Polysulfide products in the sources
Where to buy| Product | Maker | Form and class | Life and cure (from the source) | Specification stated |
|---|---|---|---|---|
| PR-1422 Class B | PPG | Two-part; B-1/2 and B-2 | B-1/2: life 1/2 h, tack-free under 8 h, 35 A in 24 h. B-2: life 2 h, under 20 h, 36 h (77 F, 50 % RH) | Tests per AMS-S-8802 Class B |
| PR-1440 Class B | PPG | Two-part; B-1/2, B-2 | Distributors list about 30 min (B-1/2) and 2 h (B-2); their tack-free and cure times disagree, so none is given | AMS-S-8802D Type 2 (distributor) |
| PS-890 | PPG | Two-part, manganese dioxide cured; Classes A, B, C | Distributor lists A-2 at 2 h, B-4 at 4 h, C-80 at 80 h | AMS-S-8802, BMS 5-45 (distributor) |
| PR-1776M Class B | PPG | Two-part, manganese dioxide cured, Permapol P-5 modified polysulfide (PPG's wording) | B-1/2, B-2 grades | AMS 3281 Type 1 Class B-2; BMS 5-45 |
| CS 3201 | Flamemaster | Two-part polysulfide; Class A brush, Class B gun | Application life halves for every 10 F rise and doubles for every 10 F drop | Not stated in the part we read |
Sources: PPG PR-1422 sheet (09/10); distributor listings for PS-890 and PR-1440; PPG PR-1776M page; Flamemaster CS 3201 bulletin. Distributor lists are not PPG data sheets.
What polysulfide sealant is
A polysulfide sealant is a two-part synthetic rubber: a base and a curing agent are mixed and cure at room temperature to a flexible rubber. The Flamemaster bulletin describes CS 3201 that way, with excellent adhesion to aluminium, titanium, stainless steel, steel and magnesium, resistance to aircraft fuels, lubricants, oils and water, and flexibility at low temperatures. Polysulfides are the long-standing fuel tank and fuselage sealants, and the one most structural repair manuals name.
Classes A (brush), B (fillet) and C (faying) are explained in the sealant types guide. The number after the class is the application life in hours.
PR-1422 Class B
What it is. A two-part fuel tank fillet sealant from PPG (data sheet issue 09/10).
What it is for. Fillet seals, vertical and overhead seams; also other fuselage sealing (PPG sheet).
How it is used. Mix the parts in the kit ratio, apply with a gun or spatula at about 30 degrees off perpendicular (application bulletin).
Life and cure. See the table: B-1/2 and B-2. Kits keep at least 9 months between 40 and 80 F. Service range -65 to 250 F, brief excursions to 275 F.
Safety. SDS and AC 43.13-1B par. 6-90.
Specification. Tests per AMS-S-8802 Class B (PPG).
Equivalents. PR-1440 and PS-890 are other PPG sealants of the same kind; the SRM names which one.
PR-1440 Class B
What it is. A PPG two-part Class B fuel tank sealant (distributor listings).
What it is for. Integral fuel tank sealing.
How it is used. Per the PPG data sheet.
Life and cure. Distributors list B-1/2 at about 30 minutes and B-2 at about 2 hours; they disagree on tack-free and cure times, so read PPG's current sheet. A full cure at 77 F and 50 % RH is listed as 14 days by distributors.
Safety. SDS.
Specification. Listed as AMS-S-8802D Type 2 by distributors.
Equivalents. Not by dash number alone; the SRM names the sealant.
PS-890
What it is. A two-part manganese dioxide cured polysulfide, available in Classes A, B and C (distributor listing).
What it is for. Aircraft fuel tank sealing.
How it is used. Per the PPG data sheet.
Life and cure. The distributor lists A-2 at 2 hours, B-4 at 4 hours and C-80 at 80 hours of application life. Service range -65 to 250 F, brief excursions to 275 F.
Safety. SDS.
Specification. AMS-S-8802 and BMS 5-45 are the specifications the listings cite.
Equivalents. Equivalence is by specification and QPL, not by name.
Chem Seal CS 3201
What it is. A two-part polysulfide from Flamemaster, Class A brush and Class B gun (bulletin).
What it is for. Sealing aluminium, titanium, steel and magnesium joints.
How it is used. Clean the surface, mix 10 parts of the curing agent into 100 parts of base by weight, stir until uniformly tan with no white or black streaks. Do not thin. Avoid high-speed mixing, which shortens life and traps air.
Life and cure. Application life at 77 F and 50 % RH; each 10 F rise halves it and each 10 F drop doubles it. Nonvolatile content is 90 % for Class A and 98 % for Class B; Shore A hardness is 30 to 45 and 30 to 50.
Safety. SDS.
Specification. Not stated in the part we read.
Equivalents. Not by name.
Questions people actually ask
Is PR-1422 a polysulfide?
The data sheets we read do not state the polymer. The sealant types guide and the SRM treat it as a two-part synthetic rubber fuel tank sealant.
Does heat shorten the life?
Yes. Flamemaster's rule for CS 3201 is a halving for every 10 F rise; the same pattern holds for other two-part sealants but check each sheet.
What does B-2 mean?
Class B with 2 hours application life at the test conditions.
Limits — when NOT to use this
What the sources support, and no further.
- Distributor lists for PR-1440 and PS-890: they are not PPG data sheets.
- No cross-reference table is authoritative. The SRM and the specification's QPL decide equivalents.
- Specifications are cited as the sources print them. AMS-S-8802 text is paid and was not read.
Where to buy
Distributors coming soon.
Sources
- PPG Aerospace, PR-1422 Class B Fuel Tank Sealant, data sheet (issue 09/10, Lit 0157) — Application life, tack-free, cure, slump, service range, storage; tests per AMS-S-8802 Class B.
- Flamemaster Corporation, Chem Seal CS 3201 Technical Bulletin — Two-part polysulfide: classes A and B, mixing, temperature effect on application life, hardness, adhesion.
- PPG PS890 B-1/2 Fuel Tank Sealant (distributor listing) — Two-part manganese dioxide cured polysulfide, service range, classes. Distributor listing, not the PPG data sheet.
- PPG PR-1440 B-1/2 Fuel Tank Sealant (distributor listing) — AMS-S-8802D Type 2 designation. Distributor listing, not the PPG data sheet.
- 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.
- Sealant application bulletin: class and applications (distributor document) — Class A brush, B fillet, C rollable.
- SAE International, AS5127/1C: Test Methods for Aerospace Sealants, Two-Component Synthetic Rubber Compounds — Scope: test methods for two-component sealing compounds.