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Presentation 19th ICMCF 26-6-2018
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
Presentation 19th ICMCF 26-6-2018
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
Presentation 19th ICMCF 26-6-2018
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Test protocol idle day’s tolerance test5
Dynamic ageing
(17 kn, 25ᵒ C)
- 1 month
- 4 months
------------------------
------------------------
- 5 months
Static raft exposure(30, 120 cm depth)
- 5 weeks
- 10 weeks
----------------------------
----------------------------
- 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
Presentation 19th ICMCF 26-6-2018
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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.
Presentation 19th ICMCF 26-6-2018
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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.
Presentation 19th ICMCF 26-6-2018
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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
Presentation 19th ICMCF 26-6-2018
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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.
Left: at start of release test; Middle: 5 min rotation at 8 knots; Right: 3 hrs rotation at 8 knots.
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
Presentation 19th ICMCF 26-6-2018
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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.
Left: at start of release test; Middle: 5 min rotation at 8 knots; Right: 3 hrs rotation at 8 knots.
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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
Presentation 19th ICMCF 26-6-2018
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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
Presentation 19th ICMCF 26-6-2018
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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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Fouling release after 2nd static ageing period
Panels (4 months D, 10 weeks S, 5 months D) 7 weeks static at 120 cm depth
At the start After 5 min After 60 min After 180 min
Paint 3
Paint 8
Paint 1
Presentation 19th ICMCF 26-6-2018
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Fouling release after 2nd static ageing period
Panels (4 months D, 5 weeks S, 5 months D) 14 weeks static at 30 cm depth
At the start After 5 min After 60 min After 180 min
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.
Presentation 19th ICMCF 26-6-2018
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Thank you very much for your attention
[email protected] +31 6 10490059