GOST 8420-74 PDF

Full title and description

GOST 8420-74 — "Paint and varnish materials. Methods for determination of relative (conditional) viscosity." The standard specifies laboratory procedures for determining the conditional (relative) viscosity of paint, varnish and related coating materials using flow/viscometric methods appropriate for Newtonian or near-Newtonian liquids.

Abstract

GOST 8420-74 provides standardized test procedures for measuring the conditional (relative) viscosity of coating materials and related products (including semi‑finished products and resins). It sets out sample preparation, measurement technique (viscometers/flow devices), temperature control and reporting requirements used for quality control and comparative testing. The 1974 standard has later been superseded by a 2022 revision (GOST 8420-2022) which modernises and consolidates methods.

General information

• Status: Superseded / replaced — originally active, later withdrawn in favor of GOST 8420-2022.
• Publication date: Approved May 17, 1974; commonly listed as published/registered 01 January 1975.
• Publisher: State Committee for Standards of the USSR (Gosstandart); successor activity and registration now handled by national bodies / Rosstandart for later editions.
• ICS / categories: 87.040 — Paints and varnishes (coatings industry).
• Edition / version: Original designation GOST 8420-74 (with amendments during the USSR period); replaced by GOST 8420-2022 (current revision published 2023).
• Number of pages: Typically listed as 7 pages for the 1974 edition.

Scope

Applies to paint and varnish materials and related products that are Newtonian or approximate Newtonian behaviour (including intermediates and resins). The standard defines procedures for determining conditional/relative viscosity for quality control, specification compliance and comparative evaluation of coatings. It is a laboratory test standard intended for use by testing and production laboratories in the coatings industry.

Key topics and requirements

• Definition of conditional (relative) viscosity for paint and varnish materials.
• Required test equipment and viscometers (specifications for apparatus and orifice/nozzle dimensions where applicable; related viscometer standard: GOST 9070-75).
• Sample preparation, homogenisation and conditions for dilution (if applicable).
• Temperature control and its effect on viscosity; specified test temperature and procedures for temperature stabilization.
• Measurement procedure (flow/time measurement or viscometric reading), calculation of conditional viscosity, rounding and reporting format.
• Precision, repeatability and reporting of test results (recommended number of repeats and expression of results).

Typical use and users

Used by coatings manufacturers, quality control and R&D laboratories, raw-material suppliers, inspection and certification bodies, and university/research laboratories that perform routine and comparative viscosity testing of paints, varnishes, resins and related products. Users typically consult this standard for method conformity, product specification testing and instrument selection.

Related standards

Standards commonly referenced alongside GOST 8420-74 (and its 2022 successor) include viscometer specifications (GOST 9070-75), standards for kinematic/dynamic viscosity measurement in liquids (GOST 33 series), laboratory glassware and thermometers (e.g., GOST 1770-74, GOST 28498-90), and international equivalents or related methods such as ISO/EN viscometric practices. For the 2022 revision, the issuing documentation lists these and other related GOSTs in its normative references.

Keywords

conditional viscosity, relative viscosity, paints and varnishes, coating materials, viscometer, flow time, sample preparation, test method, GOST 8420-74, GOST 8420-2022.

FAQ

Q: What is this standard?

A: GOST 8420-74 is a Soviet-era (1974) test standard titled "Paint and varnish materials. Methods for determination of relative (conditional) viscosity" that describes laboratory methods for measuring the conditional viscosity of coating materials.

Q: What does it cover?

A: It covers the procedures, apparatus requirements, sample preparation, temperature control, measurement steps and calculation/reporting rules needed to determine conditional (relative) viscosity for paints, varnishes, resins and similar products. The method is intended for Newtonian or near‑Newtonian liquids.

Q: Who typically uses it?

A: Coatings manufacturers, QC and R&D laboratories, instrument suppliers, inspection bodies and standardisation/technical laboratories use the method for production control, product specification testing and comparative research.

Q: Is it current or superseded?

A: The original GOST 8420-74 is superseded; the method was revised and replaced by GOST 8420-2022 (published/registered 2023), which is the current revision of the standard family. Users should refer to the 2022 edition for up-to-date procedures and references.

Q: Is it part of a series?

A: Yes — it belongs to the family of GOST standards for paints and varnishes (ICS 87.040) and is related to other test and equipment standards in that series (for example, GOST 9070-75 for viscometers and various GOSTs for viscosity and laboratory equipment). The 2022 edition collects and updates cross-references within the series.

Q: What are the key keywords?

A: Conditional (relative) viscosity, viscometer, paints and varnishes, coating materials, flow time, sample preparation, temperature control, GOST 8420-74, GOST 8420-2022.