Name the deposit before you name the method
"Cutting oil" on a machine exterior is rarely one substance. On a lathe or machining centre that has run for a shift or two, you will find a poured or splashed film of neat oil on the way covers and chip conveyor, and a dried paste where the same oil has collected swarf. The paste matters. A film of neat oil lifts off easily; swarf-bound crust is a composite, half abrasive metal fines and half binder, and the crust must be broken before the oil carrier under it can do any work. That is why one job can need a hot, low-volume steam pass while the crusted section needs a wetter pass with a dwell before the wand moves on.
Two further deposits sit beside the cutting oil and are usually invisible in the enquiry. Way oil and slideway lubricant sit in the tracks and wipers, and they are the reason the boundary in the next section matters more than the cleaning parameters. Hydraulic bleed and airborne mist film coat the cabinet and the electrical enclosure above it, and a mist film spread over a wide area is a different quantity of work from one oil pour on one panel.
A buyer who cannot say which of these is on which surface, and roughly how old it is, cannot read a quotation as a method. The supplier is offering a machine, and a machine is not a method. Write the deposit list surface by surface first, then decide the mode and the pass for each line of that list.
The exclusion boundary is a hard limit, not a preference
Steam is hot water in quantity, and a machine tool is a collection of parts that must stay dry. Before anyone asks how long the cleaning takes, the buyer should write down what must not be wetted and what replaces the steam pass on those parts. On a machine tool exterior this list is long and specific: the way covers and the slideways behind them, the wiper seals at each end of a track, the ball screw and its guard where one is fitted, bearing and shaft ends, the terminal box and every cable gland, encoder and linear-scale housings, sensor connectors, pneumatic fittings, the reservoir filler necks and breather caps, servo and spindle vents, the fan on the electrical cabinet, and the nameplate and any instruction or safety labels.
The limit here is that a better machine does not shorten this list. It is the geometry of the equipment. What changes with the supplier is how well the machine supports the boundary: whether the operator has a lance long enough to work the panels without leaning over an open track, and whether the dry mode is genuinely dry at the nozzle, which is a supplier statement to be written down and not a guess from a model name.
Every excluded part needs an alternative written beside it: a wipe and a solvent-free cleaner for a panel face, a hand-applied degreaser with a cloth and no spray for the area around a gland, a brush and vacuum for a crusted guard edge. A quotation that removes steam from the excluded line and offers nothing else has not solved that line. It has moved the cost into the downtime column.
One more exclusion belongs to the shop's own history rather than to the machine: repainted or re-coated panels, and any vinyl decal on the guarding. Heat and dwell lift a coating that was never cured to the original specification, and no cleaning method restores an adhesion that was not there. Ask the maintenance department which panels have been painted since the machine arrived and mark them on the drawing as dry-clean only, with the option of a taped test patch and photographs before and after on a hidden corner.
Run-off is the limit that decides whether the shop can use the method at all
The oil does not disappear. It leaves the machine as an emulsion of water, oil and fine swarf, and that mixture has to go somewhere that the site already permits. This limit ends more steam projects in machine shops than any other, because the building around the machine was never designed for it. A machine standing on a sealed shop floor with a rainwater gully nearby is a completely different case from a machine standing beside a drain with an oil-water separator downstream, and the second case may still require permission.
Before the quotation, have the site confirm three things in writing: where the run-off is allowed to go, who signs that route, and how the captured swarf and the separated oil are removed afterwards. Then get the machine side answered: whether the supplier offers containment and recovery accessories, what they actually capture, and how much water the unit moves in an hour. That water figure is a specification row to ask for, not one to infer from a tank size; a tank is a holding volume and says nothing about an hourly rate.
Two consequences follow and both belong in the cost sheet rather than in a footnote. Time goes into laying containment and a collection route before the first pass and clearing it afterwards, so containment is a schedule item and not an accessory on the invoice. And the floor under the work needs a slip control for the whole period it stays wet.
Heat and dwell do the work; water volume is a cost and a risk
When a shop compares cleaning options, the instinct is to compare how much water each one throws at the part. For cutting-oil residue that comparison points the wrong way. The oil needs heat and a short dwell to loosen, and the abrasive in the crust needs time to be lifted rather than force to be driven into it. Excess water is not a cleaning agent; it is the substance that then has to be contained, drained and dried, and the substance that reaches the parts on the exclusion list.
This is where a dry-versus-wet capability earns its place on a machine-tool job: choose the mode per surface, not per machine. A large painted panel with a fresh oil film is a wetter pass; an oil film that has crept into a seam or a cast surface is a hot, low-volume pass with a dwell; a mist film on an enclosure is a dry pass and a cloth. A machine that only delivers one kind of output forces you to accept that one kind everywhere, including where you did not want it. The supplier's own product pages name the mode choice, and on the fixed-unit page for Fixed Steam Cleaning Machine PowerDe HW02 the cleaning mode row reads dry steam and wet steam, with a vacuum cleaner noted in the remarks column for the same unit.
Read that row honestly, though. A machine-tool duty has not been added to the published applications of that unit; the applications the page names are vehicle exterior work at fuelling stations and parking areas, work on internal surfaces of vehicles, and engine-compartment work. So do not transfer a claim from one industry to another. On a machine-tool enquiry, a mode row is a starting point for questions: at what point in the machine is temperature measured and at what point pressure is measured, and what figures belong to the exact machine being quoted.
Specification rows are not comparable across suppliers, and notation is part of the problem
Every cleaning supplier publishes a table. The rows in those tables do not mean the same thing from one supplier to the next, and buyers who compare two tables side by side end up comparing formatting. The point to hold on to: two tables become comparable only once each figure names where and under what condition it was measured. Ask, for each row, where and how it was measured, and on which machine.
This supplier's own records make the point. The specification table on the page for that unit, Fixed Steam Cleaning Machine PowerDe HW02, gives a steam temperature and a vapor pressure whose units and spelling the same family has used inconsistently elsewhere, and the model row carries a voltage inside the model name. That is not an argument against the machine; it is a reason to have the rows for the exact quoted unit confirmed in writing, with the measurement point named, before two quotations are called equivalent. The table on that page also lists heating power, tank volume and tank material, machine dimensions including handles, water inlet arrangement and working voltage, all of which are useful once they are confirmed as belonging to the machine you are buying and not to the family.
The rows that most often go missing on a machine-tool enquiry are the ones that decide reach and labour: delivery hose length, lance length and what the operator has to carry at the end of it, and the standard accessory set that ships in the crate. Ask for those rows. A fixed unit that cannot reach the far side of a machine without being moved needs a handling answer, not a bigger boiler.
The fixed-versus-mobile choice has a limit of its own
A machine-tool shop usually has many machines of different ages and envelopes, and a cleaning system has to serve more than one. That is where the fixed and mobile question starts. A fixed unit is fed from site services and stands at a position; the mobile units in this supplier's cleaning range are presented with their own supply and positioned around indoor garage bays and tight outdoor parking. Those positioning statements come from vehicle work, and a machine shop is not a car park, so treat them as something to test rather than a promise.
Settle the question on a shop drawing instead of a brochure. Mark each machine envelope, then mark the point from which the operator stands, and check three things for each machine: can the lance reach the farthest surface from that position without the operator crossing the machine; is there a power and water point that close; and can the unit and its hose be moved to the next machine without a second person. On the PowerDe cleaning equipment range page, the mobile models and the fixed models are shown as different families, so the reach and services question has to be answered per family and per shop layout.
Reach and dwell cap the area one operator can clean in a shift
Buyers often ask for an area rate and expect one number. The honest answer for a machine tool is that the number is per machine envelope and per surface list, and it is capped by four things: the distance the operator can work from one standing position, how many exclusion items have to be shielded before the first pass and unshielded after the last, how much dwell the crust needs, and how long the machine takes to dry and be re-checked before the next step in production. A quoted hourly figure that ignores shielding and drying will look optimistic on paper and will not survive the first real run.
Two measured runs on one machine, timed in named blocks, give a better planning figure than any catalogue. Time isolation and cooling, shielding, the pass itself, dry and re-check, restore and hand back. Add the containment set-up and clearance to those blocks. What you get is a per-machine figure that can be multiplied by the machines on the list, which is what the production planner needs.
The machine cannot reach inside, and the residue inside is the bigger problem
Steam on a machine tool is an external cleaning method with a hard boundary at the open parts of the machine. Inside the working envelope the real difficulty is different: oil carried into guideways, mixed with swarf, forming paste on the ways, and oil in the chip conveyor and sump. A wand does not solve that, and directing a wand at an open track is how slideway lubricant is stripped and a machine is damaged. The limit is not a quality of the steam; it is the design of the machine, and it is why the exclusion list is written before the cleaning parameters.
Whatever the steam trial settles, it settles it for the panels, guards, conveyor exterior, cabinet exterior and base. The interior stays on the machine's own maintenance routine, on consumable intervals and on the filter and separator schedule. Anyone presenting steam as the answer to internal contamination has described a different project.
What the supplier's marketing claims do not cover
The site describes high-temperature steam cleaning as a way to raise efficiency while cutting water use, labour intensity and reliance on chemical detergents, and it also offers customized steam cleaning equipment as a service. Those are the claims a buyer is being invited to trust, and they are the exact claims a bounded trial is designed to test. Steam cuts chemical use when the deposit comes off with heat; it does not cut chemical use when the shop still needs a separate degreaser for the excluded parts. Steam cuts water use compared with a hose when the mode is chosen per surface; it does not cut water when the operator runs the wet mode over everything because it is faster.
The same caution applies to the numbers a company page carries. The site's own totals for patents, projects and technical staff are not stated consistently from one page to another, so they are not a comparison tool for choosing equipment. Judge the quotation on the rows for the unit quoted, on how the exclusion list is handled, and on what the trial produced.
One bounded trial settles the limits you care about
Every limit above becomes a fact you own through one short, bounded trial on one machine of the type you clean most. Set the acceptance standard in advance, and write the stop conditions as well: run-off that cannot be contained, water entering a prohibited area, a coating that lifts, or a surface that fails the standard. Fix the scope to two or three surfaces, one of them the worst crust you have, and mark the test patches with tape so the before and after can be photographed against a boundary rather than argued about.
Run the trial with one row per patch, and with the person checking the result not the person holding the wand. Record the mode used per patch, the dwell, the time taken, the shielding time, the water actually consumed if the unit can show it, and where the run-off went. A trial that produces a one-page standard per machine family is worth more than a trial that produces enthusiasm.
Write into that page the limits the trial found as well as the results, in plain language, and give it a review date. That page is what stops the next shift from repeating the trial, and it is what a quotation from a second supplier is finally measured against.
