The Department of Defense (DOD) has been utilizing laser and automated paint removal technologies as alternative processes to traditional paint/coating removal methods. These new technologies have demonstrated the ability to reduce costs, reduce waste, improve safety, and increase weapon system readiness. The DoD’s validation and continued development of laser coating removal systems has resulted in the technology moving from limited, niche applications to engineered systems using commercial, off-the-shelf components that are reliable, easy to maintain, and being used for mainstream applications. This forum will include briefings from the US Air Force on the advancements of their laser coating removal program, updates on their full aircraft robotic paint removal program, an update from NAVAIR on their rotor blade laser de-painting operation at Fleet Readiness Center-East, a discussion form Keyport NUWC on their laser ablation program, and finally, Boeing will describe their handheld laser ablation technology.
1300-1305: Welcome, Intro & Purpose – Greg Kilchenstein, OSD-MR
1305-1309: Administrative Notes – Debbie Lilu (NCMS)
1309-1330: F-16 Robotic Laser Ablation – Rik Crowther (USAF) Presentation
1330-1350: Robotic Laser Coating Removal at WR-ALC – Shane Groves (WR-ALC)
1350-1410: Automated Rotor Blade Stripping System (ARBSS) Update – Chase Templeton (FRCE)
1410-1430: Boeing Handheld Laser Ablation – Kady Gregersen (Boeing) Presentation
1430-1450: Laser Ablation at Keyport – Steve McKee (NUWC Keyport) Presentation
1450-1500: Wrap-Up – Greg Kilchenstein (OSD-MR)
Event: On 30 March 2021, the Joint Technology Exchange Group (JTEG), in coordination with the National Center for Manufacturing Sciences (NCMS), hosted a virtual forum on “Laser Coating Ablation”.
Purpose: The purpose of this forum was to examine and share information on laser ablation capabilities available to the DoD maintenance community. The forum provided descriptions of capabilities employed by the military Services as well as programs from both academia and industry.
Welcome: Greg Kilchenstein (OSD-MR) welcomed everyone to the forum and thanked the presenters and all the listeners for their attendance. He also stated how important laser ablation is in driving sustainment costs and readiness in the DoD maintenance community and how its’ adoption within DoD has expanded over the years.
Administrative: This was an open forum. The presentations, along with questions and answers, were conducted through Adobe Connect. Some of the presentations were available online at the JTEG website at http://jteg.ncms.org/ during the brief. A separate audio line was used. We had over 100 participants from across DOD, industry, and academia join in the forum.
F-16 Robotic Laser Ablation. Shane Groves capably stood in for Rik Crowther who was unavailable. Shane described the differences between plastic media blasting and the Ogden Air Logistics Complex’s (ALC) robotic laser coating removal system (RLCRS), highlighting the significant reductions in waste material and manhours, and the ability to remove the worker from a hazardous environment. Ogden ALC is currently working with Lockheed Martin, the F-s5 SPO and others to explore other capabilities and benefits.
Robotic Laser Coating Removal at WR-ALC. Shane Groves (WR-ALC) compared the current FlashJet depaint method with the desired Robotic Laser Depaint process describing the pros and cons of each and explaining how the newer capability must undergo many tests before approval to use is granted. He described the laser generator and the laser focusing optics, then showed a video of the robotic laser depaint process in action, before ending with a list of SPOs they are currently working with.
Automated Rotor Blade Stripping System (ARBSS) Update. Chase Templeton (FRCE) described the background of ARBSS being used to strip paint on refurbished rotor blades, to include acceptance and challenges. He then discussed upgrades to include the lasers and software, and explained the process recipe and color recognition. He followed with a description of final acceptance testing to include photographs of the results, before concluding with a mention of future work with V-22 and H-1 Blades.
Boeing Handheld Laser Ablation – Kady Gregersen (Boeing) talked about Boeing’s commitment to environmental leadership and safety in the workspace. She highlighted laser ablation versatility and established facilities, before describing how using lasers and a closed-loop feedback improves quality and protects substrates. She provided information on qualification and production trials noting that four production trials are complete. The technology is currently TRL 8 and Boeing is working on operator assist tools to further improve rate and quality.
Laser Ablation at Keyport – Steve McKee (NUWC Keyport) described the program’s intent as the transition of laser ablation technology to NAVSEA maintenance organizations and requirements for the procurement and sustainment to include material/system selection, training, and safety. He revealed testing results and showed examples to include environmental testing, and laser ablation equipment, followed by the description of an operational demonstration of the laser ablation equipment to include feedback and lessons learned, before finishing with the path forward.
Q&A – A Q&A occurred after each briefer finished their presentation. Questions and answers will be posted on the JTEG website with these minutes.
Closing Comments: Greg Kilchenstein thanked the presenters for their contributions and all the work being done to support laser coating ablation efforts across the DoD, academia, and industry. He suggested continuing the information exchange beyond the forum and the importance of collaboration within the DoD maintenance community.
- Obtain copies of the presentations once they are approved to post to a public website, and post to the JTEG website at http://jteg.ncms.org/.
Next JTEG Meeting: The next scheduled JTEG virtual forum is 27 April 2021, 1:00 – 3:00 pm EST. The topic is “Energy Resilience”.
POC this action is Ray Langlais, firstname.lastname@example.org, (571) 633-8019
F-16 Robotic Laser Ablation – Shane Groves for Rik Crowther (USAF)
Q1. You spoke of the limited number of times that PMB can be used to strip F-16 paint, is there a limit to the number of times that laser ablation can be used on F-16? Does laser ablation have the benefit of extending aircraft skins?
A1. No limit. Yes, laser ablation extends aircraft skins.
Q2. Are you stripping composites?
A2. Not today. WRAFB will be with our system, but are still testing for air worthiness. Mostly carbon fiber.
Q3. Do you see a difference between primers for strip-ability?
A3. The lighter the color, the more difficult.
Q4. How much programming was required to set up the robots on the F16 geometry
A4. That’s a challenging question. 100% is model based. No programming is required. It does require time to build a model.
Q5. How much operator oversight is required to manage the robots?
A5. The operator has real-time feedback using cameras and sensors and receives a “cartoon view”. The operator “gives permission” to any changes.
Q6. Are you looking at a laser reflective intermediate coating?
A6. That would be nice. We do not have it.
Q7. Is the system limited to F-16? or could it be used on another F-16 size aircraft?
A7. If it fit in the bay, we could use it. We would need to create a model.
Q8. How did you create the 3D models? Was it all generated from scratch?
Q9. How much waste material does the laser process save? X # of lbs vs 10-12 lbs?
A9. Laser waste is 10-12 lbs for the entire F-16, vs 2,000 lbs using PMB.
Q10. Are you looking into additives for organic coatings to make laser stripping easier?
A10. I am not. That would be a System Program Office action.
Q11. How much room under the aircraft does the system need to strip the undersides?
A11. If you go to slide 5 there is a photo. I’d say approximately 5-6 ft.
- Has the laser been approved for stripping from honeycomb sandwich structure?
A12. Not yet, but I am working with the C-5 and C130 program offices.
Robotic Laser Coating Removal at WR-ALC – Shane Groves (WR-ALC)
Q1. How dimensionally accurate is the virtual masking feature?
A1. Very to a certain aspect. It divides the model into 1 cm squares.
Q2. What’s the greatest challenge toward flight worthiness for laser ablation?
A2. IMO, it is new and what it does to the parts is unknown. There is a concern about damage possibilities because of the lack of historical data.
Q3. How does this system differ from the older system that did the strip by spinning the dome horizontally?
A3. I am unfamiliar with that system. Compared to flash jet, I hand program vs 1.5 minute on the model.
Q4. How much coating is left on the radome after stripping? Is it even or is it stripped to substrate?
A4. Stripped to the primer. The goal is to not hit the substrate. The primer is removed with sanding. Our aim is to also make it robotic.
Q5. Do you have a template for business cases that interested parties can leverage to make business decisions?
A5. We can provide approximate time savings. We cannot show BCA outside the government. Our results show it is twice as fast as the flash jet process.
Q6. What type of substrate testing is required to receive air-worthiness?
A6. We typically deal with SPOs directly. We don’t deal with airworthiness. I can’t speak to what tests are required.
Q7. If you don’t have the part model, do you have to develop one or can the system self-generate a geometric model that is “good enough”?
A7. We always generate our own. The problem with system generated is that you need a starting point.
Q8. Follow on question: Are there any transmittibility concerns in regards to leaving the primer due to paint build up?
A8. Yes. The radome has to be as invisible as possible, i.e. a “see-thru” window. Primer must be in the specification.
Q9. Can you please repeat the name of the robotic system you are using?
A9. Titan Robotics System
Automated Rotor Blade Stripping System (ARBSS) Update – Chase Templeton (FRCE)
Q1. How many total articles have you processed?
A1. I don’t have a quantity. We have multiple blades.
Q2. What is the current production through-put for ARBSS for the various rotor blades you strip?
A2. H53E main rotor blades are the only ones in current production. It is a relatively low percentage.
Q3. Were there any cultural challenges to get the ARBSS operational? Do they continue today?
A3. Yes, and we still have them. There is a reputation with reliability based on earlier tests and uses. Also, it is not a requirement to use. It is up to the supervisors to recommend.
Q4. is there any critical concern of heat transfer/ heat retention into the substrate you are working that could potentially compromise the material?
A4. No, not in my mind, because we stop at the primer.
Q5. How difficult is it for the system to tell the Black 85285 topcoat from the Type II dark green primer?
A5. It is very easy. We can set the red-green filter.
Q6. Please elaborate on the nature of maintenance challenges. Can these be overcome?
A6. Partially cultural, and part of it is the lead time for parts. Yes, with time.
Q7. Are the V-22 and H-60 rotor blade ARBSS business cases compelling enough to the PMs to obtain the resources necessary to complete the qualification testing outstanding?
A7. They are not cheap. It is a challenge to procure the funding.
Q8. Why is ARBSS only used 10% of the time for H-53 blades?
A8. Mainly set-up time. If a small area, hand sanding is quicker. It is up to the discretion of the supervisor.
Q9. Can the ARBSS be used to strip other coatings, such as elastomeric rain-erosion coating?
A9. I’m not familiar with that coating. We don’t use it with rubberized coatings. They gum things up.
Q10. Is there any work being done with composite manufacturers to conform the resins for laser processing?
A10. I have not heard of anything going on with that.
Q11. What is the processing time savings when stripping a blade compared to manual processes? Would co-locating the processes in the same facility enable you to use it more extensively?
A11. I don’t have the exact figure. If we can get workers out of a hazardous environment, we are for it.
Boeing Handheld Laser Ablation – Kady Gregersen (Boeing)
Q1. What does Boeing see as the most beneficial aspect of laser ablation over traditional methods? time, safety, hazmat reduction, substrate damage?
A1. Safety. Really, all I would say is Safety.
Q2. What are the power requirements of the system? Can it be put in a battery backpack?
A2. Not at this time. Very long umbilical cord.
Q3. Are there any safety features on the laser itself?
A3. A couple. There is an ergonomic pin that if your finger is off the pin, it will not fire. Also, there is an arming switch.
Laser Ablation at Keyport – Steve McKee (NUWC Keyport)
Q1. What work has been done with combat and comm system radar composite structures? I’m referring to structures such as radomes and antennas that are complex structures and tend to be thin (composite laminate sections).
A1. Generally, no work has been accomplished on combat/comms systems composite structures. There is a recognition that this analysis needs to be performed, but to date, we do not know of any analysis for these types of substrates.
Q2. What was the substrate that the paint blisters were on?
A2. Nick Bankus: I am assuming that the ‘paint blisters’ refer to the Cathodic disbondment testing. In which case, the substrate was ASTM A1008/1011 (Cold Rolled/Hot Rolled) carbon steel.