A supplier brochure can say that steam cuts grease. It cannot say what the method will do to the caked lubricant on your own gearboxes, guides and frames, on your surfaces, with your people. That question is answered on the shop floor, in a half-day, with a piece of tape and a camera. The procedure below is written for maintenance and cleaning staff who need a defensible result, not a sales demonstration.
Start with what "clean" has to mean on each machine
Before any equipment is moved into the shop, write down what a passing result looks like for each area you intend to test. "Clean" is not a usable acceptance statement. "No visible grease film on the guard surface when viewed at a low angle under the shop lights" is. Write one such sentence per area, in plain language, and agree it with the person who signs off maintenance work. Typical test areas on factory machinery are machine frames and guards, the outside of gearboxes and drive units, non-critical panels and stands, and the tops of beams where dust and oil have bonded into a dark crust.
Just as important is what you exclude from the test. Bearing bores, way covers, electrical cabinets, motor fan vents, encoder and sensor cables, and any opening without a seal stay out of scope unless you have a plan to protect them. A factory machinery degreasing trial that floods an unprotected junction box teaches you nothing about the cleaning method and costs you a shift.
Classify the grease before choosing test points
Grease on factory machinery is not one substance. It arrives in three states, and heat works differently on each. Choosing test points without knowing which state you are testing is the most common reason a trial gives a misleading answer.
| Grease state | How to recognise it | What a fair test must show |
|---|---|---|
| Fresh grease and oil film | Soft, transfers to a rag, dark from fine dust but still smeares | Whether one steam pass plus a wipe removes it without scrubbing |
| Oxidised, hardened film | Tacky-to-hard varnish-like layer, edges lift with a fingernail, does not smear | How long heat must dwell before the film releases, and whether residue remains |
| Grease bound with dust or swarf | Crusted buildup in corners, on top surfaces, gritty when pressed | How much solid matter must be removed dry first, and what the steam step adds |
Pick two or three points per state, all of them reachable without disassembly, and mark each with tape. Note the surface at each point: painted sheet steel, bare cast iron, plastic covers, printed labels and decals each react differently, and you will check them separately after the test.
Set the test up so the result is readable
A trial fails when everything is changed at once. Two habits make the outcome interpretable:
- Keep a control. Tape off half of each test point and do not touch it. After cleaning, the untouched half is your comparison under the same light, and your photograph pair is honest.
- Change one variable at a time. Fix a starting distance and pass speed, then vary only one of them if the first pass fails: dwell time, then distance, then number of passes, then the steam mode. Write down what you changed and what happened.
Photograph every marked point before you start, from a fixed standing position, so the after-photos are taken from the same spot. This matters more than any other record-keeping habit, because a high-temperature steam grease removal result is judged by comparison, and a comparison without a "before" is an opinion.
Run the test in a fixed order
- Stop the machine, apply lockout/tagout, and let hot surfaces cool to a temperature your staff can touch briefly. Put on gloves and eye protection; steam and splashed hot runoff burn even at low pressure.
- Remove loose swarf, dust and thick buildup dry first, by brushing and scraping into a pan. Steam is not a substitute for this step, and skipping it is the second most common cause of a failed trial.
- Cover or tape the excluded items: bearing openings, cable glands, nameplates you want to keep readable, and any opening that drains into the machine.
- Start with dry steam on one test point, holding the nozzle at your agreed distance and moving at a steady, observed speed. Dry steam carries less water and gives the heat; note how long the surface needs before the grease softens.
- Wipe with a cloth you have agreed on in advance, the same cloth type and the same pressure each time, and turn to a clean face deliberately. The wipe is part of the method, not a courtesy afterwards.
- On the next comparable point, try wet steam, which adds moisture and rinse action and suits thicker, oxidised film. Compare the two halves of your notes rather than your impressions.
- Collect the runoff as you go with a squeegee and a pan. Where it goes is a real constraint: oily rinse water that reaches a yard drain may need to meet the same local drainage rules as any other wash water.
Check during the test, and check again after drying
During the test, watch for release: does the film lift within your agreed dwell, or does it smear and redeposit? Watch the runoff: water running clear is not proof of a clean surface; water carrying released grease for a while, then running clear, is a better signal.
After the surfaces dry, walk the test points at a low angle under the shop lights and compare each cleaned half with its control. Then look for the delayed problems, and re-check them again at the end of the shift:
- A dull bloom of rust on bare cast iron or machined ways that were left un-oiled after cleaning.
- Water spots or dulling on painted or coated sheet.
- Lifted edges on labels and decals.
- Water that migrated into seams, drill holes or near bearing points, found by shining a light into gaps and wiping with a clean white cloth.
Re-oil or re-protect any bare metal surface that the trial cleaned, before you call the day finished. Removing grease also removes the thin protective film that was under it.
Read the machine's data sheet while you test, not after
The numbers on a specification table tell you what your test is allowed to assume. Take the PowerDe HW02 fixed steam cleaning machine data sheet as a worked example: it lists a steam temperature of 160°C and a vapour pressure of 0.8 MPa, which set how fast heat softens grease and how much dwell you should expect; a 6 kW heater and an 80 L stainless tank, which set the working cycle and how often the trial must pause for water and heat recovery; a tap-water inlet and 220 V supply, which your electrician and plumber must confirm at the actual position; and a switch between dry and wet steam, which is exactly the variable your test compares. The machine also lists leakage, short-circuit, high-temperature, high-voltage and water-shortage protection; those protect the machine, not your bearings or your circuit, which still need the site checks described above.
One caution before you reuse this example: the HW02 product page documents vehicle exterior, interior and engine-compartment cleaning. Factory machinery degreasing is a different duty, so get the manufacturer's written confirmation that the surfaces and grease types in your test fall within the machine's intended use before you treat a successful trial as a reason to order.
Record the result on one page, then decide
Write the trial onto a single sheet while it is still fresh. One page is enough, and anything longer will not be read. It should carry, for each test point: the location and grease state; the surface material; the settings used (mode, distance, dwell, passes); the immediate result against your acceptance sentence; the delayed findings after drying and at end of shift; before-and-after photos from the marked position; and the time the point took, including setup and protection. That last column turns your trial into a schedule someone can plan a shutdown around.
Then read the sheet and decide. A pass on frames, guards and outer surfaces supports a limited, written scope with the protected items listed and the excluded items named. A mixed result usually means the method works with a defined sequence, such as dry removal plus dwell plus wet steam on the heavy points, and that sequence has to be written into the procedure and taught to the operators. A clear failure on oxidised crust tells you the deposit is beyond what heat alone will do in a practical time, and that scraping, a different method, or a shorter cleaning interval is the honest answer.
Be clear about what the test does not prove. It does not clean the inside of the machine, it does not verify hygiene, and it does not predict throughput across twenty machines from three points. It answers one question well: whether steam-based oil and grease removal works on the specific surfaces and deposits you tested, under your conditions, in the time you have.
Before ordering, close the open questions with the supplier
Take the record sheet to the supplier and ask the questions your own trial could not answer: the steam hose and cable reach, so you can see whether one position really covers the machines you tested; warm-up time and the working cycle between refills; the nozzle and brush attachments suited to frames and guards; which protective functions the machine includes and what they do not cover; operator training and spare parts; and written confirmation on the intended-use question raised above. A supplier who answers these in writing has effectively run a second trial on your behalf.
You can send your test record and photographs to PowerDe through the contact page to discuss whether your results fall within the equipment's documented range.
