GENTOO Tenchical Presentation

1. DURABLE HYDROPHOBIC COATING
FOR CORROSION PROTECTION & EASY CLEANING

2. WHAT IS GENTOO?
A novel coating that is:
• Clear
• Durable
• Abrasion and chemical resistant
• Corrosion barrier
• Named after a penguin

3. DURABLE RAIN REPELLENT COATINGS
FOR AIRCRAFT
US Air Force and US Navy (NavAir)
• Hydrophobic, durable rain repellent coating
• Superior shedding of water for improved pilot
visibility under inclement weather conditions
• NavAir - F-35 in 2010; Air Force – F-16 in 2015

4. DURABLE COATINGS FOR CORROSION
PROTECTION OF LANDING GEAR
US Air Force
• Superior corrosion protection/reduced
foreign object debris damage compared to
current MIL spec paints
• Can be applied over existing surface
treatments and coatings to extend service
• Thin, durable and flexible
• Phase II started in 2016

5. BARRIER COATINGS FOR REMOTE
MINEHUNTNG TOW CABLE
US Navy (NavSea)
• Corrosion Resistant, watershedding
coating
• Stainless steel tow cabe employed on the
Remote Minehunting System (RMS)
• Program started in 2014

6. KEY ATTRIBUTES
• Chemical Resistance and Watershedding
• Transparency
• Corrosion Protection
• Flexibility
• Abrasion Resistance and Durability

7. KEY ATTRIBUTES
• Sol-gel – two-step chemical reaction to create hydrophobicity
and corrosion resistance
• Very thin – only 4-6 microns thick in most applications
– Adds very little weight to coated substrate
• Works in operating temperatures from -50°C to 200°C

8. HYDROPHOBICITY
Contact angle Watershedding
(120 µl)
Watershedding
(50µl)
Steel 63 >45 >45
Aluminum 60 >45 >45
Polyurethane (MIL PRF 85285) 95 15 30
Acrylic 68 18 21
Polycarbonate 77 14 13
Gentoo 110-117 3-5 7-11
Gentoo leaves little to no trail of water, whereas all uncoated substrates leave a
significant trail
ASTM D7334 Testing

9. WATER SHEDDING

10. FLUID IMMERSION
• Glass slides coated with Gentoo – exposed to fluids for 48 hours and then tested
for water contact angle

11. FLUID IMMERSION
• Hydrophobicity is maintained for all but one solvent after 48 hour exposure
Uncoated
Gentoo
Solvents Tested
1. Mild soap (20 vol. % in water)
2. Salt water (5 wt. %)
3. IPA (50 vol. %)
4. IPA (90 vol.%)
5. Naptha
6. Heptane
7. Jet fuel (JP8)
8. Deicing fluid (100% Propylene glycol)
9. Hydraulic fluid (MIL-H-83282)
10. Hydraulic fluid (MIL-H-05606)
11. Lubricant (MIL-L-23699)
12. Lubricant (MIL-L-7808)
13. Lubricant (DOD-L-85734)
14. Polyalphaolefin coolant (MIL-PRF-87252C)
15. Navy plastic polish (P-P-560, Type 1)
16. Airplane wash cleaner fluid (MIL-C-8514) – VERY acidic
17. Alodine 1201 wash and rinse (MIL-DTL-81706)

12. ICE ADHESION TESTING
Gentoo coating significantly decreases ice adhesion by almost 5x, lowering
time/cost of de-icing operations
Surface Ice Adhesion (kPa)
Polyurethane coating on steel 641
Gentoo coating on polyurethane coating on steel 305
Gentoo coating directly on steel 130
Testing performed at -15°C

13. TRANSPARENCY AND HAZE
Transparency Haze
Bare acrylic 94.0 0.69
Gentoo coating on acrylic 94.0 0.4
Bare glass 94.0 0.9
Gentoo coating on glass 94.1 0.2
Minimal change in transparency
or haze on different substrates
Transparency and Haze per ASTM
D1003 and ASTM D1044-13 with Byk-
Gardner Haze Guard Plus meter
F-16 Canopy

14. CORROSION – GALVANIC FASTENER
• Applying Gentoo on top of traditional anti-
corrosion surfaces further enhances the
corrosion resistance of the material.
• Dissimilar fastener assemblies painted
with top coat and then coated with
Gentoo
• Exposed to Salt Fog (ASTM B117) for 1,340
hours

15. CORROSION – GALVANIC FASTENER
Description
Average
Weight Loss
(%)
Average Pit
Depth (mm)
Bare fasteners;
control panel
2.2 120
Bare fasteners;
Gentoo panel
1.6 100
Gentoo fasteners;
control panel
0.5 78
Gentoo fasteners;
Gentoo panel
0.1 40
Bare fasteners and panel;
Gentoo applied post-
assembly
0.35 90
0
30
60
90
120
150
0.0
0.5
1.0
1.5
2.0
2.5
Bare fasteners;
control panel
Bare fasteners;
Gentoo panel
Gentoo fasteners;
control panel
Gentoo fasteners;
Gentoo panel
Bare fasteners &
panel; Gentoo post
assembly
AveragePitDepth(µm)
AverageWeightLoss(%)
Average Weight Loss Average Pit Depth (μm)
65-75% Reduction in weight
loss with hydrophobic coating
FastenersSolventStripped648hrinB117

16. CORROSION –CREVICE CORROSION
• Stainless steel coupons
– One bare, one with Gentoo
• Two PTFE crevice washers
against each face of
stainless steel coupons
• Coupons were scribed on
each side to represent
heavy damage from over
torqued fasteners

17. CORROSION –CREVICE CORROSION
Samples immersed in acidified ferric chloride
for five days at room temperature
0
1
2
3
4
5
6
7
8
9
Bare uncoated Luna
%MassLoss
Bare uncoated Gentoo
Gentoo-coated coupons had significantly lower mass loss
Per ASTM G48-11

18. CORROSION – SALT FOG (ASTM B117)
Before Salt Fog After 571 Hours
Contact Angle (°) 112 110
Transparency (%) 92 92
Haze (%) 0.8 0.6
Clarity (%) 99.8 99.7
Gentoo Coating is essentially
unchanged after 571 hours of
salt fog exposure.
Transparency, Haze, and Clarity per ASTM D1003 and ASTM D1044-13 with Byk-Gardner Haze Guard Plus meter
Gentoo was applied to polycarbonate and exposed to
ASTM B117 salt fog testing for 571 hours

19. CORROSION – ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY
• This test is used to evaluate
barrier properties
• Aluminum 2024 with MIL-
spec polyurethane then
coated with Gentoo
• Testing was done initially and
after 336 hours of Salt Fog
(ASTM B117)
• Gentoo Coated sample
shows improved barrier
properties after salt fog
Polyurethane + Gentoo (dry)
Polyurethane + Gentoo (336 hrs)
Polyurethane (dry)
Polyurethane (336 hrs)

20. CORROSION – FOREIGN OBJECT DEBRIS
Panels of zinc/nickel plated steel were tested two ways:
1. Coated directly with Gentoo
2. Painted with a two-part epoxy/urethane and then coated with Gentoo
Controls were used to test the impact of the Gentoo

21. CORROSION – FOREIGN OBJECT DEBRIS
• The panels were then subjected to the foreign object
debris, using compressed air to shoot gravel at the
samples
• After this, the panels were tested with salt fog (ASTM
B117) for 2,136 hours (~13 weeks)
• Panels were observed for corrosion and then stripped
of all coatings to observe the effect on the bare metal
• Panels were scribed

22. CORROSION – FOREIGN OBJECT DEBRIS
• Top panels are Gentoo
over system
• Bottom Panels are just
the system
• Left panels are straight
from Salt Fog
• Right Panels are after
stripping all coatings

23. CORROSION – FOREIGN OBJECT DEBRIS
• Gentoo improves protection of
substrate from salt fog
exposure as a function of
impact
• Control panels have more large,
deep impacts to substrate
• Gentoo coated have superficial
impacts, not inherent corrosion

24. FLEXIBILITY
Gentoo on bare aluminum Gentoo on top of MIL-spec
polyurethane on aluminum
1
8” Mandrel Tests – no signs of cracking or crazing in the Gentoo

25. FLEXIBILITY
Gentoo on bare aluminum 52oC Gentoo on bare aluminum at -51oC
1
2” Mandrel Tests – no signs of cracking or crazing in the Gentoo

26. DURABILITY – PENCIL HARDNESS
• ASTM D3363 - determine the resistance to
surface scratches
• Hardness of the substrate matters because
Gentoo is so thin and flexible
• Gentoo results:
– 9H on hard surfaces
– 5H on softer surfaces

27. RECIPROCAL ABRASION
• Glass coupons
• ASTM D2486 using 316 steel wool for 150 cycles
• Compared with Ultra-Ever Dry (Commercial 1) and military water repellant (Commercial 2)
Bare
Glass
Gentoo
As cast Abraded
Commercial 1
As cast Abraded
Commercial 2
As cast Abraded

28. RECIPROCAL ABRASION
• Stainless Steel coupons
• ASTM D2486 using 316 steel wool for 150 cycles
• Compared with Ultra-Ever Dry (Commercial 1) and military water repellant (Commercial 2)

29. RECIPROCAL ABRASION
• Stainless steel coupons
• ASTM D2486 using Scotch Brite pads and 200g weight
• Compared with Ultra-Ever Dry
• Gentoo holds up much better to abrasion cycles
Gentoo
Ultra-Ever Dry

30. TABER ROTARY ABRASION
• ASTM D4060 – 500 Cycles using CF-10F wheels
with 500g weight on each wheel
• Substrate is polycarbonate
Initial After Taber
Haze
Contact
Angle
Watershed
Angle
Haze
Contact
Angle
Watershed
Angle
Gentoo 1.2% 113.2° 9.0° 6.0% 108.4° 13.8°

31. OSCILLATING SAND ABRASION
• Bayer Abrasion – ASTM F735
• Sand used to abrade clear plastics
• Substrate is polycarbonate
0 Strokes 600 Strokes 2000 Strokes

32. OSCILLATING SAND ABRASION
Gentoo is still
hydrophobic after
2,000 oscillations Uncoated
Gentoo

33. UV EXPOSURE
• Gentoo can be degraded with long exposures to UV
• If the substrate contains a UV stabilizer in it (such as
some plastics) or on it (such as clear coat or paint with
UV stabilizer), the Gentoo will last much longer
(potentially for a number of years)
• Without a UV stabilizer, the Gentoo may only last a few
months
• Development of a UV stabilizer to be incorporated into
the Gentoo is currently underway

34. STABILITY WITH UV EXPOSURE
• QUV testing
• ASTM 4329
• 500 hour exposure
• Bare acrylic
• Acrylic coated with Gentoo
Bare acrylic
Gentoo coating on acrylic

35. STABILITY WITH UV EXPOSURE
• QUV Testing
• ASTM 4329
• UVB bulb
• 672 Hours (4 weeks)
• Cycle:
– 7 hours of UV at 50°C
– 5 hours at 100% humidity at 50°C
• Bare polycarbonate
• Polycarbonate coated with Gentoo
0 weeks 1 week 2 weeks 3 weeks 4 weeks
Uncoated QUV Exposure
0 weeks 1 week 2 weeks 3 weeks 4 weeks
GentooTM QUV Exposure

36. STABILITY WITH UV EXPOSURE
• Polycarbonate samples from previous slide
• Repellency remains high after QUV exposure
Uncoated
Gentoo

37. GENTOO – EXCELLENCE IN CORROSION
PROTECTION & EASY CLEANING
• Chemical resistant – sheds water and fluids well
• Excellent adhesion, environmental stability
• Improved abrasion resistance
• Excellent barrier for improved corrosion
resistance

38. THANK YOU