Methods of test for clear finishes for wooden furniture, Part 4: Resistance to marking by liquids

IS 5807 Part 4 - Scope Summary & Key Specifications

Scope:
This part of IS 5807 specifies methods of test for clear finishes for wooden furniture focusing on resistance to marking by liquids.

Key Clauses & Specifications:

• Clause 5.2:
  Requires agreement between purchaser and seller on certain test conditions.

• Clause 8.1 - Acceptability Ratings:
  Minimum average ratings (from 5 observers) for acceptance are:

• Clause 3.4 - Viewing Cabinet:
  Construction details for viewing finish quality:

  • Material: 16 mm thick blockboard
  • Interior: Matt black paint
  • Lighting: 60 W frosted bulb over a 25 mm hole on a hinged platform
  • Purpose: Controlled observation of surface finish

• Clause 83.5 - Test Liquids Composition:

Summary:

IS 5807 Part 4 defines test methods and acceptance criteria for liquid resistance of clear wood finishes, including test liquid preparation, viewing conditions, and rating scales to ensure finish durability and quality.

flowchart TD
    A[Start: Prepare Test Liquid] --> B[Apply on Wood Finish]
    B --> C[Observe in Viewing Cabinet]
    C --> D[Rate Characteristics]
    D --> E{Ratings ≥ Acceptable?}
    E -->|Yes| F[Finish Accepted]
    E -->|No| G[Finish Rejected]

For detailed test procedures and apparatus, refer to full IS 5807 Part 4 document.

IS 5807 Part 4 — Test Principle Summary

• Test Setup:

  • Saturate a disc of filter material with the test liquid.
  • Place the disc on the test panel surface, cover with a watch-glass.
  • After the specified time, remove the disc.
  • Leave the panel undisturbed for 16–24 hours.
  • Rub test area gently with dilute acetic acid on a soft cloth, polish dry, then visually examine for marks.

• Disc Placement (Clause 6.1):

  • Use at least two discs per test liquid.
  • Each disc center ≥ 40 mm from panel edges.
  • Minimum distance between disc centers = 50 mm.

• Viewing Cabinet (Clause 3.4):

  • Constructed from 16 mm thick blockboard, interior matt black.
  • 60 W frosted bulb positioned over a 25 mm hole for illumination.
  • Provides consistent lighting for visual inspection.

• Test Liquids (Clause 4.1):

  • As agreed between purchaser and supplier.
  • For potable spirits, tea, coffee, use compositions per Appendix A.

Visual: Viewing Cabinet Setup

graph LR
A[16 mm Blockboard Cabinet] --> B[Matt Black Interior]
B --> C[25 mm Hole on Sloping Side]
C --> D[60 W Frosted Bulb on Hinged Platform]
D --> E[Illuminates Area Under Observation]

This procedure ensures standardized evaluation of surface marking resistance as per IS 5807 Part 4.

IS 5807 Part 4: Reagents and Apparatus - Key Specifications

Composition of Test Liquids (Clause 83.5 & Appendix A)

Test Procedure (Clause 2.1)

• Saturate a material disc with test liquid.
• Place on test panel, cover with watch-glass.
• After specified time, remove disc.
• Leave panel undisturbed for 16-24 hours.
• Rub test area with soft cloth damped in dilute acetic acid.
• Polish with dry cloth and visually inspect for marks.

Notes:

• Ordinary denatured spirits must conform to IS: 324-1959.
• Test liquids must be agreed upon by purchaser and supplier if different from above.
• Apparatus includes watch-glass, soft cloth, and vessels for infusion.

flowchart TD
    A[Prepare Test Liquid] --> B[Saturate Material Disc]
    B --> C[Place Disc on Test Panel]
    C --> D[Cover with Watch-Glass]
    D --> E[Wait Specified Time]
    E --> F[Remove Disc]
    F --> G[Rest Panel 16-24 hrs]
    G --> H[Rub with Dilute Acetic Acid Cloth]
    H --> I[Polish with Dry Cloth]
    I --> J[Visual Inspection for Marks]

This ensures standardized testing of clear finishes for wooden furniture against liquid marking.

IS 5807 Part 4 (1975) - Test Liquids Specifications

Key Test Liquid Compositions (Clause 4.1 & Appendix A)

Notes:

• Denatured spirits conform to IS: 324-1959.
• Tea and coffee infusions are prepared fresh and cooled before testing.
• Test liquids are agreed upon between purchaser and supplier if other than above.

Viewing Cabinet (Clause 3.4)

• Constructed from 16 mm thick blockboard, interior matt black.
• Equipped with 60 W frosted bulb positioned over a 25 mm diameter hole.
• Used for observing test results under controlled lighting.

This ensures consistency in testing the resistance of clear finishes on wooden furniture to marking by liquids.

IS 5807 Part 4: Preparation of Test Surface - Key Points

• Test Surface Area (Clause 5.1.1):
  Prepare a sufficiently large area to allow for repeat or additional tests.

• Aging of Final Coat (Clause 5.3):

  • Temperature: 27 ± 2°C
  • Relative Humidity: 65 ± 5%
  • Duration: Minimum 28 days (can be reduced by agreement)

• Test Liquid Application (Clause 2.1):

  • Saturate a disc of material with the test liquid.
  • Place on test panel surface, cover with a watch-glass.
  • After specified time, remove disc, leave panel undisturbed for 16-24 hours.
  • Rub test area gently with a soft cloth dampened in dilute acetic acid, polish with dry cloth, then visually inspect for markings.

Summary Table: Test Surface Preparation

flowchart TD
    A[Prepare Test Surface] --> B[Apply Saturated Disc]
    B --> C[Cover with Watch-glass]
    C --> D[Wait Specified Time]
    D --> E[Remove Disc]
    E --> F[Rest 16-24 hours]
    F --> G[Rub with dilute acetic acid]
    G --> H[Polish with dry cloth]
    H --> I[Visual Inspection]

This process ensures consistent and reliable testing of surface resistance to liquids per IS 5807 Part 4.

IS 5807 Part 4: Test Procedure Summary

1. Aging of Final Coat (Clause 5.3):

• Age at 27 ± 2°C and 65 ± 5% RH with free air access
• Minimum aging period: 28 days (can be reduced by agreement)

2. Test Liquids (Clause 4.1 & Appendix A):

• Liquids agreed between purchaser & supplier
• Standard compositions (Clause 83.5):

3. Viewing Cabinet (Clause 3.4):

• Constructed from 16 mm thick blockboard, interior matt black
• 25 mm diameter hole on sloping side, 60 W frosted bulb positioned directly over hole
• Used for visual assessment of finishes

flowchart LR
  A[Final Coat Application] --> B[Aging: 27±2°C, 65±5% RH, ≥28 days]
  B --> C[Test Liquid Preparation]
  C --> D[Apply Test Liquid on Sample]
  D --> E[Visual Inspection in Viewing Cabinet]

This ensures standardized evaluation of resistance to marking by liquids on wooden furniture finishes.

IS 5807 Part 4: Assessment and Reporting of Results

1. Rating Code for Test Area (Clause 7.2)

2. Assessment Procedure (Clause 6.8.1 & 7.3)

• Position test panel 550 mm from cabinet back, equidistant from sides.
• Move eye to track lamp reflection around test area to detect markings.
• At least 5 independent assessors rate each test area.
• No intermediate ratings (e.g., 2.5) allowed.

3. Acceptability Criteria (Clause 8.1)

This ensures objective, repeatable reporting of surface condition changes post-testing.

IS 5807 Part 4 — Acceptability Criteria

Key Specifications (Clause 8.1)

Minimum average ratings from 5 independent observers must meet:

Rating Scale (Clause 7.2)

Assessment Notes (Clause 7.3)

• At least 5 persons independently rate each test area.
• No intermediate ratings (e.g., 2.5) allowed.
• Average of all 5 ratings determines acceptability.

This ensures consistent, objective evaluation of surface conditions per IS 5807 Part 4.

IS 5807 Part 4 — Composition of Test Liquids (Clause 4.1 & Appendix A)

Notes:

• Denatured spirits must conform to IS: 324-1959.
• Infusion times and ratios ensure consistent test liquid preparation.
• Variability in groups like detergents or fruit juices means results may not represent all members.

Quick Formula Summary:

• Potable Spirits:
  [ \text{Volume ratio} = 1:1 \quad (66\ OP\ spirits : \text{water}) ]

• Toilet Spirits:
  [ \text{Volume ratio} = 8:1 \quad (66\ OP\ spirits : \text{water}) ]

flowchart TD
    A[66 OP Denatured Spirits] -->|Mix 1 volume| B[Potable Spirits Test Liquid]
    C[Distilled Water] -->|Mix 1 volume| B
    
    D[66 OP Denatured Spirits] -->|Mix 8 volumes| E[Toilet Spirits Test Liquid]
    F[Distilled Water] -->|Mix 1 volume| E
    
    G[Indian Tea (1g)] -->|Infuse with 100 ml boiling water| H[Tea Test Liquid]
    I[Ground Coffee (1g)] -->|Infuse with 12 ml boiling water| J[Coffee Test Liquid]

This ensures standardized test liquids for evaluating wood finishes as per IS 5807 Part 4.