A nonround enclosure does not automatically need a one-piece molded gasket to meet an IP67 requirement. Adhesive-spliced cord, vulcanized-spliced rings and molded gaskets can each work when the complete enclosure is properly designed and tested. Choose between them by joint consistency, compression control, flange stiffness and expected opening cycles—not shape alone.
Our enclosure ratings are manufacturer ratings for the specified design; our enclosures are not UL listed. Any requested IP67 performance needs confirmation for the completed configuration, including its gasket, fasteners, penetrations and installed components.
How the three constructions compare
The distinction is how the closed sealing loop is manufactured. It does not determine the elastomer, cross-section or required compression.
| Selection point | Adhesive-spliced cord | Vulcanized-spliced ring | One-piece molded gasket |
|---|---|---|---|
| Closure joint | Cut ends joined with a compatible adhesive | Ends joined through a controlled vulcanizing process | No cord closure splice |
| Main advantage | Flexible perimeter changes without dedicated molding tooling | Repeatable closed loops without full-perimeter molding tooling | Repeatable shape, corners and locating features |
| Main process risk | Poor fit, contamination, incompatible adhesive or excess adhesive | Misalignment, local section variation or an unsuitable joining process | Flash, molding defects, dimensional variation or unsuitable compound |
| Compression requirement | Supplier-defined, including the joint | Supplier-defined, including the joint | Supplier-defined for the molded section |
| Repeated opening | Joint and retention need particular attention | Joint still needs cycle validation | Retention and compression set still need validation |
| Nonround perimeter | Feasible with suitable corner radii and retention | Feasible with suitable corner radii and retention | Can incorporate a dedicated nonround outline |
| Basis for acceptance | Qualified splice process and assembled testing | Qualified joint process and assembled testing | Qualified molded part and assembled testing |
Compare constructions using the same environmental requirements and an appropriate cross-section. Otherwise, a material or geometry difference can be mistaken for a joint difference.
The foam versus rubber door gasket comparison covers the separate question of cellular versus solid sealing materials. Neither material category automatically selects the best manufacturing method.
Where adhesive-spliced cord makes sense
Adhesive-spliced cord suits development work and changing enclosure perimeters when a qualified joining process is available. Cutting cord to length avoids committing immediately to dedicated molding tooling.
The joint must do more than stay connected during installation. Its shape must remain within the sealing section's dimensional limits after bonding. A gap, offset or raised adhesive bead can create uneven contact even when the ring looks continuous.
Specify the adhesive and surface preparation for the exact elastomer. A general-purpose adhesive is not automatically suitable for water exposure, cleaning chemicals, temperature cycling or repeated flexing.
For repeatable production, define:
- Cord material, hardness and cross-section tolerances.
- Cut geometry and permitted end alignment.
- Approved adhesive, preparation and curing process.
- Joint inspection and mechanical acceptance criteria.
- Traceability between the finished loop and its manufacturing batch.
An adhesive splice is not automatically unsuitable for immersion protection. However, an unqualified hand-made joint is a poor basis for claiming consistent enclosure performance.
Where a vulcanized-spliced ring wins
A vulcanized-spliced ring is useful when you want a factory-made closed loop without tooling for the entire gasket outline. It can be a practical choice for larger perimeters or several related enclosure sizes.
The joining process uses controlled conditions and a compatible material system to form the splice. Ask for the finished joint's dimensional and mechanical limits, rather than accepting the word “vulcanized” as a performance specification.
A vulcanized splice is still a joint. Local hardness, section size, alignment and strength can differ from the parent cord. Those differences matter when the splice crosses a region with limited compression or significant movement during opening.
Request samples made by the intended production process. Check the joint both before installation and after representative opening, environmental exposure and sealing tests.
This construction is a strong candidate when a bonded cord loop lacks sufficient process consistency, but a dedicated molded outline adds little functional benefit.
Where a one-piece molded gasket wins
A molded gasket removes the cord closure splice and can incorporate a repeatable nonround outline. It is particularly useful when the design needs corner transitions, retention tabs or changes in cross-section.
Those features can reduce installation variation. A shaped gasket may be easier to locate correctly than a long cord loop that twists or stretches during assembly.
Molding does not remove every leak mechanism. Parting lines, flash, surface defects and dimensional variation still need acceptance limits. The compound must also provide suitable compression behavior and environmental resistance.
Choose molding when its geometry or assembly consistency solves a real problem. Do not expect it to correct a flexible lid, excessive fastener spacing or an incorrectly controlled sealing gap.
For the interface itself, use the tongue and groove gasket design article. Keep the manufacturing decision separate from the groove and retention design.
Compression and flange stiffness decide whether it seals
Get compression limits from the gasket supplier for the exact material, hardness and section. There is no universal squeeze percentage covering solid cord, sponge profiles and molded sealing lips.
For a simple solid section compressed between opposing surfaces, nominal compression is:
Compression (%) = (free gasket height − closed sealing gap) / free gasket height × 100
For example, a 0.160 in [4.06 mm] section closed to a 0.120 in [3.05 mm] gap has 25% nominal compression. This calculation illustrates the method; it is not a recommended compression target.
Calculate the limits using actual tolerances. Minimum compression combines the smallest gasket section with the largest local closed gap. Maximum compression combines the largest section with the smallest local gap.
Include groove depth, flange flatness, lid deflection and any variation at the splice. Average compression around the perimeter cannot compensate for one under-compressed location.
Use supplier load-deflection data to estimate closure force. Then check whether the flange and fastener arrangement can maintain the required gap between clamping points. Torque alone does not demonstrate uniform compression.
A thin housing can bow under gasket reaction force or pressure differential. The large thin-walled lid sealing article addresses that structural problem. Switching to a molded gasket will not stiffen the lid.
Repeated opening changes the choice
Define how often the enclosure will open before choosing the construction. A cover opened only during assembly presents a different duty from a door opened during routine maintenance.
Opening can pull a poorly retained gasket from its groove. Reinstallation can twist cord, stretch the loop or bend the splice. Dirt and trapped wiring can interrupt the sealing line regardless of construction.
Set a representative opening-cycle requirement based on the intended service life. Include the actual removal, cleaning and closing procedure, not just repeated fastener operation.
Inspect for:
- Joint separation, cracking or local distortion.
- Permanent flattening and loss of recovery.
- Stretching, rolling or displacement from the sealing path.
- Damage caused by retention features or cover removal.
A molded gasket with suitable retention may simplify repeated assembly. A qualified spliced ring can also work when handling and retention keep damaging loads away from the joint.
The raised-lip versus flat-face gasket article explains another interface choice that affects location and contact. Validate that interface with the selected gasket construction.
Test the completed enclosure, not just the gasket
IP67 under IEC 60529 combines dust-tight protection with temporary immersion protection under specified test conditions. It is not a material designation or a certificate supplied by the gasket alone.
Agree on the applicable test conditions and acceptance criteria before approving the design. Include enclosure orientation, assembly procedure and any conditioning required by the product specification.
For a useful validation sequence:
- Record gasket dimensions, joint position, fastener arrangement and assembly settings.
- Check the closed gap and contact consistency around the full perimeter.
- Perform the agreed dust and immersion evaluations on representative assemblies.
- Repeat the relevant sealing evaluation after specified opening cycles and environmental conditioning.
- Inspect the interior using a defined procedure that prevents opening water from confusing the result.
The enclosure water-ingress inspection procedure covers that final distinction. Water carried inside during opening can otherwise be mistaken for a sealing failure.
Document the tested configuration. Cable entries, vents, windows and mounting penetrations are separate leak paths, and each needs inclusion in the assessment. A component's individual rating does not establish the completed enclosure's rating.
Choose by exposure and service duty
For temporary immersion with infrequent opening, all three constructions remain candidates. Favor the option with controlled dimensions, documented joining or molding processes, and successful assembled testing.
For frequent access, prioritize retention, recovery and repeatable installation. A one-piece molded outline may reduce handling errors, while a qualified vulcanized ring may provide sufficient consistency without dedicated perimeter tooling.
For changing dimensions or early design iterations, adhesive-spliced cord can simplify changes. Keep the final production joint process within the qualification plan rather than treating the prototype as proof.
For chemical cleaning, verify the compound and any joining materials against the actual chemical, concentration, temperature and contact time. Immersion testing alone does not establish sanitizer compatibility or corrosion resistance.
For temperature cycling, include both material behavior and enclosure pressure changes. If a pressure-equalizing vent is proposed, validate it as part of the complete assembly. It does not replace the perimeter seal.
What to specify on the drawing and order
Send the sealing requirement with the enclosure layout, not after the body dimensions are fixed. Our custom enclosure options let you define material, width, height, depth and every cutout from one piece.
For an existing stainless body or a revised opening layout, the custom stainless enclosure and cutout page explains the drawing-based review. New openings do not automatically preserve the original rating.
| Drawing or order field | Information to provide |
|---|---|
| Required protection | IP67 requirement, applicable standard and agreed completed-assembly evaluation |
| Gasket construction | Adhesive-spliced cord, vulcanized-spliced ring or one-piece molded gasket |
| Gasket definition | Compound, hardness, section dimensions and tolerances |
| Joint requirements | Process, location, dimensional limits and inspection criteria, where applicable |
| Compression control | Supplier-approved range, closed gap, tolerances and any stops |
| Flange and closure | Flatness limits, fastener or latch positions, and assembly settings |
| Service duty | Expected opening cycles, cleaning method and replacement criteria |
| Environmental exposure | Water conditions, temperature range and chemical exposure |
| Complete configuration | All entries, vents, windows, mounting details and sealing components |
| Acceptance records | Approved drawing revision, test configuration and inspection results |
Select the construction that produces a controlled sealing loop in your actual assembly. A sound joint can seal reliably; a joint-free gasket cannot rescue an uncontrolled flange.
Enclosures for this job
Catalog sizes that suit the job this article answers, picked from its subject; open one for its full specifications.
| Enclosure | Material | Outside H x W x D / display | Rating |
|---|---|---|---|
| 12 × 10 × 6 in | 304 stainless | 12 x 10 x 6 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 16 × 14 × 8 in | 304 stainless | 16 x 14 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 20 × 16 × 8 in | 304 stainless | 20 x 16 x 8 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
Questions
Does a nonround enclosure need a molded gasket for IP67?
No. A flexible cord loop can follow a nonround perimeter when corner radii, retention and compression are suitable. Choose a molded outline when its geometry or installation consistency provides a useful advantage. The completed enclosure still needs evaluation against the specified protection requirement.
Can an adhesive-spliced gasket meet an IP67 requirement?
Yes, a qualified adhesive-spliced gasket can be part of an enclosure that meets an IP67 requirement. Acceptance depends on the exact elastomer, adhesive, joint geometry, assembly and exposure. A successful gasket joint alone does not establish the protection rating of the completed enclosure.
Is a vulcanized-spliced ring the same as a one-piece molded gasket?
No. Vulcanizing joins the ends through a controlled process, but the finished ring still contains a joint. Its dimensions, alignment and mechanical properties need defined limits. A one-piece molded gasket has no cord closure splice, although molding defects and dimensional variation still require inspection.
What compression percentage should an enclosure gasket use?
Use the supplier's approved range for the exact material, hardness and cross-section. Calculate minimum and maximum compression from gasket and enclosure tolerances, including flange deflection. A single nominal percentage cannot establish suitability across solid cord, sponge profiles and molded sealing lips.
Will replacing a spliced gasket with a molded gasket stop leaks?
Not by itself. The new gasket may change closure force, compression and assembly behavior. Check the sealing gap and flange response, then evaluate representative completed assemblies under the agreed conditions. Include opening cycles and environmental conditioning when those exposures are part of the service requirement.
