static/dynamic test method to evaluate idle day’s tolerance of hull … klijnstra.pdf · 2018. 7....

Presentation 19th ICMCF 26-6-2018

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Presentation at 19th ICMCF, June 26, 2018, Melbourne, Florida, USA

Static/dynamic test method to evaluate idle day’s tolerance

of hull coatings

Job Klijnstra, Mark Bakker

Endures BV, Den Helder, The Netherlands

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Content

Introduction

Test setup and protocol

Fouling development

Fouling release

Conclusions


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Independent contract research laboratory

Corrosion, Failure analysis and Antifouling research since 1964

Expertise:

Corrosion

Electrochemistry

Metallurgy

Antifouling

Microbiology

Coating inspections and performance testing

Material durability in seawater (composites, adhesive joints)

Natural seawater

Outdoor exposure

In-house laboratory of Royal Netherlands Navy

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ENDURANCE through RESEARCH

a initiative Rotor equipment in natural seawater for dynamic ageing

Raft exposure facility in harbour for efficacy tests and static ageing

Raft and rotor equipment can be used to answer following questions:

How much fouling will accumulate on hull paints after different periods of

static immersion

At what rotation speed can such fouling be removed again

Coatings applied onto PVC rotor panels

After dynamic ageing panels mounted on support rack for raft exposure

Panels retrieved after several weeks static exposure

Idle day’s tolerance test


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Test protocol idle day’s tolerance test5

Dynamic ageing

(17 kn, 25ᵒ C)

- 1 month

- 4 months

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- 5 months

Static raft exposure(30, 120 cm depth)

- 5 weeks

- 10 weeks

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- 7 weeks

- 14 weeks

Rotation testing

- 8 knots

- 15 knots

T = 5, 15, 60 & 180 min

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- 15 knots

T = 5, 15, 60 & 180 min

9 paint systems 136 panels in total

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Dynamic ageing

Rotor ageing at 17 knots

1 month & 4 monthsPanels mounted on PVC supports

prior to immersion at the raft

Rotor drum in natural seawater

Drum diameter: 50 cm

Rotation speed: 5 – 30 knots

Turbulent flow

Volume: 600 L

Max. refresh rate: 300 L/hr

Water temperature: 15 – 35 °C

Curved panels (15x8 cm), N = 70


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Fouling development

One set of panels retrieved after 5 weeks static exposure

Mainly algae/diatom fouling on panels; very few barnacles on some panels.

Blank panels strongly covered with barnacles and green algae.

Fouling development

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Second set of panels retrieved after 10 weeks static exposure

Mainly algae/diatom fouling on the panels and occasionally some barnacles and a few tubeworms.

Blank panels and rack and support strongly covered with barnacles and sea squirts.


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Fouling development

Fouling after 5 (left) and 10 weeks (right) static exposure at 30 cm depth;

Mainly green algae and diatoms; few barnacles (only on paints 5 and 6).

Overall more fouling on panels after 10 weeks.

Paints 1 and 9 have clearly less fouling than other paint systems.

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Fouling development

Same picture of panels exposed at 120 cm depth for 5 weeks (left) and 10

weeks (right) static exposure.

Less fouling at this depth, hardly any green algae, mainly diatom slime.

10 week panels slightly more fouling.

Paint 1 had no fouling after 10 weeks static.


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1 M vs 4 M dynamic ageing (5 & 10 weeks static, 120 cm depth)

10 weeks

5 weeks

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More fouling found on paints 2 – 8 in comparison to paints 1 and 9, both

after 5 and 10 weeks static exposure

After 10 weeks more dense fouling found on paints 2 – 8 in comparison

to panels aged for 5 weeks

Panels exposed at 30 cm depth contained more algae and diatom /slime

fouling in comparison to panels at 120 cm depth

Paints 1 (FRC) and 9 (SPC) have very little fouling even after 10 weeks

raft exposure

Barnacles were only found on two out of the nine paint systems

investigated

No difference in fouling development was found between panels with

different dynamic ageing periods, except for paint 7.

Conclusions fouling development


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Fouling release

Paint 1

Figure 21. Paint #1 (1-1-4-8-A), 1 month dynamic ageing, 5 weeks raft exposure at 30 cm.

Left: at start of release test; Right: after 5 min rotation at 8 knots.

Figure 22. Paint #1 (1-6-8-8-A). 4 months dynamic ageing, 10 weeks raft exposure at 30 cm.

Left: at start of release test; Middle: 5 min rotation at 8 knots; Right: 3 hrs rotation at 8 knots.

Figure 48. Paint #9 (9-1-4-8-A). 1 month dynamic ageing, 5 weeks raft exposure at 30 cm depth.


Paint 9

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Fouling release

Figure 30. Paint #3 (3-6-8-15-A). 4 months dynamic ageing, 10 weeks raft exposure at 30 cm depth. Left:

start of release test; Middle: 5 min rotation at 15 knots; Right: 3 hrs rotation at 15 knots.

Paint 3


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Fouling release

Paint 6

Figure 37. Paint #5 ((5-1-8-15-A). 1 months dynamic ageing, 10 weeks raft exposure at 30 cm

depth. Left: start of release test; Middle: 5 min at 15 knots; Right: 3 hrs rotation at 15 knots.

Paint 5

Figure 35. Paint #5 (5-6-4-8-A). 4 months dynamic ageing, 5 weeks raft exposure at 30 cm depth.


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Paint#7 – 5 weeks static immersion, 8 knots

At the start After 180 min

1 month

4 months

4 months

1 month

Immersion

depth 30 cm

Immersion

depth 120 cm

After 5 min


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Regardless of rotation speed, immersion depth, static exposure period and

dynamic ageing period:

most fouling is released during first 5 min of rotation; subsequent rotation

times (up to 180 minutes) gave in most cases only little further release.

Speed of 8 knots gives very little fouling release, especially on A panels (30

cm depth) for most products.

Speed of 15 knots gives better release on both A and B panels although also

then some products do not get clean.

Paints 1 and 9 are very well cleaned already at 8 knots.

Paints that had barnacle fouling did not get clean after 3 hrs rotation at 8 and

15 knots.

Prolonged rotation for 1 week at 15 knots did not give any further release of

fouling.

Conclusions release tests

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B panel

1

3

5

7

A panel

2

4

6

8

B panelA panel

(4 months D, 10 weeks S, 5 months D) 7 weeks Static

Fouling development in 2nd static ageing period


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Fouling release after 2nd static ageing period

Paint 3

At the start After 5 min After 60 min After 180 min

Paint 7

Paint 8

Panels (4 months D, 10 weeks S, 5 months D) 7 weeks static at 30 cm depth

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Paint 3

Paint 8

Paint 1



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Paint 1

Paint 4

Paint 5

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Conclusions

The test results illustrate that for current antifouling systems

Static exposure periods between 5 and 14 weeks do not necessarily

lead to severe fouling;

On some products hardly any fouling can even be observed;

For other products differences can be found in the speed required

for removal of existing fouling.

The test methodology can be used to discriminate antifouling coatings on

their performance after various idle times or cyclic ageing regimes.

Additionally, the test may give further insight in minimal speeds required

to remove different fouling patterns.



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Thank you very much for your attention

[email protected] +31 6 10490059

static/dynamic test method to evaluate idle day’s tolerance of hull … klijnstra.pdf · 2018. 7....

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