How do you make an electronics enclosure waterproof (IP67) for production?

To make an electronics enclosure waterproof for production, pick the rating first, then handle three things: seal the joint between the housing halves, seal every opening (buttons, ports, speakers, windows), and vent the air inside, which expands and contracts with temperature and pushes and pulls on the seals. For IP67, dust-tight and able to survive 1 m of fresh water for 30 minutes, a first run usually seals the joint with a gasket or O-ring squeezed by screws, so units can be opened and fixed; ultrasonic welding seals the halves for good and pays off at higher volumes. Each opening gets its own sealed part, a breathable vent lets the air inside follow the air outside, and on the production line every unit gets an air leak test of a few seconds. Water tests are for development and for samples.

In parts cost, sealing usually adds a few dollars a unit, not tens: at distributor prices in November 2026, an IP67-rated USB-C port with its gasket costs about $1.15 at a few hundred units against about $0.50 for a standard one, and a breathable vent about $1.30 at 1,000. The larger costs are one-time: design and test rounds, a stiffer housing, a welding horn and fixture if you weld, a leak-test fixture, and a test report if you print a rating on the box.

What do IPX4, IPX7, IP67 and IP68 mean?

An IP (Ingress Protection) code from the international standard IEC 60529 has two digits: the first for dust and solid objects, the second for water. An X means that part wasn't tested.

• IP6X means dust-tight, tested with fine dust and a vacuum inside for up to 8 hours; IP5X means some dust gets in, but not enough to matter.
• IPX4 is splashing from any direction. IPX5 and IPX6 are water jets: 12.5 liters a minute from a 6.3 mm nozzle, and 100 liters a minute from a 12.5 mm nozzle, at 2.5 to 3 m for at least 3 minutes.
• IP65 and IP66 are dust-tight and resist those water jets; they're common for outdoor products that see rain and hoses but never go under water.
• IPX7 is immersion: 30 minutes with the lowest point 1 m under fresh water. IP67 is often sold as waterproof, but it's a tested level of water resistance: temporary immersion, not permanent submersion.
• IPX8 is immersion beyond IPX7, at a depth and time the maker states, such as 1.5 m for 30 minutes or 2 m for an hour. IP68 on its own doesn't say how deep.
• IP67 doesn't include IPX5 or IPX6. Immersion is a slow, even push of about 10 kPa at 1 m; a jet is 30 to 100 kPa from a nozzle and can push past a lip or a button membrane that holds under still water. A product that passes both is marked with both, such as IP66/IP67.
• US enclosure ratings. Industrial cabinets often use NEMA types instead, such as NEMA 4X for hose-down and corrosion and NEMA 6 for submersion; they aren't exact equivalents of IP codes.
• Which one fits your product. As a rough guide: rain and splashes call for IPX4; a hose or a shower, IPX5 or IPX6; a drop in a puddle or a sink, IPX7; and going under on purpose, IPX8. Each step up costs more in design and testing, so pick the lowest rating that covers how people will really use the product.

Do you need a lab test to claim IP67?

No general US rule requires a third-party lab test before you print IP67 on a consumer product; the maker declares the rating. But US advertising law expects you to have evidence for a performance claim like that before you make it, so base it on a test report to IEC 60529, on units built the way production will build them; retailers and business customers may ask to see it. IEC 60529 passes a unit if any water that got in is harmless, so write your own stricter limit, usually no water at all, into the test plan. One lab lists about two weeks for its splash and jet tests; ask your lab how many samples it needs, and send spares.

How do you seal the housing joint?

The table compares the common ways to seal the joint between two housing halves: whether the product can be opened again, the one-time and per-unit cost, what to watch for and where each fits. Costs are from component makers and molding and welding guides in 2025 and 2026.

Method	Can it be opened again?	One-time cost	Added cost per unit	Watch for	Fits
Gasket or O-ring with screws	Yes, and the seal can be replaced	A groove in the existing mold; a die or dispenser for foam or dispensed gaskets	Cents to tens of cents for the seal, plus screws, inserts and assembly time	The right squeeze, stiff walls, even screw torque, no flash on sealing faces	First runs, products that are serviced or may still change
Ultrasonic weld	No; it has to be cut open	A horn, about $300 to $3,000 depending on the part's size and shape, plus a fixture to hold the part; many molders own the welder	The horn and fixture spread over the run: dollars a unit on a run of hundreds, under a cent at hundreds of thousands; about a second of machine time per weld	Joint design, dry plastic, and parts inside that vibration can harm	Settled designs at higher volumes
Adhesive or pressure-sensitive tape	Usually not without damage	A die for cut tape	About $0.05 to $0.50 a part	Heat cycling and sunlight weaken it	Display windows, lenses, back covers
Overmolded rubber or silicone seal (two-shot)	The seal stays on the part	A two-shot mold set costs about twice a single-shot mold	Small; no loose gasket to fit	Bond and mechanical interlock between the two materials; compression set at high temperature	Tens of thousands of units a year and up
Potting (filling the inside with resin)	No; removal usually destroys the board	Dispensing setup	Material, weight and curing time	Heat, weight, no repairs, indicator lights hidden under the resin	Harsh, sealed-for-life modules

Gaskets and O-rings. A face-seal O-ring is usually squeezed about 20 to 30% of its thickness, and a foam gasket about 25 to 35%, depending on the grade; too little and it doesn't seal, too much and it stays flattened and stops pushing back (a permanent set) or cracks the housing. Width matters: in one gasket maker's test at about 10 kPa of pressure, silicone gaskets of the same thickness leaked 1.5 mL a minute at 12.7 mm wide and 47.3 mL at 3.2 mm, so leave room in the wall for the seal. Put the seal inside the screw line so water can't follow the screws in, space the screws closely and tighten them to a set torque, and stiffen thin walls with ribs, because a plastic housing bows between screws. Keep flash (thin fins of plastic that squeeze out where the mold halves meet, along the parting line), gate marks (the small nub where plastic entered the mold) and ejector-pin marks (round marks from the pins that push the part out) off the sealing faces; a small amount of flash can break a continuous seal. Some O-ring compounds can crack polycarbonate where they press hardest, so check the pair with the seal maker.

Ultrasonic welding. A horn vibrates one half against the other and melts a small molded ridge, an energy director, or a designed overlap, a shear joint, which is preferred for watertight seals. ABS and PC weld well; nylon and polypropylene are harder, and nylon has to be dry. The weld is permanent, and some parts inside, such as crystals and MEMS sensors (tiny motion and pressure sensors), can be harmed by the vibration, so check with their makers.

Overmolded seals. A rubber-like plastic (TPE) or liquid silicone (LSR) molded onto the housing replaces a loose gasket; ask for compression-set data at your top temperature, where many TPEs fall behind silicone. A two-shot mold costs about twice a single-shot one and usually pays off only at tens of thousands of units a year; at a few hundred, a separate gasket is cheaper.

Conformal coating. A thin film sprayed or brushed onto the board protects it from moisture and condensation, but it doesn't replace sealing the housing for immersion; use it as a backup behind the seals.

How do you seal buttons, ports, speakers and windows?

• Buttons. A silicone keypad or membrane clamped in the housing over a standard switch, a sealed tactile switch behind a flexible cap, or capacitive touch through a solid wall, with no hole at all. A sealed switch costs pennies more than a plain one; the cost is in the housing design.
• Charging and data ports. An IP67-rated USB-C receptacle keeps water from passing through the connector into the case, and its gasket seals the connector to the housing. The socket itself still gets wet, and plugging in a charger while it's wet can corrode the pins; tell users to let the port dry before charging, or add moisture detection that holds off charging, as many phones do. Some sealed connectors hold their rating only with a plug or cap fitted, so check the rating with nothing plugged in. Pogo-pin contacts or wireless charging keep the case closed; keep exposed contacts unpowered until the device is on its charger, because sweat and power together corrode them.
• Speakers and microphones. A waterproof acoustic membrane, usually expanded PTFE (ePTFE, the breathable membrane material used in rain jackets), lets sound through and keeps water out. It costs some sound: under 0.1 dB for splash protection, 0.4 to 1.4 dB for IP67 or IP68, and up to about 4 dB for deep immersion, in one maker's figures.
• Windows and light pipes. Windows are usually bonded with a die-cut adhesive foam tape or a liquid adhesive; light pipes are molded in place, sealed with an O-ring, or replaced by a thin, translucent spot in the housing.
• Cables. A cable gland or a cable exit molded around the cable jacket.

Why does a waterproof enclosure need a vent?

A sealed case holds the air it was closed with. Seal a case at 20 °C, heat it to 60 °C in the sun, and the air inside pushes out with about 140 mbar. Many seals let some of that air escape; then, when rain cools the case back to 20 °C, it pulls in with about 120 mbar, more than the roughly 100 mbar of the 1 m immersion test. Over many cycles this breathing out and pulling in draws moist air past the seals, and the moisture condenses inside. A breathable vent (also called a breather or pressure-equalization vent), a small ePTFE membrane that passes air but not water, lets the pressure equalize, takes the load off the seals and lets water vapor out. Many vents are themselves rated IP67 or IP68. No vent removes condensation completely, so keep the board's sensitive parts off the coldest wall.

How do you test a waterproof enclosure?

• In development. Sink units 1 m deep for 30 minutes with a dry tissue or water-indicator stickers inside, and test again after temperature cycling and drop tests, because seals that pass when new often fail after the case flexes. Also dunk units straight from a warm chamber into cool water: the inside cools, pulls in, and finds leaks a room-temperature dunk misses. Spray-test too if the product will see jets or a shower.
• For the claim. A lab test to IEC 60529 for the rating you print, on units built the way production will build them, with your own pass limit written into the test plan.
• On the production line. Every unit gets an air leak test (a pressure-decay test) instead of water: the tester pressurizes the case or a hood around it and measures the pressure drop, in about 7 seconds for a small part. One leak-test maker, testing at about 100 mbar (the pressure at 1 m of water), suggests a limit of about 3×10⁻² mbar·l/s (about 2 cm³ a minute) for a plastic housing that can tolerate a few drops, and 5×10⁻³ (about 0.3 cm³ a minute) when no water at all is acceptable; set your own limit by testing units with known leaks. On a larger housing, the tighter limit may need a more sensitive tracer-gas tester than a plain pressure-decay one. The same test catches a missing O-ring. In that maker's test with fine glass tubes under 1 m of water, holes smaller than about 20 micrometers held water back by surface tension, and a 40-micrometer hole let in a drop about every one and a half minutes; real leak paths in plastic behave differently.
• Vents and membranes on the line. A breathable vent passes air by design, so the leak test has to work around it: fit the vent after the test, or have the fixture seal it off and check the vent separately. Keep the test pressure within what the membranes, speaker and seals can take, often only 100 to 200 mbar.
• Samples per lot. Put a few units from each lot (a batch made together) in water, more often at the start of a run and after any change of gasket batch, mold repair or screw-driver setting.

Common leak points in a first run include gaskets that take a set, sealing faces that warp, flash on the parting line, uneven screw torque, port seals, button membranes and window adhesive. When a lot fails, screwed housings can be opened and re-gasketed; welded or potted ones are usually scrapped.

Does an IP67 rating cover salt water, pools and batteries?

IP tests use fresh water at about room temperature. A rating says nothing about salt water, pool chlorine, soap, sunscreen, hot water or the pressure of a swimmer's arm. Products made for swimming often state water resistance to ISO 22810, the watch standard, instead. Choose seal materials for the liquid: EPDM handles water and chlorinated water well but swells in oils, petroleum grease and many lotions; silicone is the usual choice for skin-contact products, and fluorocarbon (FKM) where oils and chemicals matter. Lubricate seals only with a grease the seal and housing makers approve; some greases and oils can crack polycarbonate where it's under stress, depending on what's in them. Salt water conducts, so it can short battery cells and corrode contacts long after the device dries; keep battery terminals and charging contacts sealed or unpowered. A fully sealed case around a lithium cell also needs somewhere for gas to go if the cell vents; ask your safety lab and the cell maker how the case should relieve pressure.

Example: one outdoor sensor, two ways to seal it

This is an illustration, not a customer project. The product is made up, and so are the numbers, except the two part prices taken from the distributor prices above.

In this made-up case, a handheld outdoor sensor with a USB-C port and one button needs IP67, with a made-up first run of 500 units and a made-up build cost of $45 a unit before sealing.

• Parts both versions need (partly real prices): an IP67 USB-C port with its gasket, about $0.65 more than a standard port at the distributor prices above, a breathable vent at about $1.30 (the 1,000-unit price above), and a sealed button at a made-up $0.30 more. With 500 units, that's a partly made-up $1,125.
• One-time costs both need (made-up numbers): a leak-test fixture at $2,500 and a lab test report at $1,500.
• Version A, O-ring and screws (made-up numbers): an O-ring at $0.20, four screws and inserts at $0.30 and a minute more of assembly at $0.50, so $1.00 a unit, $500 for 500 units, and the groove goes into the mold at no extra cost.
• Version B, ultrasonic weld (made-up numbers): a horn and fixture at $3,500 and about $0.10 a unit in welding time, $3,550 for 500 units.

If 3% of the units, 15 of 500, fail the leak test in this made-up case, version A opens them and fits new O-rings at $2 each, $30; version B scraps them at $45 each, $675. With these made-up numbers, welding saves $0.90 a unit in sealing, but every leak-test failure costs $43 more to scrap than to re-gasket. At this made-up 3% that's about $1.29 a unit, more than the saving, so welding never pays back; at 0.5% it pays back its $3,500 after about 5,100 units, and with almost no failures after about 3,900. So the first 500 go with screws and an O-ring, and welding waits until the design is settled and few units fail the leak test.

The general rule: seal a first run with screws and a gasket, so failed units can be reopened and the design can still change; move to welding or an overmolded seal once the design is settled, few units fail the leak test and the volume pays for the tooling; and air-test every unit either way.

What should you ask your manufacturer and test lab?

• Which rating, tested how (immersion only, or jets too), on which units, with what pass limit (no water at all, or harmless water), and who issues the report?
• The gasket's material and grade, its squeeze target, and the groove drawing.
• The screw torque, and how it's set and checked on the line.
• The leak test: method, test pressure, pass limit, fixture cost, every unit or a sample, how it's checked against a known leak, and how it handles the vent.
• How sealing faces are kept free of flash, gate marks and ejector-pin marks.
• How each port, button and window is sealed, and which vent is used where.
• For each sealed connector, whether its rating holds with nothing plugged in, or only with a plug or cap fitted.
• How many units go in water from each lot, and what happens to units that fail.

For the plastic the housing is made of, see Which plastic is best for an electronics enclosure; for metal housings, Sheet metal, aluminum extrusion or CNC; and for checking a first run before it ships, How do you inspect a first production run before it ships?

Where we come in

If your product has to survive rain, sweat or a drop in the sink, this is one of the situations Anamor takes on. We design each part for the process that will make it, seals included, and our quotes list setup costs, such as tooling and fixtures, separately from unit prices at the quantities you're planning.

Anamor takes US hardware teams with a working prototype into their first production run: we redesign the product for production, line up partner factories and suppliers in the US and overseas, price it at your quantities, and run the build through to shipping.

Send what you have: photos of the prototype, CAD if you have it, the rating you need and where the product will be used, and how many you plan to make. Need an NDA? We'll send our mutual NDA, or review yours, before you send files. Within two business days, a real person on our team will reply with a free first look at your production run and a few times to talk.

Frequently asked questions

What does IP67 mean?

IP67 is an Ingress Protection code from IEC 60529. The 6 means dust-tight; the 7 means the product survived 30 minutes with its lowest point 1 m under fresh water. It doesn't cover water jets, which are IPX5 and IPX6, and it says nothing about salt water, pool chlorine, soap or hot water.

Do you need a lab test to claim IP67 in the US?

No general US rule requires a third-party lab test before you print IP67 on a consumer product, but US advertising law expects evidence for a performance claim like that. Base it on a test report to IEC 60529, on units built the way production builds them, and write your own pass limit, usually no water at all, into the test plan.

Why does a waterproof enclosure need a vent?

A sealed case pushes out when it heats and pulls in when it cools. If hot air escapes past the seals, cooling from 60 °C back to 20 °C pulls in about 120 mbar, more than the 1 m immersion test. A breathable ePTFE vent equalizes the pressure, takes the load off the seals and lets water vapor out.