Updates to Rapid Cure Technologies for Field Repair

1
Updates to Rapid Cure Technologies for Field
Repair
2006 Air Force Corrosion Program Conference 16
March 2006

• Mr. Corey Bliss
• AFRL/MLSSO
• Coatings Technology Integration Office

2
Overview

• Background
• 24-Hour APC Cure
• Brush/Roller Quick Cure
• Two-Component Aerosol Quick Cure
• Plural Component Spray Equipment
• Ultraviolet (UV)-Curable Coatings

3
Background

• Currently, T.O. 1-1-8 says
• (Para. 6-20) Aircraft shall not be operated until
  72 hours has elapsed at a temperature of 75º F or
  higher, after the topcoat application is
  completed.
• (6-20.7.1) Complete leading edges (All), complete
  control surface (All), major skin panels 9 square
  feet and over, and engine intake, 72 hours
  minimum.
• (6-20.7.2) Skin panels less than 9 square feet,
  fasteners, rivet heads, screw heads, and minor
  chipped and scratched areas, less than 36 square
  inches, 30 hours minimum.

4
Background

• AFRL has initiated several RD projects to
• Reduce overall dry-to-fly time
• Reduce dependency on temperature humidity
• Help eliminate wasted coatings products
• Reduce cost time needed for equipment
  maintenance
• Maintain a high level of coatings performance
• Minimize the need for a large new capital
  investment

5
24-Hour APC Cure

• Performance evaluation of Defts Extended Life
  Topcoat (ELT) after 24-hr cure
• Boeing data CTIO data were consistent w/each
  other
• Adhesion
• Fluid resistance
• Flexibility
• But, the coating is very soft at 24-hr cure
• T.O. 1C-17A-23 was modified to reflect the
  acceptability of 24-hr dry-to-fly
• One C-17 at McChord tested 24-hr cure and 72-hr
  cure head-to-head and showed no apparent problems

6
24-Hour APC Cure
7
Brush/Roller Quick Cure

• Description Modification of Defthane ELT and
  MIL-PRF-23377H Hentzen topcoat and primer
  formulations for hand application by either a
  brush or roller. In addition, exploration of
  accelerator modifications to decrease cure time
  and allow a lower temperature cure environment
  (40F goal).

8
Brush/Roller Quick Cure

• Objectives
• Full coating stack dry-to-fly within 12 hours (24
  hrs. threshold)
• Identify optimal application procedures and
  equipment
• Maintain all 23377 and APC requirements
  especially appearance!
• Advantages
• Ability to paint repair areas of lt200 sq. ft. in
  the field
• Faster turnaround for increased mission readiness
  survivability
• Reduced logistical footprint and increased
  painting opportunities
• Status
• Proper film build topcoat appearance difficult
  in first trials. Examining alternative solvents
  and thixotropic additives to provide adequate
  film build and leveling. Accelerators have been
  identified that reduce cure time, but have
  shorter pot-life.

9
Two-Component AerosolQuick Cure

• Description Utilizing 2K aerosol technology for
  fast and convenient touch-up of both
  MIL-PRF-23377H primer and APC grade topcoat. Fast
  curing possible with additional accelerator
  present in formulations.

• Same paint as used in HVLP guns
• Pot life starts when can is activated
• Spray pattern similar to HVLP
• As convenient as using regular spray paint

10
Two-Component AerosolQuick Cure

• Objectives
• Full coating stack dry-to-fly within 12 hours (24
  hrs. threshold)
• Maintain all 23377 and APC requirements
• Advantages
• Ability to repair small areas in deployed
  locations
• Faster turnaround for increased mission readiness
  survivability
• Fast and ultra-convenient with simple set-up and
  no clean-up
• Status
• Development of aerosol version of Akzo-Nobel
  Aerodur (PD-5000) topcoat and 23377 primer
  completed. Modification of formulations for
  reduced cure time through use of accelerators
  currently in progress and expected to be complete
  by May 2006, followed by field evaluation.

11
Plural Component Spray Equipment

• Description
• Spray equipment that mixes components A B
  immediately prior to atomization

12
Plural Component Spray Equipment

• Objective
• Achieve dry-to-fly in 12 hrs or less using the
  same equipment for both primer topcoat, with
  minimal additional training and small capital
  investment
• Advantages
• Equipment is inexpensive and easy to maintain
• Status
• AMC has identified 4 bases for a one-month field
  trial CTIO is awaiting equipment upgrade from
  PPG ( Apr 06)

POC Charles Griffin, CTIO, DSN 785-3107
13
UV-Curable Coatings

• Description Coatings designed to cure when
  exposed to ultraviolet radiation of specific
  wavelength

Source Ultraviolet (UV) Cure Safety, Quality
and Speed for Refinishing CD ROM from RadTech
14
UV-Curable Coatings

• Objective Match performance of APC reduce
  dry-to-fly time below 12 hours, perhaps as low as
  several minutes
• Advantages Low/No VOC VERY rapid cure (Approx.
  2 to 20 min) long pot life maybe single
  component
• Drawbacks Must match radiation source w/coating
  requires additional equipment (radiation source),
  training, safety measures other important
  issues, such as lamp system design, curing
  shadowed areas, and ensuring complete cure are
  still being worked by AFRL
• Status There are currently 4 RD projects for
  OML applications AFRL developed performance
  requirements for primer, topcoat, and complete
  system P2 has identified this technology as
  promising candidate for tech transition

15
Status Summary

• 24-Hour APC Cure
• Effort complete T.O. 1C-17A-23 was changed
• Brush/Roller Quick Cure
• RD effort ongoing
• Two-Component Aerosol Quick Cure
• Ready for field test in May 06
• Plural Component Spray Equipment
• Ready for field test Apr 06
• Ultraviolet (UV)-Curable Coatings
• RD effort ongoing CTIO testing in late FY06

16
Contact Info

• Corey.Bliss_at_wpafb.af.mil
• [phone], DSN 785-0943
• www.ml.afrl.af.mil/ctio