ASTM D6677-18 (2022) PDF

Full title and description

St ASTM D6677-18 (2022) — Standard Test Method for Evaluating Adhesion by Knife. A short, qualitative field and laboratory procedure for assessing the adhesion of coating films to substrates or between coating layers by probing/cutting with a sharp knife and rating the ease and extent of coating removal.

Abstract

This standard defines a simple, subjective test technique used to evaluate the adhesion of paints and protective coatings by scoring or cutting with a utility knife and observing the degree to which the coating is removed or detached. The method provides a performance evaluation scale based on the difficulty of removal and size of detached chips. It is intended as a quick check for generally adequate adhesion rather than a quantitative pull-off measurement.

General information

• Status: Active — reapproved (2022).
• Publication date: Original edition 2018; current edition reapproved December 22, 2022 (designated D6677-18(2022)).
• Publisher: ASTM International (Committee D01 — Paint and Related Coatings, Materials, and Applications; Subcommittee D01.46).
• ICS / categories: 19.040; 25.220.01 (surface treatment and coatings / environmental testing & coatings).
• Edition / version: D6677-18(2022) — 2018 edition, reapproved 2022 (sometimes shown as D6677-18R22).
• Number of pages: 2 pages (concise test method).

Scope

This test method covers the procedure for assessing adhesion of coating films to substrates or between coats using a knife to cut and pry the coating. It is intended for use in both laboratory and field conditions and for a wide range of substrates (for example, metal, concrete, or previously coated surfaces). The method is qualitative and subjective, intended to establish whether adhesion is generally adequate. It is not intended for overly thick coatings that cannot be cut to the substrate in a single knife stroke, nor does it provide a quantitative correlation to pull-off or tape tests.

Key topics and requirements

• Test principle: cutting/probing the coating with a sharp utility knife and attempting to remove coating chips to assess adhesion.
• Required apparatus: sharp utility knife or equivalent cutting tool; clean test area and, where applicable, magnification for evaluation.
• Performance evaluation scale: a rating system based on difficulty of removal and size/amount of detached coating.
• Applicable materials: coatings on common substrates (steel, concrete, other coatings) when thickness allows cutting to substrate in one stroke.
• Limitations: qualitative/subjective method; not suitable for overly thick coatings; does not directly correlate to quantitative adhesion measurements (e.g., pull-off tests).
• Cross-references: recommends use or comparison with other adhesion methods (see related standards) when quantitative data are required.

Typical use and users

Used by coatings manufacturers, quality control laboratories, specifiers, field inspectors, contractors, and maintenance personnel as a rapid, low-cost check of coating adhesion during application, inspection, or failure investigation. Typical uses include spot checks on production lots, pre- and post-application inspections, and troubleshooting of coating failures where a quick assessment of intercoat or substrate adhesion is helpful.

Related standards

Commonly referenced or complementary standards include ASTM D2197 (scrape adhesion), ASTM D3359 (tape adhesion), ASTM D4541 (pull-off adhesion test), ASTM D7234 (pull-off strength on concrete), and international methods such as ISO 2409 (cross-cut adhesion test). Earlier or related ASTM editions (for historical reference) include D6677-07 and prior reapprovals.

Keywords

adhesion; knife adhesion; coating adhesion; intercoat adhesion; paint; coating evaluation; field test; qualitative adhesion; substrate; utility knife test; adhesion rating.

FAQ

Q: What is this standard?

A: ASTM D6677-18(2022) is a short, qualitative test method that describes how to evaluate the adhesion of a coating by cutting/probing with a knife and rating the amount and difficulty of coating removal.

Q: What does it cover?

A: It covers procedure, required tool (sharp utility knife), evaluation criteria (performance scale), application limits (not for overly thick coatings), and guidance for use in laboratory or field settings. It is intended to determine whether adhesion is generally adequate, not to provide a quantitative adhesion value.

Q: Who typically uses it?

A: Coatings manufacturers, QA/QC laboratories, inspectors, contractors, maintenance engineers, and spec writers who need a quick, low-cost adhesion check during production, application, or failure analysis.

Q: Is it current or superseded?

A: The 2018 edition (D6677-18) was reapproved in 2022 and is published as D6677-18(2022). It is current as a reapproved standard; users should check with the publisher for any later revisions or withdrawals.

Q: Is it part of a series?

A: It is part of the family of ASTM test methods for coating adhesion and related performance tests maintained by Committee D01 (Subcommittee D01.46). It is commonly used alongside other ASTM adhesion tests such as D2197, D3359, and D4541.

Q: What are the key keywords?

A: Adhesion, knife adhesion, coating adhesion, intercoat adhesion, paint, field test, qualitative evaluation, substrate, utility knife.