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The Aviation PointTechnical data sheet · theaviationpoint.com/parts/materials/pr-812/

PR-812 — firewall sealant

Aerospace sealant is sold in two parts as a class and a dash number. The class says how it is applied and where: A by brush, B as a fillet, C between mating faces. The dash number, as in B-2, is the application life in hours: how long the mixed sealant stays usable. The product itself, and its class and dash number, are named in the SRM; this guide explains the system so the sheet reads clearly.

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PR-812 at a glance

Where to buy
PR-812 schematic
Schematic

Designation

ItemValue
DesignationPR-812
ClassSealants
Typefirewall sealant

In stock

Distributor sheetListed
PR812 Firewall SealantTo 204 °C · 1093 °C flash

As distributors list them, not a statement of what a specification allows.

As listed by the sellers

ItemValue
TypeTwo-part synthetic rubber
UseSealing firewall structures against air and vapour
Service temperature-54 °C to 204 °C; flash to 1093 °C
FormLow-sag paste, gun or spatula

The seller's statements, not a qualification.

Notes from the guide

  • The manual governs. The SRM names the sealant, class, dash number and primer.
  • One product sheet. The dash table is PR-1422 Class B. We have not read the data for Class A or C of any product, and we give none.
  • No viscosity ranges. The sources do not agree on them.

Where to buy

AmericaDistributor coming soonOur partner for this region is on its way
EuropeDistributor coming soonOur partner for this region is on its way
OceaniaDistributor coming soonOur partner for this region is on its way

Distributors coming soon.

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Calculators

CalculatorSealant Fillet & CartridgesHow much sealant a fillet seam takes and how many cartridges to mixCalculatorPot Life TimerA pot life timer for mixed sealant, resin or adhesiveCalculatorTwo-Part Mix Ratio CalculatorBatch a two- or three-part product by volume or weightCalculatorAluminum Sheet Weight CalculatorAluminum sheet weight per square foot and per piece, from MIL-HDBK-5 densities, and the moment…

Guides

GuideSealant typesThe guide to PR-812.GuideFay and fillet sealingWhere a metal repair is sealedGuidePolysulfide sealantsPolysulfide aircraft sealants comparedGuidePolythioether sealantsPolythioether aircraft sealant explained

Data sheets

Data sheetMaterialsEvery material data sheet.Data sheetDOWSIL 732silicone sealantData sheetRTV3145silicone sealantData sheetPS-890polysulfide sealant

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Distributors coming soon.

Sources

  • PPG Aerospace, PR-1422 Class B Fuel Tank Sealant, data sheet (issue date 09/10, Lit 0157) — Description, service temperature, mixing ratio, application life, tack-free and cure table, slump, storage life; tests per AMS-S-8802 Class B.
  • Sealant application bulletin: class and applications (distributor document) — Class A brush, B fillet, C rollable; brush application; gun angle and direction of travel.
  • SAE International, AS5127/1C: Test Methods for Aerospace Sealants, Two-Component Synthetic Rubber Compounds — Scope: test methods for two-component sealing compounds, used with AS5127 and the material specification; revision history to AS5127/1D (2020).
  • FAA AC 43.13-1B CHG 1, Chapter 6 — Pars. 6-50h, 6-50i and 6-150, non-corrosive sealant and drains; see the sealing guide.
  • Distributor listings — stock forms, sizes and listed facts, read 30 September 2026.
Educational reference only. not approved data. Always consult the applicable SRM, AMM, or AC 43.13-1B and your certifying authority.
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