What polythioether sealant is
Where to buyPolythioether is another family of two-component fuel-resistant sealant rubber, used where lower weight or different temperature behaviour is wanted. The SAE test standard AS5127/1 covers two-component aerospace sealants in general, and sealant removers are sold for polysulfide, polythioether, silicone and RTV alike (distributor listing).
We could not find a polythioether manufacturer data sheet we could read in full, so we give no cure, life or temperature figures. The existing sealant types guide says the same.
Names that cause confusion
PPG calls PR-1776M Class B a manganese dioxide cured "Permapol P-5 modified polysulfide"; distributor listings give AMS 3281 Type 1 Class B-2 and BMS 5-45. Labels such as polysulfide, polythioether and low-weight overlap in marketing. The sealant's specification and the SRM, not the label, decide what may replace it.
How to identify the type
| Where to look | What it tells you |
|---|---|
| Data sheet, product description | The chemistry the maker states |
| Specification line (AMS-S-8802, AMS 3281, BMS 5-45 and so on) | The qualified class and type |
| SRM or AMM material list | The sealant allowed on this aircraft |
Questions people actually ask
Is polythioether better than polysulfide?
We found no neutral data to compare. Choose by the SRM.
Can I mix polythioether and polysulfide on one joint?
Only if the SRM allows. Sealants can fail to adhere to each other; follow the manual's removal and recoat rules.
Are the removers the same?
Distributor listings say one remover family works on both; confirm with the AMM.
Limits — when NOT to use this
What the sources support, and no further.
- No polythioether data sheet read. No figures are given.
- The only named product here is PR-1776M, and PPG calls it a modified polysulfide.
Where to buy
Distributors coming soon.
Sources
- PPG Aerospace, PR-1776M Class B Low Weight Fuel Tank Sealant (product page) — Described by PPG as a manganese dioxide cured Permapol P-5 modified polysulfide; service range.
- PPG PR1776M B-2 Low Weight Fuel Tank Sealant (distributor listing) — AMS 3281 Type 1 Class B-2 and BMS 5-45 Class B-2.
- SAE International, AS5127/1C: Test Methods for Aerospace Sealants, Two-Component Synthetic Rubber Compounds — Scope: test methods for two-component sealing compounds.
- Socomore, SkyRestore Cured Sealant Remover, Technical Data Sheet (distributor copy) — Liquid 306 and gel 307 removers for polysulfide, polythioether, silicone and RTV sealants.