When Gaskets
Fail,
Motorsil D
Steps In
How Arexons Motorsil D RTV Silicone Sealant keeps turbines, compressors, and rotating equipment running — where ideal conditions don't exist.
Ideal Conditions Don't Exist in the Field
In rotating equipment maintenance — gas turbine auxiliaries, lube oil systems, compressor bearing housings — the textbook assumption of perfectly flat, clean, dimensionally stable joint faces rarely holds true in practice.
Surfaces wear. Tolerances stack. Flanges warp under thermal cycling. After the third or fourth maintenance cycle, even a precision-machined cover starts showing micro-irregularities that let fluid find a path out. A conventional pre-formed gasket can only do so much when the substrate itself is no longer nominal.
This is the gap that Arexons Motorsil D is specifically engineered to fill — not as a workaround, but as a deliberate maintenance tool for conditions where rigid sealing systems fall short.
Dimensional changes between hot and cold states open micro-gaps that rigid gaskets cannot track.
Repeated disassembly degrades seating faces, creating leak paths conventional gaskets can't address.
Continuous micro-movement in operating equipment progressively compromises static seal integrity.
Practical tolerances in heavy rotating equipment rarely match the clean assumptions of the design drawing.
Arexons Motorsil D · Original Silicone Gasket · −70°C to +300°C
What Motorsil D Actually Is
Arexons Motorsil D is an acetic cure RTV (Room Temperature Vulcanizing) silicone sealant — a compound that cures in the presence of atmospheric moisture to form a flexible, elastic polymer structure in place. Not a rigid adhesive. An in-situ elastic gasket that conforms to the joint geometry it's asked to seal.
The acetic cure system releases small amounts of acetic acid vapour during curing — a normal indicator that crosslinking is proceeding. Skin forms in approximately 10 minutes, with a cure rate of about 4.5 mm per 24 hours through depth. Controlled and predictable enough for planned maintenance windows.
Critically, the cured material exhibits no volume loss — it fills the joint geometry it's applied to and maintains that fill under load, unlike anaerobic or solvent-based sealants that can shrink and create re-leak conditions over time.
The value isn't in the chemistry alone. It's in how that cured compound behaves under real operating loads — thermal movement, vibration, oil exposure, and the accumulated imperfection of years in service.
The Numbers That Matter to Engineers
Here's what Motorsil D delivers post-cure and what those numbers mean in a maintenance context:
| Property | Value | Engineering Significance |
|---|---|---|
| Tensile Strength | ~4.5 MPa | Adequate for auxiliary flange and housing applications |
| Elongation at Break | ~200% | Absorbs thermal and vibrational movement without cracking |
| Shore A Hardness | ~50 | Firm enough to resist extrusion; flexible enough to conform |
| Compression Set | ~35% | Maintains sealing contact under sustained bolt load |
| Operating Temperature | −70°C to +250°C | Covers full range of turbine auxiliary environments |
| Peak Resistance | Up to +300°C | Short-duration thermal spikes handled without degradation |
| Skin Formation | ~10 min | Assembly can proceed within a tight maintenance window |
| Cure Rate (depth) | ~4.5 mm / 24 hr | Predictable through-cure for joint gap planning |
| Shelf Life | ~2 years | Suitable for MRO stock holding |
The 200% elongation combined with Shore A 50 hardness is the key pairing. The cured seal is not a brittle plug — it is a living gasket that stretches, compresses, and recovers across thermal and vibration cycles typical of rotating equipment auxiliaries. That continuous contact with both faces is what keeps the system sealed during operation.
Where Motorsil D Does Its Best Work
In a power plant or compressor installation, Motorsil D is applicable across multiple systems — wherever metal-to-metal joints are subject to real operating conditions. Hover each card to explore.
- Bearing housing covers
- Exciter housings
- Slip ring enclosure covers
- Terminal box covers
- Turbine bearing housings
- Turning gear housings
- Auxiliary gearbox housings
- Bearing pedestal joints
- Lube oil pump housings
- Oil cooler covers
- Oil filter housings
- Seal oil auxiliary covers
- Cooling water pump casings
- Heat exchanger covers
- PHE inspection ports
- Coolant manifold joints
- Replacement of pre-formed gaskets
- Metal-to-metal flange sealing
- Vibration-prone auxiliary joints
- Emergency in-situ gasket forming
- Auxiliary skid junction covers
- Intercooler housing joints
- Pulsation dampener flanges
- Inlet filter housing seals
Know When Not to Reach for the Tube
Part of using any maintenance product correctly is understanding its limits. Motorsil D is not a universal solution — applying it outside its scope creates problems rather than solving them.
Not for precision-machined joints requiring rigid gasket control. Where OEM specifications call for dimensionally controlled gaskets with defined compression, RTV sealants cannot replicate that behaviour. Dimensional control is lost once you form the seal in-situ.
Not for structural sealing under high pressure without mechanical support. Motorsil D requires mechanical retention — bolt load and joint geometry — to function. It is not a standalone pressure boundary component.
Not a substitute for OEM-specified sealing systems. In warranty situations or mandated repair procedures, confirm whether RTV use is permitted before application. Deviation may carry contractual implications.
Used where it belongs, it performs reliably across multiple thermal cycles. Used outside its scope, it creates accountability issues. Its honest positioning — as a maintenance aid for real-world conditions, not a replacement for precision engineering — is exactly what makes it a durable part of any maintenance programme.
Handling Essentials
Motorsil D follows standard RTV silicone handling protocols. The acetic cure mechanism releases low concentrations of acetic acid vapour during curing — ensure adequate ventilation in enclosed spaces. Avoid eye and skin contact; standard chemical handling PPE applies.
The approximately 2-year shelf life makes it a practical MRO stock item. Keep sealed, away from moisture and direct sunlight. Check the batch date before use — degraded product shows altered consistency and extended skin formation times.
| Requirement | Guidance |
|---|---|
| Eye Protection | Safety glasses / face shield |
| Hand Protection | Chemical-resistant gloves |
| Ventilation | Adequate airflow during cure |
| Storage | Sealed, cool, dry location |
| Shelf Life | ~2 years from manufacture |
Technical Solutions · Industrial Sealing
Need Motorsil D
for Your Plant?
TechMRO Inc supplies industrial sealing and maintenance materials to power plants, compressor stations, and rotating equipment operations across India.