Aircraft Fuel Tank Sealant: Types, Uses and Buying Guide
Aircraft fuel tank sealant is a fuel-resistant material used to seal joints, seams and fasteners in an aircraft’s integral fuel tank. The correct choice depends on the approved maintenance instructions, where the sealant will be applied, the required application method and the exact material identifier.
Key Takeaways
- Integral fuel tanks use sealed aircraft structure to contain fuel.
- Class A and Class B identify application classes; they are not interchangeable purchasing descriptions.
- Specify the complete part number, including its suffix, when requesting a quote.
- Compare the intended location, application method and packaging before ordering.
Where Fuel Tank Sealant Is Used
In an integral fuel tank, portions of the aircraft structure form the tank boundary. Sealant helps close potential leak paths at structural joints, seams, fasteners and other specified details. Tank sealing may involve different operations: coating a defined area, sealing around a fastener, or forming a bead along a joint. Those tasks can call for different material classes and application characteristics.
Fuel resistance alone does not make every aircraft sealant suitable for every tank detail. A material described for tank fillets, for example, answers a different application need from one selected for a fastener-sealing operation. For a broader view of how sealants are grouped by use, see CraftJetAero’s guide to types of aircraft sealant.
Class A and Class B: What Buyers Need to Distinguish
Class designation is a useful first filter, but it is not a complete material selection. The product examples here illustrate why: P/S 890 Class A is identified as an integral fuel tank sealant, while PR-1750 Class B and PR-2001 Class B are specifically described for fillet sealing. The class, product designation and intended repair or production task should all agree with the purchase requirement.
| Example | Source-described type | Relevant application detail |
|---|---|---|
| P/S 890 Class A, PN PS890A-2 | Integral fuel tank sealant | A Class A option identified for fuel tank use |
| PR-1782 Class A, PN PR1782A-2 | Low-density fuel tank and general-purpose sealant | Described for sealing fasteners in fuel tanks and fuselages |
| PR-1750 Class B, PN PR1750B-1/2 | Two-part polysulfide fuel tank sealant | Low-sag paste described for tank fillet sealing |
| PR-2001 Class B, PN PR2001B-1/2 | Two-part polythioether sealant | Low-sag paste described for tank fillet sealing |
This comparison identifies stated uses, not substitutes. Even two Class B products can differ in chemistry and other properties. For example, the listed PR-1750 Class B material is a manganese dioxide-cured polysulfide, whereas PR-2001 Class B is an epoxy-cured polythioether. The application requirement determines whether either is appropriate.
How to Compare Candidate Materials
Start with the location and sealing operation, then compare only the characteristics relevant to that job. A practical review can follow this order:
- Identify the tank detail. State whether the task concerns a specified joint, fillet, fastener or another defined area.
- Match the application form. A low-sag paste intended for extrusion or spatula application may fit a fillet operation; do not assume it fits a different sealing process.
- Confirm the complete designation. Record the brand, product family, class and full part number rather than ordering by the words “fuel tank sealant” alone.
- Check the required pack format. State any kit size or packaging requirement separately from the material identifier.
- Review the stated operating conditions. Compare documented service-temperature and fuel-exposure information where those factors matter to the application.
For example, the listed PR1750B-1/2 Class B fuel tank sealant is described as a low-sag paste for fillet sealing, suitable for application by extrusion gun or spatula. The listed PR2001B-1/2 polythioether sealant is also described as a low-sag Class B material for fillets, but it belongs to a different chemical family. That distinction is a reason to verify the specified material, not to substitute one based on a similar use description.
Writing an Unambiguous Purchase Request
A good request separates the required item from helpful context. It gives the seller an exact identifier to quote while making clear which details still need confirmation by the buyer. If the maintenance paperwork names a particular part number, copying that entire designation reduces the risk of confusing nearby variants.
For example: “Please quote PPG Aerospace PR1750B-1/2 aircraft fuel tank sealant. The application is an integral-tank fillet. Please identify the offered packaging and provide the product documentation associated with the quoted item.” This wording does not ask the supplier to choose a replacement material. If the buyer has an approved packaging requirement, quantity or documentation requirement, those can be added explicitly.
- Material identity: manufacturer, product name or series, class and complete part number.
- Order details: requested quantity and required packaging, if specified.
- Receiving needs: any documentation the purchasing organization requires with the shipment.
- Application context: enough information to flag a potential mismatch without treating a quote as an engineering approval.
Check punctuation in identifiers carefully. In the examples above, PR1750B-1/2 and PR2001B-1/2 are different products, despite sharing a Class B designation and a “-1/2” ending. The suffix alone is not a reliable way to identify a sealant or infer its properties.
Application and Receiving Checks
Before material is issued to a job, the maintenance and materials teams can check that the received label matches the requested part number and packaging. They can also confirm that required product documents are available and that the material is routed to the correct work order. These checks help prevent an otherwise plausible sealant from reaching the wrong application.
For two-part products, preparation and application are separate decisions from purchasing. The team needs the instructions for the exact material and package supplied, including how it is prepared and applied. A description such as “rapid cure” should not be used to calculate a work window or return-to-service time; those decisions require the applicable product instructions and maintenance requirements.
Use only the material and process authorized by the applicable aircraft maintenance documentation and approvals; follow the manufacturer’s current data sheet for preparation, application and handling. A product listing or supplier quote does not establish interchangeability or airworthiness.
Sourcing from CraftJetAero
CraftJetAero lists aircraft fuel tank sealants among its aviation chemicals. Buyers can request a quote by part number and include the required packaging, quantity and documentation details in the inquiry.
Frequently Asked Questions
What is aircraft fuel tank sealant used for?
It is used to seal specified potential leak paths in aircraft fuel tanks, including certain joints, seams and fastener details. The exact material and placement depend on the aircraft and the maintenance task.
Are Class A and Class B fuel tank sealants interchangeable?
No interchangeability follows from the class names alone. The required product designation, application and approved instructions must be checked for the specific job.
Is every fuel-resistant sealant suitable for an integral tank?
No. Fuel resistance is one characteristic; the intended sealing operation, material identity and applicable maintenance requirements also matter.
What should a buyer include in a fuel tank sealant RFQ?
Include the manufacturer and complete part number, plus the requested quantity, packaging and documentation requirements. Stating the intended sealing task can help clarify the inquiry.
Can two Class B sealants have different chemistries?
Yes. The listed PR-1750 Class B product is a polysulfide compound, while the listed PR-2001 Class B product is a polythioether compound.