VOM Accelerated - Blygold Hawaii

The following accelerated testing results were published by Adviescentrum VOM, an independent labratory located in Bilthoven, Netherlands. The results of the accelerated testing from the these tests: Tropical, Salt Spray, Acid Salt Spray, Kesternich, and Exchange demonstrate that Blygold PoluAl is a highly effective protective coating treatment for aluminum-fin, copper-tube coils installed in a variety of corrosive environments.

1. INTRODUCTION

On 15 December 1998 Advice Centre VOM received a fax message with the order from the company Blygold of Houten to execute corrosion tests on coated heat exchangers. Advice Centre VOM is an independent centre for advice and information on surface technology of materials. Advice Centre VOM is ISO 9002 certified and has a paint-technical laboratory at its disposal, which is certified according to NEN-EN 45001 (Lab) and NEN-EN 45004 (inspection).

The scope of work can be divided into three sections:

INSPECTION/SUPERVISION

Our group of inspectors are fully qualified to act on your behalves for full and part time inspection on surface treatments on all substrates. This involves new work as also maintenance. We occupy personal on all fields of industry and buildings. As an example we mention the following projects: refineries, bridges, ships, pontoons, offshore equipment, electricity pilons, chemical industry, steel structures, yachts etc., buildings, houses, offices, stations, etc., aluminium profiles and panels, coil coating, powder coatings, automotive industry and industrial application of coatings etc. Inspections are mainly in The Netherlands and surrounding countries. Inspection of industrial coatings for the aluminium and automotive industry are executed all around Europe.

CONSULTANCY/EXPERTISE

Surface treatment

Formulation of

- façades
- installations
- steel structures
- consumer goods

- specifications
- procedures

We are specialised in the analysis of failures in surface treatments. On behalf of our customers we travel around the whole world. Problems concerning protective coatings and linings in ships, petro-chemical industries and concrete are solved by our consultants.

In the field of maintenance we are involved in the realization and organization of systematic maintenance projects. After inspection and evaluation of the quality and amount of surfaces we advice your organization on the most economic way of maintenance. We therefore use our knowledge of modern surface technologies, the newest specifications and normalisations (we are most of the time member of the specifying comitty) and the newest management methods in the motivation and specification methods.

TESTS ARE CARRIED OUT

Adviescentrum VOM carries out all kind of tests for the benefit of the surface technology industry all over the world. The tests are carried out in accordance with:

VMRG requirements Dutch requirements for building industry
Qualicoat requirements European requirements for coating industry
Keur Enamel Dutch requirements for enamel industry
Euras-EWAA requirements European requirements for anodizing industry
Qualicor requirements European requirements for automotive industry

For these purposes the Consultancy Centre has a modern, fully equipped laboratory.

2. TEST DESCRIPTIONS

2.1. Tropical test (part of cycle exchange test)

The tropical test is executed at a temperature of 40°C and 100% relative humidity, the test samples are placed in this conditioned room for a certain period of time. After testing the test samples are assessed as to blistering, detachment and any other defects.

2.2. Salt spray test (neutral) (also part of cycle exchange test)

The resistance against salt water spray is determined by means of a neutral salt spray test according to SS DIN 50021. In this test the test samples are exposed to a spray of a 5% salt solution at a temperature of 35°C. The test samples are checked for blistering, detachment and any other defects. The neutral salt spray test is mostly for coatings on steel and galvanized steel. Normal duration : 500 hours.

2.3. Salt spray test (acid)

The resistance against salt water spray is determined by means of an acid salt spray test according to ESS DIN 50021. In this test the test samples are exposed to a spray of a 5% salt solution with a pH value of 3, at a temperature of 35°C. The acid salt spray test is mostly for coatings on aluminium. Normal duration : 1000 hours. The pH is set with acetic acid. The test samples are checked for blistering, detachment and any other defects.

2.4. Kesternich test

The Kesternich test is executed according to DIN 50018-SFW 2,0 S. This gives an accelerated picture of the behaviour of the tested system in an industrial atmosphere.

Here the test samples are exposed to an atmosphere of 100% r.h. and SO2-gas (2 litres) at an increased temperature (40°C) for 8 hours. Normal duration 1000 hours with 0,2 litres SO2-gas.

2.5. Exchange test according to VDA 621-415

The cycle consist of:

1 day salt spray test (DIN 50021)
4 days tropical test (DIN 50017)
2 days exposure at 18°C to 28°C (DIN 50014).

Because of insufficient corrolation between the results of the salt spray tests and the results in the field, exchange tests are more and more applied.

3. RESULTS CORROSION TESTS

3.1. Weight determination before and after testing.

Sample no:	Test	(A) Weight before test with labels	(B) Weight after test only drying	(C) Weight after rinsing and drying	Difference A/B	Difference A/C	Difference B/C
J905/1	exchange test 3000 hours	210 gr.	221 gr.	219 gr.	+11 gr.	+9 gr.	-2 gr.
J905/2	exchange test 3000 hours	193.5 gr.	203 gr.	201 gr.	+9.5 gr.	+7.5 gr.	-2 gr.
J905/3	neutral salt spray 3000 hours	220 gr.	230 gr.	228 gr.	+10 gr.	+8 gr.	-2 gr.
J905/4	neutral salt spray 3000 hours	200.5 gr.	209 gr.	207 gr.	+8.5 gr.	+6.5 gr.	-2 gr.
J905/5	acid salt spray 3000 hours	194 gr.	200 gr.	196 gr.	+6 gr.	+2 gr.	-4 gr.
J905/6	acid salt spray 3000 hours	190 gr.	199 gr.	192 gr.	+9 gr.	+2 gr.	-7 gr.
J905/7	Kesternich after 80 cycles	194.5 gr.	218 gr.	216 gr.	+24 gr.	+21.5 gr.	-2 gr.
J905/8	Kesternich after 80 cycles	204 gr.	227 gr.	225 gr.	+23 gr.	+21 gr.	-2 gr.

3.2 Coated heat exchangers before testing

Sample no: J905/0	Result: The inside shows the condition of the Blygold PoluAl coating . A remarkable detail is that the important fin perforations are not blocked.

3.3. Exchange test (3000 hours)

Sample no. J905/1 and 2	Result: The inside shows no defects, the coating is still in a perfect condition.

3.4. Neutral salt spray test (3000 hours)

Sample no. J905/3 and 4	Result: The inside shows no defects, the coating is still in a perfect condition.

3.5. Acid salt spray (3000 hours)

Sample no. J905/5 and 6	Result: The inside shows no defects, the coating is still in a perfect condition.

3.6. Kesternich test (80 cycles)

Sample no. J905/7 and 8	Result: The inside shows hardly any defects except for a light discoloration.This dicoloration is the effect of sulfur pollution on the surface. The coating is still in a perfect condition.