Two Pack Epoxy Zinc Phosphate Weldable Primer Specification

KS 1992:2005

KENYA STANDARD

Two pack epoxy zinc phosphate weldable primer—Specification

Public Review Draft December 2005

KENYA BUREAU OF STANDARDS (KEBS) KENYA STANDARD KS 1992:2005

TECHNICAL COMMITTEE REPRESENTATION

The following organizations were represented on the Technical Committee:

Jotun paints ltd. Sadolin Paints (E.A.) Ltd. Unique supplies. Kenya Ferry Services Crown-Berger Ltd. Government Chemist’s Department Kenya Ports Authority SAJCO paints company Southern engineering company ltd (SECO) Galaxy paints ltd Kenya Bureau of Standards — Secretariat

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KENYA BUREAU OF STANDARDS (KEBS)

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Coast Regional Office Western Kenya Regional Office Rift Valley Regional Office P.O BOX 99376 Mombasa P.O BOX 2949 Kisumu P.O Box 8111 Eldoret Tel: (+254 041) 475119 Tel: (+254 057) 22396/23549 Tel: (+254 053) 33151/63377 E-mail: [email protected] E-mail: [email protected] Fax: (+254 053) 33150 Fax: (+254 041) 472666 Fax: (+254 057) 21814

Foreword

This Kenya Standard has been prepared by the Technical Committee on Paints and Allied Products under the supervision of the Chemical Industry Standards Committee, and it is in accordance with the procedures of the Bureau.

Epoxy based paint is required for the painting of steel structures and equipments for shore based equipment. This type of primer is used as a base coat in epoxy painting system and will have no deleterious effect on welding..

This standard specifies such important parameters like volatile matter, drying times, pot life and skinning among others. The standard covers all range of colours

During the preparation of this standard, reference was made to; IS 14209— epoxy zinc phosphate weldable primer, two component specification

Acknowledgment is hereby made for the assistance derived from this source

Two pack epoxy zinc phosphate weldable primer—Specification

1 Scope

This Kenya Standard prescribes the requirements and test methods for two pack epoxy zinc phosphate weldable primer. This material is used as a base coat for the painting of steel structures /equipment where corrosion protection and chemical resistance under marine atmospheric conditions are required. .

2 Normative references

The following publications are indispensable in the application of this standard:

KS 161-4, Paints and varnishes — Determination of specific gravity or weigh/litre

KS ISO 4618-1, Paints and varnishes — Terminology

KS 161-5, Methods of test for paint, varnishes, lacquers and enamels-Determination of volatile and non volatile matter

KS 163, Colours of ready mixed paints

KS 161-2, Methods of test for paint, varnishes, lacquers and enamels-Standard panels for testing

3 Definitions

For the purposes of this standard, the definitions given in KS ISO 4618-1 apply together with the following glossary of terms related to paint.

3.1 Pot life Maximum time during which a coating material supplied as separate components should be used after they have been mixed together.

4 Requirements

4.1 Composition

4.1.Two pack epoxy zinc phosphate weldable primer shall be epoxy based. The manufacturer shall specify the principal type of binder and the curing agent used in the paint. The principal anticorrosive pigment shall be zinc phosphate

4.1.The paint shall consist essentially of two components, base and hardener or catalyst solution to be mixed as recommended by the manufacturer so as to satisfy all the requirements of this standard.

4.2 Odour The odour of the Two-pack epoxy zinc phosphate weldable primer in the container, during and after application shall not be abnormally pungent, offensive or disagreeable.

When visually examined, Two pack epoxy zinc phosphate weldable primer shall be free from skins and lumps. The container shall be free from rust and moulds.

4.4 Other requirements

4.4.1 Wet paint

The wet mixed material shall also comply with the requirements given in the Table 1 below:

Table 1 — Requirements for the wet coat, Two pack epoxy zinc phosphate weldable primer

Item no Characteristic Requirements Test method

1) Drying time a) Surface dry 4 hours, maximum KS 909 Annex F b) Hard dry 24 hours, maximum 2) Viscosity1at 25oC Pa.s 68 - 72 KU Use the rotation paddle viscometer 3) Solids content, % m/m 35, minimum KS 161 Part 5 4) Pot life, hours. 4, maximum. Annex A 5) Flash point 30 0c, minimum. KS 161 part 17

6) Specific gravity at 25 oC 1.25-1.55 KS 161 Part 4, 7) Wet opacity 30m KS 1275 Annex B 8) Zinc phosphate content, min 15% Annex B

4.4.2 Dry coat2

1 Viscosity units.

To change viscosity units from KU (Krebs unit) to mPa.s or cP the following formula shall apply:

Viscosity range of 200-2100 mPa.s (cP) ln (KU)=1.1187+0.8542*ln (0.1938v +36)-0.0443(ln (0.1938v +36) )2

Viscosity range of 2100-5000 mPa.s (cP) ln (KU)=1.18118+0.596*ln (0.1938v +36)-0.0206(ln (0.1938v +36) )2

Where KU is the viscosity in Krebs units at 250 and v is the viscosity in mPa.s (cP) at 250

2 Tests mentioned 4.42 shall be carried out for the full system that is 1 coat of primer, 1 coat of intermediate and 1 coat of finishing paint or 1 coat of primer and 1 coat of finishing paint supplied by the same firm after 168 hours curing at 30°C.

Table 2— Requirements for the dry coat, Two pack epoxy zinc phosphate weldable primer.

Item no Characteristic Requirements Test method

1) Colour Close match with the colour KS 163 in the Kebs universal colour chart. 2) Dry film thickness per coat 15-25µm, Mikro test method

3) Finish Matt Visual examination

4) Scratch hardness using No such scratches shall KS 161 part 19 15N. produce a bare metal 5) Flexibility and adhesion There shall be no visible KS 161 part 16 using 12mm mandrel. damage or detachment of film after 48 hours.

6) Salt spray test The film shall not show KS 161 part 15 signs of blistering, staining ,loss of adhesion or creep of corrosion from scratch

4.19 Sampling

A minimum representative sample of 2L of paint shall be taken randomly from the factory, market or elsewhere and tested for compliance with the requirements of the standard.

5 Packaging and marking

5.1 Packaging

The paint shall be packed in suitable containers in the following measurers: 20 L, 4 L, 2.5 L, 1 L, ½ L and ¼ L.

5.2 Marking

5.2.1 Marking on the container

Each container shall be marked legibly and indelibly with the following: a) the words Two pack epoxy zinc phosphate weldable prime a) name and address of the manufacturer and/or registered trader mark; b) volume of the material in L;

c) instructions for use; d) spreading capacity in M2/L e) Shelf life.

© KEBS 2005 — All rights reserved 7 KENYA STANDARD KS 1992:2005 5.2 Marking on the label of the container a) Date of manufacture b) Instructions for correct use, disposal and safety requirements. c) Pot-life d) Shelf life f) colour; g) Batch number

Annex A (normative)

Determination of pot life A.0 General The time taken to double the viscosity from the original value shall be considered the pot life of the material.

A.1 Apparatus

A.1.1 Test panels

A.2 Reagents

A.2.1 Component parts i.e. base and hardener or catalyst.

A.3 Procedure

A.3.1 Thoroughly mix component parts in the ratio specified by the paint manufacturer to give a sample of 200 ml by volume.

A.3.2 Within 10 minutes of mixing determine the viscosity using a rotating paddle viscometer.

A.3.3 Allow the mixed sample of paint to stand in a suitable airtight container and determine viscosity at the end of the specified time.

. A.4 Report

A.4.1 Report whether viscosity has doubled at 25 0c within 4 hours. .

B-O GENERAL Metallic zinc is estimated, by determining the total reducing power by dissolving it in acidulated ferric chloride solution and titrating with standard potassium permanganate solution.

B-l REAGENTS

B - 1.1 Standard Potassium Permanganate Solution (0.1 N)

0 Heat 5 g of potassium permanganate (KmnO4) for one hour at 100 +2 C. Dissolve 3.16 g of Potassium permanganate in water and dilute it to one litre. Allow it to stand for 7 days. Filter through a medium porosity fritted disc and standardize against sodium oxalate as follows:

Dissolve 0.25 to 0.30 g of sodium oxalate in 250 ml of hot water (80-9O0C) and add 15 ml sulphuric acid (1:1). Titrate at once with KMn04 solution stirring the liquid rigorously and continuously. The KMn04 shall not be added more rapidly than 10 to 15 ml/min and the last 0.5 to 1 ml shall be added drop wise with particular care to allow each drop to be fully decolourised before the next is introduced. The solution shall not be below 60°C by the time the end point has been reached. Keep the KMn04 solution in a brown glass-stoppered glass bottle and store in a dark place.

B-l.2 Ferric Chloride Solution

Prepare a solution containing 20 g of ferric chloride (FeCl3.6H20) and 20 ml of 20 percent sodium acetate solution. It is advisable to make up one day’s requirement at a time.

Note: 40 ml are required for each determination.

B-l.3 Sodium Acetate Solution Dissolve 200 g of anhydrous sodium acetate (NaC2H302) or 332 g of NaC2H302.3H20 in water and dilute to 1 litre.

B-l.4 Zimmerman - Reinhardt Solution

Prepare one litre of solution containing 67 g of manganese sulphate (MnS04.4H2O), 130 ml of sulphuric acid (H2SO4) (sp. gr. 1.84) and 138 ml of phosphoric acid (85 percent).

B-2 PROCEDURE

B-2.1 Weigh 0.2 g of the sample of the pigment. Transfer immediately to a dry 600 ml heavy-wall Erlenmeyer flask and add 50 ml of the FeCl3 solution. Tightly stopper the flask and agitate constantly for approximately 15 minutes. As soon as all zinc dust is dissolved, add 50 ml of the Zimmerman – Reinhardt solution and 250 ml of water. Titrate with 0.1 N KMn04 solution.

B-2.2 Make a blank determination, following the same procedure and using the same amounts of‘ all reagents except the pigment.

B-3 CALCULATIONS Calculate the percent of metallic zinc as follows: Metallic zinc, percent = {(V-B) x N x 0.032 7/ W}

Where:

V = ml of KMn04 solution required titration,

B = ml of KMnO4 solution required for titration of blank

N = normality of the KMn04 solution, and W = grams of sample used.

NOTE - Metallic zinc content determination method ns per ASTM D 521-28 may be used as an alternate method.