 1000W / 6000W: Pick the Right One in One Table

100W / 500W / 1000W / 6000W: Pick the Right One in One Table

Two experienced buyers spent forty minutes arguing about laser power at our booth last month. Both were right. Both were also choosing from the wrong column - and one of them nearly spent $52,000 more than he needed to.

Round 1: "Power is speed." Ralf's corner

Ralf opened with the only slide he had: a stopwatch. His wire-wheel crew cleans 1.4 m² per man-hour. A rented 500W demo unit did 9.8 m²/h. A borrowed 1000W did 19.4 m²/h. Same plate, same rust, same operator.

"You want to tell me power doesn't matter? I just doubled my throughput by plugging in a bigger box. That's not an opinion, that's a number."

He is not wrong. Clean rate scales close to linearly with average power up to about 1000W, then flattens as the beam gets wider than the part and handling starts to dominate. Every honest spec sheet shows this, including ours:

Note the last row. 6000W does not clean 6× faster than 1000W - it cleans 2.5× faster, because it is a different machine class limited by fixturing, not by photons. More on that in Round 3.

Round 2: "Power is heat." Yusuf's corner

Yusuf did not argue with the stopwatch. He put a 1.2 mm cold-rolled panel on the table, ran the 1000W at full width, and let it dwell for one second in the same spot.

"Look at that. Blue, then gold, then a dish. You just added 0.4 mm of filler and an hour of straightening to a part that was already finished. My customer charges $60 an hour for that panel. Your throughput number just became a rework number."

Also correct. Pulsed fibre lasers remove rust by ablation - nanosecond pulses dump energy into the oxide layer faster than heat can conduct into the steel. But "faster than conduction" has a limit, and the limit is a function of power density and dwell time, not of the number on the front panel.

So both men are right, which is the useless kind of conclusion. The useful version is this: Ralf's stopwatch measures the wrong surface. He timed 8 mm plate. Yusuf tested 1.2 mm panel. They were never in the same argument.

Round 3: "6000W is just a bigger 500W." Both wrong

This is where the conversation got expensive. Ralf said if 1000W is good, 6000W must be six times better. Yusuf said 6000W is a marketing number. Neither had looked at the source type column in Table 1.

6000W in this class is almost always continuous wave, not pulsed. That single difference changes the delivery, the safety class, the floor plan and the labour model.

That last row is the one nobody puts in the brochure. A 6000W CW cell carries about $18,500 a year in amortisation and consumables before it cleans a single square metre. It needs an enormous, boring, repeatable workload to pay that back - which is exactly what shipyards and structural fabricators have, and exactly what a job shop does not.

Round 4: The number neither of them was looking at

Here is the question that ends the argument in ninety seconds: how many square metres do you clean in a year?

Not per hour. Not per shift. Per year. Because every machine on this list has a fixed cost that gets divided by that number, and a labour rate that does not care how big the machine is.

Read it down a column and the argument dissolves. At 2,000 m² a year the 6000W costs 2.3× more per square metre than a 500W - not because it is worse, but because $18,500 of annual fixed cost divided by 2,000 is $9.25 that no amount of speed can recover. At 60,000 m² a year the 500W cannot physically get there, and the 6000W wins by default.

Round 5: Score the claims

The verdict: match the model to your binding constraint

There is no "best power". There is only the smallest machine that clears your annual area without breaking your part. Work out which of the three constraints binds first, then read the row.

Notice the pattern in the bottom three rows. The small machines are not bought to save money per square metre - at 400 m² a year the 100W costs nearly $12/m², which is worse than a wire wheel on paper. They are bought because nothing else fits through the opening, or because the part cannot take the heat. Access and gentleness are legitimate reasons to pay more per square metre. Speed is not.

Three questions, five minutes, no salesman

One. Take last year's jobs and add up the surface area you actually cleaned - length × width × faces you really clean. Divide by 46 weeks. That is your weekly area. Multiply back by 46 and you have the only number that matters.
Two. Find your thinnest part that needs cleaning. If it is under 2 mm, cap yourself at 500W regardless of what Table 4 says about cost, because Table 2 outranks Table 4.
Three. Ask who holds the head. If the answer is "a man standing on a ladder", cross out every CW machine on the list. Those need a robot and a cell, not an operator.

We build 100W through 2000W pulsed units and integrate CW cells up to 6000W, so we have no reason to push you up the ladder. Send us three part photos, your thinnest material and your annual cleaning area, and we will send back Table 4 filled in with your numbers - including the row where we tell you the machine you asked about is the wrong one.

Laser power selection500W vs 1000WPulsed vs CWCost per m²Laser cleaning