Cork thermal protection (Amorim P45/P50, SLA-561 heritage)

spore: profile
id: cork-ablator
spore_version: 0.2
family: cork
name: Cork thermal protection (Amorim P45/P50, SLA-561 heritage)
role: ablator and insulator
category: living
type: bio-grown-building-materials
summary: Cork thermal protection is a sheet ablator and insulator made from cork particles. Amorim's typical density at 20 °C is 304 to 336 Kg/m3 for its P45 grade and 448 to 512 Kg/m3 for P50, and its thermal conductivity is 0.06 W/m•K for P45 and 0.07 W/m•K for P50. NASA's 1985 Space Shuttle booster report says bonded cork was the first candidate and was then flown on the aft skirt, where the predicted heating was above the range of the sprayable ablator MSA-I.
best_for: Low-density insulation and char-forming ablation on metal or composite structures where bonded cork can be applied (Amorim P45 and P50).
weakest_at: 'Tensile strength (above 0.86 MPa for P45) and refurbishment: bonded cork was labour intensive to apply, and its adhesive was extremely difficult to remove (NASA 1985).'
identity:
  formula: Sheets of cork particles from the bark of the cork oak (Quercus suber), sold as Amorim P45 and P50
  source: wiki-cork
  where: Introductory composition paragraph (Wikipedia); sheet and particle data from the Amorim TPS table
  composition: Suberin about 40%, lignin 22%, polysaccharides 18%, extractables 15% (Wikipedia, cork in general; no figure for other constituents)
  designations:
    - system: Trade name
      code: P45
      source: amorim-aerospace
      where: TPS Materials & Properties table, column header
    - system: Trade name
      code: P50
      source: amorim-aerospace
      where: TPS Materials & Properties table, column header
tags:
  environments:
    - re-entry
    - launch
  stresses:
    - extreme-heat
  applications:
    - heat-shields
    - propulsion-and-tanks
properties:
  - benchmark: density
    label: Density of P45 (metric table)
    value: 304
    value_high: 336
    bound: range
    unit: Kg/m3
    scope: material
    conditions:
      product: P45
      temperature: 20 °C
      test_standard: ASTM F1315 (table footnote 1)
    method: Typical value printed in the manufacturer's metric table; the table says it is not a purchasing specification
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Density @ 20° C (Kg/m 3) (1)', column P45
  - benchmark: density
    label: Density of P50 (metric table)
    value: 448
    value_high: 512
    bound: range
    unit: Kg/m3
    scope: material
    conditions:
      product: P50
      temperature: 20 °C
      test_standard: ASTM F1315 (table footnote 1)
    method: Typical value printed in the manufacturer's metric table; the table says it is not a purchasing specification
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Density @ 20° C (Kg/m 3) (1)', column P50
  - benchmark: density
    label: Density of P45 (imperial table)
    value: 19
    value_high: 22
    bound: range
    unit: lb/ft3
    scope: material
    conditions:
      product: P45
      temperature: 20 °C
      test_standard: ASTM F1315 (table footnote 1)
    method: Typical value printed in the manufacturer's imperial table, same grade as the metric row
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Density @ 20° C (lb/ft 3) (1)', column P45
  - benchmark: density
    label: Density of P50 (imperial table)
    value: 28
    value_high: 32
    bound: range
    unit: lb/ft3
    scope: material
    conditions:
      product: P50
      temperature: 20 °C
      test_standard: ASTM F1315 (table footnote 1)
    method: Typical value printed in the manufacturer's imperial table, same grade as the metric row
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Density @ 20° C (lb/ft 3) (1)', column P50
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of P45 (metric table)
    value: 0.86
    bound: lower
    unit: MPa
    scope: material
    conditions:
      product: P45
      test_standard: ASTM F152, Method B (table footnote 2)
      printed_as: greater than 0.86 MPa
    method: Typical lower bound printed in the manufacturer's metric table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Tensile strength (MPa) (2)', column P45
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of P50 (metric table)
    value: 1.73
    bound: lower
    unit: MPa
    scope: material
    conditions:
      product: P50
      test_standard: ASTM F152, Method B (table footnote 2)
      printed_as: greater than 1.73 MPa
    method: Typical lower bound printed in the manufacturer's metric table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Tensile strength (MPa) (2)', column P50
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of P45 (imperial table)
    value: 125
    bound: lower
    unit: psi
    scope: material
    conditions:
      product: P45
      test_standard: ASTM F152, Method B (table footnote 2)
      printed_as: greater than 125 psi
    method: Typical lower bound printed in the manufacturer's imperial table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Tensile strength (psi) (2)', column P45
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of P50 (imperial table)
    value: 250
    bound: lower
    unit: psi
    scope: material
    conditions:
      product: P50
      test_standard: ASTM F152, Method B (table footnote 2)
      printed_as: greater than 250 psi
    method: Typical lower bound printed in the manufacturer's imperial table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Tensile strength (psi) (2)', column P50
  - benchmark: thermal_conductivity
    label: Thermal conductivity of P45 (metric table)
    value: 0.06
    unit: W/m•K
    scope: material
    conditions:
      product: P45
      test_standard: ASTM C177 (table footnote 3)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's metric table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Thermal conductivity (W/m•K) (3)', column P45
  - benchmark: thermal_conductivity
    label: Thermal conductivity of P50 (metric table)
    value: 0.07
    unit: W/m•K
    scope: material
    conditions:
      product: P50
      test_standard: ASTM C177 (table footnote 3)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's metric table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Thermal conductivity (W/m•K) (3)', column P50
  - benchmark: thermal_conductivity
    label: Thermal conductivity of P45 (imperial table)
    value: 0.45
    unit: (Btu•in)/(h•ft2°•F)
    scope: material
    conditions:
      product: P45
      test_standard: ASTM C177 (table footnote 3)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's imperial table, same grade as the metric row
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Thermal conductivity (Btu•in)/(h•ft2°•F)', column P45
  - benchmark: thermal_conductivity
    label: Thermal conductivity of P50 (imperial table)
    value: 0.5
    unit: (Btu•in)/(h•ft2°•F)
    scope: material
    conditions:
      product: P50
      test_standard: ASTM C177 (table footnote 3)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's imperial table, same grade as the metric row
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Thermal conductivity (Btu•in)/(h•ft2°•F)', column P50
  - benchmark: specific_heat
    label: Specific heat of P45 (metric table)
    value: 2.5
    unit: KJ/Kg/°K
    scope: material
    conditions:
      product: P45
      test_standard: ASTM C351 (table footnote 4)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's metric table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Specific heat (KJ/Kg/°K) (4)', column P45
  - benchmark: specific_heat
    label: Specific heat of P50 (metric table)
    value: 2.1
    unit: KJ/Kg/°K
    scope: material
    conditions:
      product: P50
      test_standard: ASTM C351 (table footnote 4)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's metric table
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, metric, row 'Specific heat (KJ/Kg/°K) (4)', column P50
  - benchmark: specific_heat
    label: Specific heat of P45 (imperial table)
    value: 0.6
    unit: Btu/lb°•F
    scope: material
    conditions:
      product: P45
      test_standard: ASTM C351 (table footnote 4)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's imperial table, same grade as the metric row
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Specific heat (Btu/lb°•F) (4)', column P45
  - benchmark: specific_heat
    label: Specific heat of P50 (imperial table)
    value: 0.5
    unit: Btu/lb°•F
    scope: material
    conditions:
      product: P50
      test_standard: ASTM C351 (table footnote 4)
      temperature: not printed in the table
    method: Typical value printed in the manufacturer's imperial table, same grade as the metric row
    status: ground
    source: amorim-aerospace
    where: TPS Materials & Properties table, imperial, row 'Specific heat (Btu/lb°•F) (4)', column P50
  - benchmark: density
    label: Raw select cork, before formulation (1977 report)
    value: 3
    value_high: 3.5
    bound: range
    unit: lb/ft3
    scope: material
    conditions:
      material: select cork, raw, used in the report's formulations
      unit_as_printed: Ibs. per cubic foot
    method: Range stated in the report's background section, read from the scanned OCR text (pdftotext); not a product grade
    status: ground
    source: dodge1977
    where: Background, 'Why Cork?' section, paragraph beginning 'The properties which make cork a potential ablative insulating material'
corrosion:
  - environment: Liquid water and moisture
    headline: Closed cork cells resist liquid penetration, but the report gives no moisture-uptake test for the cork product.
    effect: The 1977 Dodge cork ablation report says cork has a very high resistance to moisture or liquid penetration because it has no interstices. It gives no test, exposure time or water-uptake figure for the cork product.
    rating: low
    conditions:
      basis: qualitative statement in the report background; no test
    source: dodge1977
    where: Background, paragraph beginning 'The unique structure of cork gives rise to unique properties'
  - environment: Re-entry or booster heating (ablation)
    headline: Amorim describes a char layer that protects the inner material; no ablation rate for P45 or P50 was found.
    effect: Amorim says its aerospace materials form a sturdy char layer that protects the inner material and slows thermal degradation. The page gives no ablation rate, char depth or recession value for either grade.
    rating: unknown
    conditions:
      basis: qualitative description on the manufacturer's aerospace page; no test conditions printed
    source: amorim-aerospace
    where: Aerospace page, section 'Ablative Thermal Protection Solutions for the Aerospace Industry'
risks:
  hazards:
    - text: The ComCORK safety data sheet says cork planks do not present any special risk and are not an explosion hazard, but sanding, sawing or machining can generate wood and cork dust that can present a strong explosion hazard if a dust cloud contacts an ignition source.
      ghs: []
      source: comcork-sds
      where: Section IV, Fire and Explosion Hazard Data, General
    - text: The same data sheet says both the skin and the respiratory system can become sensitized to wood dust, and that a sensitized worker can suffer a severe allergic reaction, such as asthma, after repeated exposure or exposure to lower concentrations of the dust.
      ghs: []
      source: comcork-sds
      where: Section VI, Health Hazard Data, item 1 (Wood Dust)
    - text: The same data sheet says ACGIH recognizes wood dust as a confirmed human carcinogen, and that OSHA regulates wood dust as a nuisance dust.
      ghs: []
      source: comcork-sds
      where: Section VI, Health Hazard Data, item 1 (Wood Dust)
  failure_risks:
    - mode: Adhesive-bonded cork is hard to remove for refurbishment
      trigger: Removing bonded cork from the metal structure during refurbishment studies
      consequence: NASA says the high-density cork, with its adhesive layer on the metal substrate, was extremely difficult to remove, and bonding was labour intensive. NASA then used a sprayable ablator (MSA-I) on the nose cap, frustum and forward skirt.
      severity: moderate
      source: srb1985
      where: Introduction, section 'TPS development challenge'
  side_effects: []
  handling:
    - text: Amorim says its products bond easily to most substrates using designated adhesive systems and can be precision-trimmed and machined to the required geometry.
      source: amorim-aerospace
      where: Aerospace page, introduction to the TPS Materials and Properties table
    - text: Amorim says its table gives typical values and is not intended as a purchasing specification.
      source: amorim-aerospace
      where: Note under the TPS Materials and Properties table
  mitigations:
    - text: NASA used the sprayable ablator MSA-I instead of bonded cork on the nose cap, frustum and forward skirt. It is sprayed by robot manipulator, not bonded.
      source: srb1985
      where: TPS development challenge; TPS system description
uses:
  - application: heat-shields
    device: Space Shuttle Solid Rocket Booster aft skirt
    example: NASA's 1985 report says cork insulation was flown on the aft skirt because the predicted thermal environments were considerably above the performance range of the sprayable ablator MSA-I, whose thickness was limited to 1/4 in.
    source: srb1985
    where: Conclusions paragraph near the end of the report; thermal design section on the aft skirt
  - application: heat-shields
    device: Re-entry probes
    example: Amorim says its TPS materials are qualified in several aerospace programmes for use as an ablative and thermal insulating heat shield in re-entry probes.
    source: amorim-aerospace
    where: Aerospace page, section 'Ablative Thermal Protection Solutions for the Aerospace Industry'
  - application: propulsion-and-tanks
    device: Rocket engines, cryogenic tanks and payload fairings
    example: Amorim lists solid rocket boosters, rocket engines, cryogenic tanks and payload fairings as thermal protection application areas across the launch. The page does not tie each area to a specific grade.
    source: amorim-aerospace
    where: Aerospace page, section 'Thermal protection across every stage of launch'
supply:
  - subject: Cork (bark of Quercus suber)
    producers:
      - country: Portugal
        share_percent: 49.6
    abundance: Not found in any source we hold.
    critical_lists: []
    recycling: Not found in any source we hold.
    substitutes: []
    note: Amorim quotes APCOR's 2018/19 yearbook for Portugal's share of world cork production (49.6%); the page prints no year for the figure. FAO gives Portugal about half of the world cork harvest (about 310,000 tons), with no year printed. No Spain share from APCOR was found in any source we hold.
    source: amorim-apcor-news
    where: 'Key statistics list in Amorim''s APCOR 2018/19 yearbook article: ''Portugal has 34% of the world''s cork oak forests (736,000 hectares) and produces 49.6% of world cork production.'''
gaps:
  - No flight record for cork in Viking or ESA QARMAN was read in this run. The Wikipedia cork article mentions a cork-based SLA-561V for Viking in a reference note; no NASA or Lockheed Martin source was opened, and the Amorim page names neither SLA-561 nor Viking.
  - No ESA QARMAN source was read. The web search budget for this run was used up before that search could run.
  - No maximum service temperature, ablation rate, char depth or recession rate for the P45 or P50 grades; Amorim gives none.
  - Density is printed only at 20 °C. No temperature dependence of thermal conductivity or specific heat is printed for P45 or P50.
  - No flexural, compressive or shear strength for the cork products; Amorim prints tensile strength only.
  - No water uptake, moisture ageing, UV or thermal ageing data found for cork products.
  - No bond strength to metal or composite. Amorim names no adhesive system, only 'designated adhesive systems'.
  - No safety data sheet or GHS classification was found for Amorim's P45 or P50. The hazard entries use a cork flooring data sheet (ComCORK, Sustainable Materials, prepared March 4, 2020), which is a different product, and state only what that sheet says. No GHS hazard statement is printed in it.
  - No dated producer shares. Amorim quotes Portugal at 49.6% of world cork production from APCOR's 2018/19 yearbook, and the page prints no year. FAO gives Portugal about half of the world cork harvest, with no year printed. No Spain share and no current USGS or FAO statistic were found.
  - The composition figures (suberin about 40%, lignin 22%, polysaccharides 18%, extractables 15%) are a Wikipedia average for cork in general, not measured on the Amorim product.
  - The 1977 report gives a K factor of 0.4 for compounds up to 35 pcf with 25 to 30% cork. It is not used here, because its unit is not printed in the scanned text.
  - The 1985 booster report prints density 15 to 17 lb/ft3 and thermal conductivity 0.48 to 0.6 Btu-in/ft2-hr-F for MSA-I, a sprayable epoxy-phenolic ablator, not for cork. These are not cork values; they appear only as a comparison in the story.
  - No UNS, EN or CAS code for cork as a material was found in the sources read. Only the Amorim trade names P45 and P50 are listed.
  - 'Media: no image of a cork thermal protection sheet was read and licensed for use in this run.'
sources:
  amorim-aerospace:
    title: 'Amorim Cork Solutions: aerospace thermal protection and TPS Materials and Properties table (P45, P50)'
    id: Amorim Cork Solutions aerospace materials page
    url: https://amorimcorksolutions.com/en-us/materials-applications/aerospace/
    kind: web
    license: Manufacturer web page, cited not reproduced
  srb1985:
    title: Thermal Design of the Space Shuttle Solid Rocket Booster (Fisher, Vaniman and Patterson, NASA Marshall Space Flight Center)
    id: NTRS 19850008667
    url: https://ntrs.nasa.gov/api/citations/19850008667/downloads/19850008667.pdf
    year: 1985
    kind: report
    license: public domain (NASA)
  dodge1977:
    title: Cork ablation final report, NASA CR-150382 (Dodge Cork Co., Inc., Lancaster, Pa.)
    id: NTRS 19770024370; N77-31314
    url: https://ntrs.nasa.gov/api/citations/19770024370/downloads/19770024370.pdf
    year: 1977
    kind: report
    license: public domain (NASA)
  wiki-cork:
    title: Cork (material), Wikipedia (read for composition and history only)
    id: 'Wikipedia article: Cork (material)'
    url: https://en.wikipedia.org/wiki/Cork_(material)
    kind: web
    license: CC BY-SA 4.0 (Wikipedia)
  wiki-cork-oak:
    title: Cork oak, Wikipedia (production share, no year given)
    id: 'Wikipedia article: Cork oak'
    url: https://en.wikipedia.org/wiki/Cork_oak
    kind: web
    license: CC BY-SA 4.0 (Wikipedia)
  comcork-sds:
    title: Material Safety Data Sheet (MSDS), ComCORK Flooring, Sustainable Materials LLC (date prepared March 4, 2020). A cork flooring product, not Amorim P45 or P50
    id: Sustainable Materials ComCORK Flooring MSDS
    url: https://www.sustainablematerials.com/wp-content/uploads/2026/03/ComCORK-MSDS-SM-2026.pdf
    year: 2020
    kind: datasheet
    license: Manufacturer SDS, cited not reproduced
  amorim-apcor-news:
    title: 'Amorim news: APCOR 2018/19 yearbook highlights (key statistics: Portugal 34% of cork oak forest, 49.6% of world cork production)'
    id: Amorim news, APCOR 2018/19 yearbook
    url: https://amorimcork.com/en/media-center/news/apcors-201819-yearbook-highlights-the-continuing-strong-export-growth-of-cork-stoppers/258
    kind: web
    license: Manufacturer web page, cited not reproduced
  fao-cork:
    title: 'FAO, Non-wood forest products, document x5362e, section 03 (cork): Portugal about half of the world cork harvest, about 310,000 tons, no year printed'
    id: FAO x5362e03
    url: https://www.fao.org/4/x5362e/x5362e03.htm
    kind: report
    license: FAO publication, cited not reproduced
documents:
  - title: Material Safety Data Sheet (MSDS), ComCORK Flooring, Sustainable Materials LLC (date prepared March 4, 2020)
    type: sds
    url: https://www.sustainablematerials.com/wp-content/uploads/2026/03/ComCORK-MSDS-SM-2026.pdf
    year: 2020
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 17
  unreachable: 0
  caveats: 2
  note: Written by an AI assistant on 2026-11-01. The Amorim table was checked against its raw HTML and the ASTM methods it names. NASA values come from pdftotext OCR of the scanned reports. Wikipedia figures were read through a summarising fetch and not checked against raw HTML. No MSA-I value is used as a cork value.
story:
  recipe:
    line: Cork is the bark of the cork oak (Quercus suber). By weight it is mainly suberin, lignin, polysaccharides and extractables. Amorim's P45 and P50 are sheets of cork particles, with particle sizes printed in its table.
    parts:
      - name: Suberin
        share_percent: 40
        role: The largest share in the Wikipedia composition figure (about 40% on average for cork in general).
      - name: Lignin
        share_percent: 22
        role: The second share in the same figure (22%).
      - name: Polysaccharides
        share_percent: 18
        role: Cellulose and hemicellulose together, 18% in the same figure.
      - name: Extractables
        share_percent: 15
        role: Extractable compounds, 15% in the same figure. Other constituents are not given a figure.
  risk_groups:
    - title: For people
      level: 0
      verdict: No hazard classification found in the sources we hold
      lead: We found no GHS classification for Amorim's P45 or P50. A cork flooring data sheet (ComCORK, a different product) says sanding, sawing or machining can make dust with a strong explosion hazard, and that wood dust can sensitize the skin and airways.
      points:
        - label: Processing
          line: Amorim says the sheets can be precision-trimmed and machined, and that they bond to most substrates with designated adhesive systems. The page gives no dust or hazard data.
        - label: Data status
          line: Amorim says its table gives typical values and is not a purchasing specification.
    - title: If the cork is heated
      lead: These points come from the booster design and the manufacturer page. No cork heating test data were found in the sources we hold.
      points:
        - label: Where it was used
          line: On the Shuttle booster, cork was used on the aft skirt because the predicted heating there was above what the sprayable ablator MSA-I could take (NASA 1985).
        - label: Ablation
          line: Amorim says the material forms a char layer that protects the inner material. No ablation rate or gas composition for cork was found.
    - title: Handling and refurbishment
      points:
        - label: Bonding
          line: Bonded cork was labour intensive to apply, and its adhesive layer was extremely difficult to remove during refurbishment studies (NASA 1985).
        - label: Assembly
          line: Amorim says the products bond to metal and composite with designated adhesive systems. The adhesive is not named.
  why: Cork thermal protection is an ablative and insulating material made from cork, the bark of the cork oak (Quercus suber). Its closed, air-filled cells give it low thermal conductivity, as the 1977 Dodge cork ablation report explains. NASA first considered bonded cork for the Space Shuttle Solid Rocket Booster, then used it on the aft skirt, where the predicted heating was above the range of the sprayable ablator MSA-I (NASA 1985). Amorim sells the P45 and P50 grades as aerospace grade thermal protection and says they were part of development programmes such as Aerofast, Ablamod, Retalt and SALTO. Viking and QARMAN flight claims are not supported by any source we read in this run.
  uses:
    - where: Space Shuttle Solid Rocket Booster aft skirt
      line: NASA's 1985 booster report says cork insulation was flown on the aft skirt because the predicted thermal environments were considerably above the performance range of MSA-I, whose thickness was limited to 1/4 in.
    - where: Re-entry probes
      line: Amorim says its TPS materials are qualified in several aerospace programmes as an ablative and thermal insulating heat shield for re-entry probes. The page does not name a specific probe.
    - where: Rocket engines, cryogenic tanks and payload fairings
      line: Amorim lists these as thermal protection application areas across a launch. The page does not tie each area to a grade.
  can_do:
    - label: Insulation
      value: '0.06'
      line: Amorim's typical thermal conductivity is 0.06 W/m•K for P45 and 0.07 W/m•K for P50, per its metric table.
    - label: Density
      value: '304'
      line: Amorim's typical density at 20 °C is 304 to 336 Kg/m3 for P45 and 448 to 512 Kg/m3 for P50.
    - label: Tensile strength
      value: '0.86'
      line: Amorim prints tensile strength as greater than 0.86 MPa for P45 and greater than 1.73 MPa for P50, per ASTM F152, Method B.
    - label: Flight use
      value: On the aft skirt
      line: NASA's 1985 report says cork insulation was being flown on the aft skirt of the Solid Rocket Booster at that time.
    - label: Original cork density
      value: '3'
      line: The 1977 report gives raw select cork at 3 to 3.5 lb/ft3 before formulation. The product grades are denser at 19 to 22 and 28 to 32 lb/ft3.
  compare: Against MSA-I, the sprayable epoxy-phenolic ablator NASA used on most of the booster, cork P45 is denser (19 to 22 lb/ft3 against 15 to 17 lb/ft3) and has the lower printed thermal conductivity (0.45 against 0.48 to 0.6 Btu-in/ft2-hr-F). The two sets of values come from different sources and test methods, and the test method for MSA-I is not stated in the report. Against raw select cork in the 1977 report, the P45 and P50 grades are denser, because they are processed from particles.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Specific heat
      benchmark: specific_heat
  handling:
    - Bonds to most metal and composite substrates with designated adhesive systems. The adhesive is not named in the sources we hold.
    - Machine or trim to the required geometry; Amorim says the parts can be precision-trimmed and machined.
    - Treat the values as typical, not a purchasing specification. Confirm with the manufacturer before use.
    - Control dust when sanding, sawing or machining. The ComCORK data sheet says such dust can present a strong explosion hazard if a dust cloud meets an ignition source.
  good_for:
    - Low thermal conductivity. Amorim prints 0.06 W/m•K for P45 and 0.07 W/m•K for P50.
    - Heritage on the Shuttle booster. NASA used it on the aft skirt where the sprayable ablator could not meet the predicted heating.
  watch_out:
    - Low tensile strength. Amorim prints greater than 0.86 MPa for P45 and greater than 1.73 MPa for P50.
    - Refurbishment is hard. Bonded cork was labour intensive to apply and extremely difficult to remove (NASA 1985).
    - The product is processed from cork particles, so its density of 304 to 512 Kg/m3 is far above raw select cork at 3 to 3.5 lb/ft3.
  verdict: Cork is a low-conductivity ablator with flight use on the Shuttle booster aft skirt. Our sources give no ablation rate, service temperature or Viking and QARMAN flight data for the cork products yet.