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When Murphy paints an airplane
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When Murphy Paints an Airplane
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,
)
,
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by Kate Kubernach KMR Consulting
S
Inc., Seaford,
Vu.
ometimes at the start of a job, everything looks normal and you never think that things can go wrong. You are doing something that you have done a thousand times before, have a lifetime of experience, and all of a sudden the project turns south in a big way. That is because Murphy (not the Editor) has arrived and decided that your shop looks like a great place to take up residence. The following is a true story of how things can go wrong when you think you are doing everything right. Murphy’s paint job started in May 2001 in a small town in west Texas. The aircraft being refurbished was a T-38A Talon destined for a local aviation museum. The aircraft was obtained from the “boneyard” in Tucson, Ariz., and came to Texas missing several panels and pieces important to the overall appearance of the aircraft. It was soon obvious that this would not be an ordinary refurb project. The plane was still coated in a protective rubber-type coating on the canopy, intake, and exhaust areas. It had been sitting in the boneyard for over 10 years and needed lots of tender loving care to restore it to its prior active condition. The facility we had to do this job was not what anyone would call “state of the art.” The two best things about the place were that the lighting was great and it was indoors. Ventilation was good if the wind was blowing and fortunately, in west Texas, the wind is always blowing. This shop was actually better than some we had worked in. The project started in late May with the removal of the storage coating and decals, and soon we were sanding off all the old markings and paint. Ideally, we should have blasted off all the coating but had no way to get that accomplished so sanding was our only option. Once the sanding was completed, we had to manufacture panels to replace those that were missing. A real challenge developed when we couldn’t obtain a tail cap. Through lots of trial and error, with no structural maintenance shop at our disposal, we finally fashioned a tail cap out of steel sheets, plywood, and Bondo. Good thing that this plane would never fly again and was only for show! The day we set for painting was perfect in every way, ideal humidity and temperature. Everything to 14
this point had gone pretty much as anticipated until we mixed our first batch of coating. We used a standard two-component gloss white polyurethane that we planned on shooting with a pressure pot system and HVLP gun. The coating mixed as advertised and was put into the pressure pot. This is when Murphy first showed his ugly side. The equipment, which had previously worked perfectly and was nearly new, refused to spray at all. We changed guns, hoping that would fix the problem. Three guns later we finally had an operating set-up. By now, the coating had been mixed for about 30 min. Because of the ambient temperature we felt we needed to recheck viscosity before spraying and possibly thin it some. We added thinner and immediately had a mess on our hands. The coating turned to Jell-O and we had to dump two gallons out on the spot. Figuring that we had used the wrong thinner, we checked the manufacturer’s instructions and saw that we had done everything right, so we mixed a second smaller batch to see if we got the same results. Unfortunately, we did, and we put off painting until we got an answer to the problem. It turned out that the coating was warm, the thinner was cold, and we created a mess. A few days later, we obtained an entirely different product and set about again to coat the aircraft. We decided to paint with an airless system. The belly of the aircraft came out beautifully, but when we reached the topside, all hell broke loose. The coating would go on beautifully then within about 30 seconds start to pinhole and fish eye. Knowing the amount of surface preparation we had put into this aircraft, we were amazed at the sudden turn of events. We had no choice but to stop, let the coating dry, and resand the areas we had sprayed. The next day we applied a primer/sealer with good results and got ready once again to apply the topcoat. So there we were with new coating, good equipment, and ready to go. We mixed the coating, pressurized the pot, and started to spray. We got about 5 minutes of good spraying when we started having trouble with the paint. It was thick and would not atomize properly so we again stopped to see what was going on. We opened the pressure pot to find that the paint had already set up and was almost Metal Finishing
100% cured! Did you know that there is no way you can get cured paint out of 75 feet of fluid line? It also does a real number on paint guns and pressure pots! By this time, we were pretty fed up with the whole process and called the manufacturer. The unused coating was returned for analysis and we later learned that during the manufacturing process, a decimal point had been moved and instead of 1% of a curing agent, there was 100%. Hey, worked great but nb pot life! We were then almost 3 weeks into a project that should have taken no more than 10 days and decided to walk away from it for a few months. Thinking that time away and a fresh start 3 months later may turn our luck around, we left the aircraft in that condition and made plans for a fall return. It was now mid-September, the summer heat was gone, and we were ready to tackle the project. Our crew met up; we again sanded off the bad coating, and were right on schedule. Three days into it, we were ready to paint once again. Beautiful weather conditions, equipment that had been checked out, and coating that had been pretested for usability. What could go wrong? Murphy, that’s what! Obviously, he liked his living conditions in the hangar and decided to stay. We did a prepaint wipe-down and thought everything was fine. We started to spray and had immediate failures with pinhole/cratering. By now, we were all ready to pull out hair. We went through the list of what could have gone wrong, like contaminated thinner used during wipedown, dirty cloths, oil in the airline, contamination of the equipment, or coating or environmental contamination. We changed out equipment, swapped out our air source, got new thinner and cloths, and tried to eliminate any potential contamination sources. Everything checked out, so we were now again facing a real problem. The deadline for the unveiling of this plane was only 12 days away and we were no closer to a finished product than we were in June. This is when we started grasping at straws. There was a coating manufacturer in town that we were familiar with and turned to them for help. They have a lab on site so we stripped some coating from the aircraft to look at under a microscope. It turns out that the protective coating that was used over 10 years ago at the boneyard had soaked into the paint system and while we thought we were sanding it off, we were actually driving it deeper into the coating surface. Short of stripping the aircraft to bare metal, we were in a no-win situation. The local manufacturer had an epoxy-based March 2002
Figure 1. T-38 jet aircraft, used by the Air Force for pilot training, in the final stages of refurbishment.
ceramic coating that is one of the most forgiving paints I have ever seen and we were given some to try as a “barrier” coat. By now, we are all “gun shy” but decide to give this a chance. The coating went on and did not pin hole, so we shot the plane with it and let it dry. We actually had a paintable surface to work with 24 hours later. Two days
Figure 2. The tail cap was completely markings were applied.
rebuilt and is shown after
15
BIOGRAPHY Kate Kubernach is President of KMR Consulting Inc. She has been painting aircraft for 30 years. KMR Consulting Inc., located in Seaford, Va., and Las Vegas, provides training in paint applications with heavy involvement in the military and aviation industry. MF
later, the plane was white and glossy and we put the markings on. (See Figs. 1 and 2.) With 6 days to spare, we closed up shop and turned the plane back to its rightful owners. We know that Murphy has now moved on, but since he left no forwarding address, it is anybody’s guess as to where he may turn up next.
Nickel and Chromium Plating, Third Edition by /. K. Dennis and 7X Such
449 pages $155 .OO
In this book the authors describe the industrial processes for carrying out nickel and chromium plating. New material reflects the move from purely decorative and corrosion protection of mass produced articles to surface engineering of more valuable products. Updated throughout, new material of particular interest appears on environmental and health concerns, electroless nickel, electroforming, and alloy deposition. Send Orders to: 650 Avenue of the Americas, New York, NY 10011 For faster service, call (212) 633-3199 or FAX your order to (212) 633-3140
METAL FINISHING:
All book orders must be prepaid. Please include $5.00 shipping and handling for delivery of each book via UPS in the U.S., $10.00 for each book shipped express to Canada;and $20.00 for each book shipped express to all other countries.
With’
l
A
CIear
Solution
l Closed Loop Recycle Process Specific Engineering l Turnkey Systems
dromatix.com Circle 066 on readercard 16
l
or go to www.thru.to/webconnect Metal Finishing
When Murphy Paints an Airplane
..A” r, ,W$%,,e , a..
.
r; /,..,/,.
,
)
,
,
by Kate Kubernach KMR Consulting
S
Inc., Seaford,
Vu.
ometimes at the start of a job, everything looks normal and you never think that things can go wrong. You are doing something that you have done a thousand times before, have a lifetime of experience, and all of a sudden the project turns south in a big way. That is because Murphy (not the Editor) has arrived and decided that your shop looks like a great place to take up residence. The following is a true story of how things can go wrong when you think you are doing everything right. Murphy’s paint job started in May 2001 in a small town in west Texas. The aircraft being refurbished was a T-38A Talon destined for a local aviation museum. The aircraft was obtained from the “boneyard” in Tucson, Ariz., and came to Texas missing several panels and pieces important to the overall appearance of the aircraft. It was soon obvious that this would not be an ordinary refurb project. The plane was still coated in a protective rubber-type coating on the canopy, intake, and exhaust areas. It had been sitting in the boneyard for over 10 years and needed lots of tender loving care to restore it to its prior active condition. The facility we had to do this job was not what anyone would call “state of the art.” The two best things about the place were that the lighting was great and it was indoors. Ventilation was good if the wind was blowing and fortunately, in west Texas, the wind is always blowing. This shop was actually better than some we had worked in. The project started in late May with the removal of the storage coating and decals, and soon we were sanding off all the old markings and paint. Ideally, we should have blasted off all the coating but had no way to get that accomplished so sanding was our only option. Once the sanding was completed, we had to manufacture panels to replace those that were missing. A real challenge developed when we couldn’t obtain a tail cap. Through lots of trial and error, with no structural maintenance shop at our disposal, we finally fashioned a tail cap out of steel sheets, plywood, and Bondo. Good thing that this plane would never fly again and was only for show! The day we set for painting was perfect in every way, ideal humidity and temperature. Everything to 14
this point had gone pretty much as anticipated until we mixed our first batch of coating. We used a standard two-component gloss white polyurethane that we planned on shooting with a pressure pot system and HVLP gun. The coating mixed as advertised and was put into the pressure pot. This is when Murphy first showed his ugly side. The equipment, which had previously worked perfectly and was nearly new, refused to spray at all. We changed guns, hoping that would fix the problem. Three guns later we finally had an operating set-up. By now, the coating had been mixed for about 30 min. Because of the ambient temperature we felt we needed to recheck viscosity before spraying and possibly thin it some. We added thinner and immediately had a mess on our hands. The coating turned to Jell-O and we had to dump two gallons out on the spot. Figuring that we had used the wrong thinner, we checked the manufacturer’s instructions and saw that we had done everything right, so we mixed a second smaller batch to see if we got the same results. Unfortunately, we did, and we put off painting until we got an answer to the problem. It turned out that the coating was warm, the thinner was cold, and we created a mess. A few days later, we obtained an entirely different product and set about again to coat the aircraft. We decided to paint with an airless system. The belly of the aircraft came out beautifully, but when we reached the topside, all hell broke loose. The coating would go on beautifully then within about 30 seconds start to pinhole and fish eye. Knowing the amount of surface preparation we had put into this aircraft, we were amazed at the sudden turn of events. We had no choice but to stop, let the coating dry, and resand the areas we had sprayed. The next day we applied a primer/sealer with good results and got ready once again to apply the topcoat. So there we were with new coating, good equipment, and ready to go. We mixed the coating, pressurized the pot, and started to spray. We got about 5 minutes of good spraying when we started having trouble with the paint. It was thick and would not atomize properly so we again stopped to see what was going on. We opened the pressure pot to find that the paint had already set up and was almost Metal Finishing
100% cured! Did you know that there is no way you can get cured paint out of 75 feet of fluid line? It also does a real number on paint guns and pressure pots! By this time, we were pretty fed up with the whole process and called the manufacturer. The unused coating was returned for analysis and we later learned that during the manufacturing process, a decimal point had been moved and instead of 1% of a curing agent, there was 100%. Hey, worked great but nb pot life! We were then almost 3 weeks into a project that should have taken no more than 10 days and decided to walk away from it for a few months. Thinking that time away and a fresh start 3 months later may turn our luck around, we left the aircraft in that condition and made plans for a fall return. It was now mid-September, the summer heat was gone, and we were ready to tackle the project. Our crew met up; we again sanded off the bad coating, and were right on schedule. Three days into it, we were ready to paint once again. Beautiful weather conditions, equipment that had been checked out, and coating that had been pretested for usability. What could go wrong? Murphy, that’s what! Obviously, he liked his living conditions in the hangar and decided to stay. We did a prepaint wipe-down and thought everything was fine. We started to spray and had immediate failures with pinhole/cratering. By now, we were all ready to pull out hair. We went through the list of what could have gone wrong, like contaminated thinner used during wipedown, dirty cloths, oil in the airline, contamination of the equipment, or coating or environmental contamination. We changed out equipment, swapped out our air source, got new thinner and cloths, and tried to eliminate any potential contamination sources. Everything checked out, so we were now again facing a real problem. The deadline for the unveiling of this plane was only 12 days away and we were no closer to a finished product than we were in June. This is when we started grasping at straws. There was a coating manufacturer in town that we were familiar with and turned to them for help. They have a lab on site so we stripped some coating from the aircraft to look at under a microscope. It turns out that the protective coating that was used over 10 years ago at the boneyard had soaked into the paint system and while we thought we were sanding it off, we were actually driving it deeper into the coating surface. Short of stripping the aircraft to bare metal, we were in a no-win situation. The local manufacturer had an epoxy-based March 2002
Figure 1. T-38 jet aircraft, used by the Air Force for pilot training, in the final stages of refurbishment.
ceramic coating that is one of the most forgiving paints I have ever seen and we were given some to try as a “barrier” coat. By now, we are all “gun shy” but decide to give this a chance. The coating went on and did not pin hole, so we shot the plane with it and let it dry. We actually had a paintable surface to work with 24 hours later. Two days
Figure 2. The tail cap was completely markings were applied.
rebuilt and is shown after
15
BIOGRAPHY Kate Kubernach is President of KMR Consulting Inc. She has been painting aircraft for 30 years. KMR Consulting Inc., located in Seaford, Va., and Las Vegas, provides training in paint applications with heavy involvement in the military and aviation industry. MF
later, the plane was white and glossy and we put the markings on. (See Figs. 1 and 2.) With 6 days to spare, we closed up shop and turned the plane back to its rightful owners. We know that Murphy has now moved on, but since he left no forwarding address, it is anybody’s guess as to where he may turn up next.
Nickel and Chromium Plating, Third Edition by /. K. Dennis and 7X Such
449 pages $155 .OO
In this book the authors describe the industrial processes for carrying out nickel and chromium plating. New material reflects the move from purely decorative and corrosion protection of mass produced articles to surface engineering of more valuable products. Updated throughout, new material of particular interest appears on environmental and health concerns, electroless nickel, electroforming, and alloy deposition. Send Orders to: 650 Avenue of the Americas, New York, NY 10011 For faster service, call (212) 633-3199 or FAX your order to (212) 633-3140
METAL FINISHING:
All book orders must be prepaid. Please include $5.00 shipping and handling for delivery of each book via UPS in the U.S., $10.00 for each book shipped express to Canada;and $20.00 for each book shipped express to all other countries.
With’
l
A
CIear
Solution
l Closed Loop Recycle Process Specific Engineering l Turnkey Systems
dromatix.com Circle 066 on readercard 16
l
or go to www.thru.to/webconnect Metal Finishing