To clean an oil resistant borescope, wipe the probe with a lint-free cloth lightly dampened with a cleaner the manufacturer approves, clean the lens tip separately with a fresh swab, dry everything, and inspect the optic before you store it. "Oil resistant" means the probe jacket tolerates contact with oil. It does not mean the scope can be soaked, pressure-washed or cleaned with any solvent on the shelf. This guide covers the routine, the mistakes that ruin optics, and the signs that the scope needs service.
TL;DR
- Oil resistance describes the probe jacket and seals. Check the manual before you immerse, spray or soak anything, and never treat it as permission to pressure-wash.
- Remove loose grit first, then wipe with a lightly dampened lint-free cloth. Put cleaner on the swab, never directly on the lens.
- Avoid abrasives, harsh solvents, ultrasonic baths and compressed air blasted into connectors or the articulation section.
- Dry fully, check the lens under good light, then store the probe in a loose coil or its case.
- Oil inside the housing, a hazy image that will not clear, or stiff articulation means stop and call for service.
Table of Contents
- What "oil resistant" actually means on a borescope
- What to gather before you start
- Step-by-step: cleaning the probe and lens
- Which cleaners and methods to avoid
- Industrial borescope versus veterinary endoscope cleaning
- What to do if oil gets inside
- Drying, inspecting and storing after cleaning
- How often to clean
- When to stop and seek manufacturer service
- Perspective: what we see across oily-environment scopes
- Choosing a scope that is easier to keep clean
- Find the right borescope and accessories
- FAQ
- Sources
What "oil resistant" actually means on a borescope
Manufacturers use the phrase for the outer jacket of the insertion tube and the sealed tip. The material is chosen so that engine oil, hydraulic fluid or cutting oil does not swell, soften or crack it during a normal inspection. That is a statement about material compatibility. It says nothing about the handle, the connector, the battery compartment or the monitor.
It also differs from a water rating. Many probes carry an IP67 rating, which under the common definition means dust-tight and able to be submerged in water up to one metre for up to 30 minutes. Two things follow:
- The test uses clean water, not oil, solvent or detergent. Oil is thinner than many people assume and creeps into seams that water does not.
- The rating usually applies to the probe only. A hand-held monitor or a camera head is typically not part of it.
So a probe can be dunked in a bucket of soapy water and survive, yet still be harmed by a strong degreaser that attacks the tip adhesive. The rule is simple: the manual of your exact model decides what is allowed. If you no longer have it, ask the supplier before you experiment.
What to gather before you start
A good cleaning kit is cheap and small. Keep it with the scope so the routine does not get skipped.
- Lint-free wipes or microfiber cloths, kept in a sealed bag so they stay free of dust
- Foam or lint-free swabs for the lens tip
- A soft brush or a hand blower bulb for loose grit
- The cleaner named in your manual (often a mild detergent solution, or an optical cleaner for the lens)
- Nitrile gloves, so fingerprints do not land on the optic and oil stays off your skin
- A clean, flat, well-lit surface covered with paper or a fresh towel
For veterinary users, keep this kit separate from anything used on patients. A borescope used on equipment, a rigid scope used in a clinic and a flexible veterinary endoscope each have different cleaning rules, covered below.
Step-by-step: cleaning the probe and lens
1. Power down and detach
Turn the unit off, remove the battery or unplug the power, and detach any accessory tip, mirror or hook. Cleaning a live scope risks a short at the connector and washes dirt into the electronics.
2. Remove loose debris first
Blow or brush away dust, metal fines and grit before any wiping. Optical guidance published in a peer-reviewed review of caring for optical surfaces puts dust removal first for a reason: wiping a gritty surface drags particles across the glass and scratches it.
3. Wipe the probe from the handle toward the tip
Dampen a lint-free cloth lightly with the approved cleaner and wipe the insertion tube in one direction, moving from the handle toward the tip. This pushes oil away from the connector end. Use a fresh section of cloth as it picks up oil, rather than rubbing the same film back and forth. Heavy oil can first be blotted with a dry cloth.
Oil from a leaking engine, for example, tends to carry a layer of dirt and combustion residue. If you inspect a vehicle with failing oil pump seals, expect the probe to come out with a thicker, stickier coating, so plan for two or three cloth passes instead of one.
4. Clean the articulation section gently
On articulating probes, the bending section is a woven or segmented sheath. Wipe it with the cloth in the relaxed, straight position. Do not bend it hard while oily and do not scrub it with a brush, because grit lodged in the sheath wears the control cables over time.
5. Clean the lens tip as its own job
The lens is where cleaning quality shows up in the image. The same optical cleaning guidance says to consult the manufacturer first, apply cleaner to a swab or tissue rather than directly to the optic, use light pressure, and avoid cleaners that are not approved for plastic lenses. In practice:
- Put one or two drops of approved optical cleaner on a fresh swab.
- Starting at the center of the lens, wipe outward in a gentle spiral.
- Use a new swab for every pass. A used swab only redistributes oil.
- Finish with a dry swab to lift remaining streaks.
Small-diameter scopes often have a plastic or coated window. A cleaner that is safe on glass may cloud it, which is why the manual matters more at the tip than anywhere else.
6. Dry, then inspect
Let the probe air dry on a clean towel, or pat it dry with a fresh lint-free cloth. Do not apply heat. Then turn the scope on and look at a plain white sheet of paper. Streaks, haze or dark spots that stay in the same place on the screen when you move the probe are on the lens or inside it. Streaks that wipe off are on the lens. Spots that do not are a service issue.
Which cleaners and methods to avoid
Most borescope damage during cleaning comes from good intentions and the wrong product. Avoid the following unless your manual explicitly allows them.
| Avoid | Why it causes harm | Do this instead |
|---|---|---|
| Abrasive pastes and scouring pads | Scratch the lens coating and score the jacket | Soft swab with approved optical cleaner |
| Strong solvents such as acetone or lacquer thinner | Can soften jacket material and attack tip adhesive | Mild detergent solution or the cleaner named in the manual |
| Spraying cleaner onto the lens or handle | Liquid runs into seams and connectors | Dampen the swab or cloth, not the scope |
| Pressure washing or high-pressure sprays | Forces liquid past seals, even on waterproof probes | Wipe by hand |
| Ultrasonic baths | Vibration can loosen bonded joints and fiber bundles | Manual cleaning only unless the maker approves it |
| Compressed air at close range | Drives grit and oil into the connector and articulation section | Hand blower bulb at a distance |
| Reusing one dirty swab | Spreads oil across the optic | Fresh swab each pass |
A note on forum advice. Search results for this topic include shooters discussing bore-cleaning compounds and abrasive pastes for firearm barrels. Those products are for steel barrels. They have no place anywhere near a borescope probe or lens.
Industrial borescope versus veterinary endoscope cleaning
The two are often confused, and the difference matters for anyone who owns both.
Industrial borescopes are cleaned for appearance, image quality and longevity. The goal is to remove oil, grease and dirt so you see clearly and the jacket lasts. There is no patient contact, so disinfection is not part of the routine.
Veterinary and medical endoscopes are cleaned to control infection as well as to protect the instrument. Veterinary infection-control guidance from Zoetis notes that flexible endoscopes have intricate internal designs that are easily damaged, so cleaning and chemical compatibility must follow the protocol in the manual. The same document says that skipping leak testing can let organic material enter the internal cavity, leaving a lasting contamination reservoir.
So if your clinic uses a borescope-style videoscope for animal work, do not apply the industrial routine above and call it done. Follow the reprocessing steps in our guides to endoscope sterilization for vets and industry and sterilization in veterinary endoscopy. And never move a scope from oily industrial work to a patient without full reprocessing approved for that model.
What to do if oil gets inside
Oil that stays on the outside is a cleaning problem. Oil that gets inside is a repair problem. Signs it has happened:
- A haze or oily rainbow pattern that appears behind the lens and does not wipe away
- Fogging that returns after drying
- LED lights that dim or flicker after exposure to oil
- Oil visible at the handle, connector or articulation collar
- A control lever that feels gummy or stiff
If you see any of these:
- Stop using the scope. Powering it on can short wet electronics.
- Remove the battery or power source.
- Wipe the outside, cap the connector if there is a cap, and keep the probe straight and loosely coiled.
- Do not open the handle, flush the probe with solvent or leave it in a warm place hoping the oil dries out.
- Contact the manufacturer or a repair service. We offer endoscope repairs, and you can start from our repair and equipment page.
On a channeled veterinary scope, a sticky or blocked channel is a different issue with its own fix. See our guide to clogged endoscope channels before forcing anything through.
Drying, inspecting and storing after cleaning
A clean scope can still be damaged in a drawer. Finish the job properly.
- Dry completely. Moisture trapped in a case encourages fogging and corrosion at the connector. Leave the probe out on a clean towel until it is fully dry.
- Inspect the jacket. Run the cloth along the tube and watch for snags, flat spots, cuts or swelling. Oil-softened jackets show up as tacky or puffy sections.
- Test the articulation. Move the control through its full range slowly. It should be smooth and return to center.
- Check the image once more. Use the white paper test again after drying, because some residues only show once the cleaner has evaporated.
- Coil loosely. Follow the minimum bend radius in the manual. A tight coil kinks the tube and damages the fibers.
- Cap and case. Fit tip and connector caps and store in the case, away from heat, sun and oil spills.
For storage details across both vet and industrial gear, see our guide to storing endoscopic equipment. Before the next job, our guide on prepping an endoscope for inspection gives a short pre-use check.
How often to clean
Clean the probe after every oily job, even if it looks fine. Oil left to sit attracts dust, hardens in the articulation sheath and works its way into seams. A quick wipe takes a minute; a deep clean after weeks of neglect takes much longer and is less safe for the scope. Do a more careful lens and jacket inspection weekly if you use the scope daily. Anyone who shares one scope across a team should name one person responsible for the end-of-day routine, so it does not fall between people.
When to stop and seek manufacturer service
Send the scope for service rather than trying another round of cleaning when:
- The image stays hazy or spotted after two careful lens cleanings
- You find oil or moisture inside the lens window
- The articulation is stiff, gritty or does not return to center
- The jacket is cut, cracked, swollen or sticky in one section
- Lights or the monitor behave erratically after contact with oil
- A veterinary scope fails a leak test
If you are unsure whether a scope is worth repairing, our videoscope troubleshooting guide walks through common faults and what each usually means.
Perspective: what we see across oily-environment scopes
We sell and service both veterinary endoscopes and industrial borescopes, and the pattern in our repair queue is consistent: scopes rarely fail from oil itself. They fail from the cleaning that follows it. A harsh solvent, a scrubbing pad or a pressure spray does more harm than an hour of engine oil on a properly built jacket.
That is why we point buyers toward scopes designed for the job in front of them, and why we pair equipment with the accessories that keep it healthy: cleaning tools, valves, pumps and spare tips. A portable videoscope with a sealed probe and a clearly documented cleaning routine is cheaper to own than a bargain unit with no manual, and our range is built to give vets and inspection teams professional features at an affordable price.
Our advice is to treat the manual as part of the instrument, to clean at the end of each job, and to call us early when something feels off. A quick conversation costs far less than a failed lens.
Endoscope
Choosing a scope that is easier to keep clean
If you inspect oily environments such as engines, gearboxes, hydraulic lines or machinery, look for these features when you buy:
- A smooth, sealed insertion tube with a documented chemical compatibility list
- A removable or replaceable tip, so a damaged lens end does not mean replacing the scope
- A rating for the probe, with the limits of the handle and monitor clearly stated
- A manual that names approved cleaners
- Accessory availability and repair support in the United States
For clinic work, add compatibility with your reprocessing method and the ability to leak test where the design calls for it. Our guide to the best borescopes for vets and our article on using flexible borescopes for accurate diagnostics explain how to match a scope to the task.
Find the right borescope and accessories
We supply monitor-type SD-card videoscopes, portable pipe inspection videoscopes and micro fiber borescopes for industrial inspection, along with veterinary endoscopes, rigid scopes and accessories. Browse the full range on our borescopes page, or if you need a veterinary system, see our medical endoscopes and accessories.
If you are not sure which model suits an oily application, ask us before you order. We will help match the probe, tip and accessories to the job, and our team can also help with repairs on scopes you already own. Our endoscopy FAQ and inspection procedures page is a useful starting point for general questions.
FAQ
Can I use isopropyl alcohol to clean a borescope?
Only if your manual allows it. Some makers approve diluted alcohol for the jacket, but it can cloud or craze plastic lenses and weaken adhesives. If the manual is silent, use a mild detergent solution on the probe and ask the supplier which optical cleaner is safe for the lens.
Is an oil resistant borescope also waterproof?
Not automatically. Oil resistance refers to the jacket material, while a waterproof rating such as IP67 is a separate test with specific limits. Check the rating for the probe, and remember it rarely covers the handle, connector or monitor.
Can I pressure-wash or soak the probe to remove heavy oil?
No. Even waterproof probes are tested under defined conditions, not against high-pressure jets or strong degreasers. Blot heavy oil first, then wipe by hand with the approved cleaner. If a probe is caked in residue, contact the manufacturer for guidance.
Is cleaning an industrial borescope the same as cleaning a veterinary endoscope?
No. An industrial borescope is cleaned for image quality and durability. A veterinary endoscope used on animals also needs approved reprocessing and, for channeled scopes, leak testing, following the manufacturer's instructions for that model.
Sources
- How to care for and clean optical surfaces, PMC
- Practical Infection Control Guidelines, Zoetis
- What does IP67 rating mean