A European outdoor power equipment manufacturer came to us with a warranty problem on their cordless grass trimmer. The trimmer had a control panel with five silicone buttons: power, speed up, speed down, mode and lock. The customer had specified standard silicone rubber keypads, the same type used on TV remotes. The trimmers were sold to gardeners who washed down the unit with a high-pressure hose after every use. Two months into the field season, water had worked its way under the keypad bezel, and three out of five buttons had stopped registering. The contact pills on the PCB had oxidized, and the silicone itself had absorbed water and felt slimy. The buyer had assumed silicone was inherently waterproof. It is not: silicone rubber is sealed at the button, but if the keypad is not bonded to the panel, water wicks in around the bezel.
We redesigned the panel with a fully bonded silicone rubber keypad sealed to the housing flange, added a perimeter gasket, and specified Shore A 50 hardness instead of the softer Shore A 40 the original design used. The new keypads passed the IP67 immersion test and the high-pressure spray test, and the next season had zero warranty returns on the keypad. That project is the subject of this release. When you specify silicone keypads for outdoor or washdown equipment, the sealing is not a property of the silicone material; it is a property of how the keypad is bonded to the panel and how the bezel is designed.
This release compares unsealed, IP65 and IP67 silicone keypads on the parameters that matter in outdoor equipment, and maps each sealing level to the application it fits. We also cover the hardness and legend choices that survive ultraviolet sun, fuel and washdown chemicals.
Why silicone is not automatically waterproof
Silicone rubber itself is water-resistant, and a molded silicone button is a solid piece that water cannot pass through. The leak path is never through the button; it is around the keypad, between the keypad flange and the housing. A standard keypad sits in a cutout and is held by a bezel. There is a gap under the flange, and water wicks into that gap under spray. Once inside, it sits on the PCB contact pills, and the pills oxidize within weeks.
There are three ways to stop this. The cheapest is a perimeter foam gasket that seals the keypad to the housing when the bezel is screwed down, rated to IP65 for low-pressure spray. The next is a heat-bonded flange that fuses the silicone to a polyester or plastic carrier, rated to IP66. The most robust is a fully overmolded keypad with a bonded gasket and a sealed cable exit, rated to IP67 for temporary immersion. Each level costs more and is appropriate to a different exposure.
The leak path is around the keypad flange, not through the silicone; the sealing design determines the IP rating.
Unsealed vs IP65 vs IP67 silicone keypad: comparison table
| Parameter | Unsealed keypad | IP65 keypad | IP67 keypad |
|---|---|---|---|
| Sealing method | Bezel, no gasket | Perimeter foam gasket | Bonded flange + gasket |
| Dust protection | Partial | Dust-tight | Dust-tight |
| Water protection | Splashes only | Low-pressure jets | Temporary immersion |
| High-pressure washdown | No | No | Yes |
| UV / outdoor exposure | Indoor only | Covered outdoor | Full outdoor |
| Relative cost | Lowest | Moderate | Higher |
| Best fit | Remote, indoor appliance | Covered outdoor, dashboard | Garden tools, marine, washdown |
Hardness and legends for outdoor use
Outdoor keypads need a harder Shore A rating than indoor remotes. A Shore A 40 keypad feels soft under a bare finger but softens further in summer sun, and it wears quickly under gloved work gloves. For outdoor power equipment we specify Shore A 50 as the baseline, and Shore A 60 for keys that will be pressed with work gloves or boots. The actuation force rises with hardness, so a Shore A 60 keypad is specified at 180 to 250 grams so the press is still felt through a glove.
Legends on outdoor keypads take a beating from ultraviolet sun, fuel, oil and repeated washdown. Screen-printed legends on the silicone surface fade within one outdoor season. Laser-etched legends, where the legend is etched into the silicone and pigmented underneath, last the product life and resist fuel and UV. For any outdoor or washdown product, specify laser-etched legends; the small extra cost is recovered the first season.
Metal domes embedded under the silicone provide tactile feedback; the sealed keypad keeps water away from the contacts.
Which sealing level for which outdoor product
Indoor remotes and home appliances - unsealed. A TV remote, a washing machine panel or a kitchen appliance control never sees water spray, and an unsealed silicone keypad is the lowest-cost choice. The bezel holds the keypad in place, and the lack of gasket does not cause a field failure. This is the rare case where unsealed is the right answer.
Covered outdoor dashboards and instrument panels - IP65. A motorcycle dashboard, a covered ATV control panel or a solar inverter keypad sees rain but not direct hose spray. An IP65 keypad with a perimeter foam gasket handles rain and low-pressure wash. This is the standard covered-outdoor choice.
Garden tools, marine electronics, washdown equipment - IP67. A cordless grass trimmer, a chainsaw, a boat control panel or a food-industry washdown station sees high-pressure spray or temporary immersion. An IP67 keypad with a bonded flange and gasket is required. This is the sealing level that fixed our European outdoor power equipment customer's warranty problem.
Pair with the right circuit behind the keypad. The sealed silicone keypad sits over a PCB or a flexible printed circuit, and the contact pills close on copper pads. For curved outdoor panels, a membrane switch on FPC bends to the shape. The metal domes under the silicone provide the tactile click, and the dome sheet array aligns the domes to the pads. We supply the keypad, the circuit and the dome as one program so the sealing and the alignment are coordinated.
Selection checklist
1. Washdown exposure. If the product is hosed or pressure-washed, IP67. If it sees rain under a cover, IP65. If it stays indoors, unsealed. This single question rules out two options.
2. Hardness. Bare-fingered indoor use: Shore A 40. Gloved outdoor work: Shore A 50 to 60. A Shore A 40 keypad in summer sun will feel soft and wear fast on a garden tool.
3. Legend method. Indoor, covered: screen print is fine. Outdoor, UV, fuel, washdown: laser-etched. Screen-printed legends fade in one outdoor season.
4. Actuation force. Outdoor keypads pressed with gloves need 180g or higher. A 100g keypad is hard to feel through a work glove.
5. Cable exit. If the keypad connects by a flying lead, the cable exit is a leak path. Specify a strain relief with a sealed gland, or a board-mount keypad with a connector inside the sealed housing.
Common selection mistakes
The first mistake is assuming silicone is waterproof. The grass trimmer customer's warranty return started exactly this way. Silicone stops water through the button; it does not stop water around the flange. The keypad must be sealed to the housing.
The second mistake is specifying an IP65 keypad for a pressure-washed garden tool. IP65 handles low-pressure jets, not the high-pressure hose a gardener uses. The gap between IP65 and IP67 is the difference between a working season and a warranty return.
The third mistake is choosing Shore A 40 for an outdoor product. The soft, comfortable feel that works on a TV remote becomes a mushy, worn keypad on a summer-worked garden tool. Outdoor keypads run harder.
The fourth mistake is screen-printing legends on an outdoor keypad. The first season of sun and washdown wears the print off, and the user cannot tell which button is which. Laser-etched legends cost a little more and last the product life.
What we supply and test
At Shanyo we produce silicone rubber keypads in Shore A 30 to 70, with carbon or gold contact pills, embedded metal domes and laser-etched legends. IP65 and IP67 keypads are tested to the IEC 60529 rating on every batch: dust chamber for the dust rating, and immersion or spray for the water rating. We supply the test report with the shipment. Prototype keypads ship within 48 hours from a 2D drawing, and production tooling is cut within two to three weeks.
We supply custom OEM and wholesale silicone keypads for outdoor power equipment, marine electronics, industrial remotes and medical handhelds, with IATF 16949 and ISO 13485 quality systems covering automotive and medical programs. Contact Shanyo with your washdown requirement, glove condition and legend choice, and our engineering team will recommend the sealing level, hardness and legend method and quote factory pricing for your program.
Cost trade-off, stated plainly
An unsealed silicone keypad is the lowest-cost option because there is no gasket or bonding step. An IP65 keypad adds a foam gasket and a slightly tighter flange design, a modest per-piece increase. An IP67 keypad adds a bonded flange, a perimeter gasket and a sealed cable exit, and the tooling is more complex. On a five-button garden tool keypad, the gap between unsealed and IP67 is a small fraction of the finished part cost.
The mistake buyers make is reading that gap on the quote and specifying unsealed keypads everywhere. The correct comparison is the cost of a warranty return: a gardener who cannot start the trimmer because the power button has corroded wants a replacement unit, and the dealer takes it back. One avoided warranty claim pays for the IP67 gasket on thousands of keypads. For an indoor remote that never sees water, the unsealed keypad is the right economic choice.
There is also a tooling consideration. Unsealed keypads use a standard compression mold. IP67 keypads need a mold that forms the bonded flange and gasket in the same shot, and the tooling cost is higher. For a prototype run of fifty keypads, we can machine the flange and bond the gasket; for a production run of fifty thousand, the bonded mold wins on unit cost. We recommend the process based on your annual volume, not on a single sample price.
What we ask for before recommending a sealing level
To recommend unsealed, IP65 or IP67, we need four inputs: the washdown or spray exposure, whether the user wears gloves, the legend method (screen print or laser etch), and the annual volume. With those four numbers we can rule out the wrong sealing immediately and recommend the construction that fits. Missing the washdown input is the most common reason a first batch comes back with water-ingress complaints, because the buyer specified an unsealed keypad for a hose-washed garden tool without telling us.
Life and field reliability
The sealing does not change the silicone's feel, but it changes how the keypad behaves over years. An IP67 keypad holds its contact resistance within spec for the product life, because the sealed flange keeps water and dust away from the PCB. An unsealed keypad starts clean, wicks in water over time, and the contact pills oxidize. For a product expected to run for years outdoors, the sealed keypad is the more reliable choice even if the silicone itself is identical.
Flange, gasket and overmold details
Beyond the IP rating, the keypad must fit the housing cutout, bond to the flange, and exit through a sealed strain relief. We mold the flange to ±0.2mm tolerance, bond the silicone to the carrier in a single heat step, and supply the perimeter gasket as an integrated part rather than a separate foam piece. For overmolded keypads we bond the cable gland into the same shot, so there is no seam for water to follow. The result is a keypad that the buyer drops into the housing and screws down, with no separate gasket to assemble or lose on the production line.
We also run UV aging and fuel immersion testing on the legend as part of the approval, so the buyer sees the legend survive a simulated outdoor season before tooling is locked.
- John Smith, Senior Application Engineer, Shanyo Precision Electronics, Qingdao
