ARTISANS TRAINED IN DVD PROCESS

By Bill Bartkus
NAVAIR Depot North Island

NAS NORTH ISLAND – Call it a win-win situation made possible by teammates working in the NAVAIR Deport North Island Materials Laboratory and artisans in Building 250. Engineers and technicians from the Materials Lab used their technology and expertise to devise a solution to repair surfaces on F/A-18 E and F models. They trained and certified Dept artisans in the Double Vacuum Debulking (DVD) process.

“There is more advanced composites usage on the E and F models than there is on the A through D models, and we had to devise a better method of making repair patches,” said Douglas Perl, a materials and processes engineer in the Materials Lab).

Doug said that the Depot uses pre-cured patches to repair relatively flat surfaces on the Hornets’ A through D models, which he referred to as legacy Hornets, and wet layup for complex contoured surfaces.

“We take dry, woven carbon cloth and impregnate it with a two-part resin and make the patch based on the strength and stiffness that is required for the repair. But there is a problem with this technique,” said Doug. “Because it is manually impregnated with the resin there is a lot of porosity – air bubbles trapped in the resin after it cures causing a significant reduction in strength compared to one which didn’t have any porosity in it.”

Doug also added that this system was fine to use on the legacy Hornets because there aren’t that many areas where the Depot needs to use the wet layup process. “But there are so many different types of composite construction used on the E and F models that a different process was needed,” he said. “The Depot now uses the Double Vacuum Debulking (DVD) process.”

This procedure uses the same carbon woven cloth but a different resin and a different method of impregnating the resin and making the laminate. “This process gives almost a porosity-free panel which is a lot stronger,” Doug said.

The Depot Industrial Business Operations Department (6.1) needed trained artisans to repair E and F Hornets, but “at the time, the Materials Lab was in the process of developing and reestablishing repair training for the fleet and didn’t have time to develop training for the E and F aircraft,” he said.

Doug, who was inducted as a NAVAIR Technical Associate Fellow in March 2001, worked with engineers from F/A-18 structures to define the technical requirements and the Business Office contacted the Boeing Co. in St. Louis (Mo.) and asked the aircraft company to provide the training.

Four Depot artisans – three from North Island and one currently on temporary duty at Lemoore – traveled to St. Louis for training but there was a hitch. “Boeing couldn’t make the process work right,” said Doug, “and the company couldn’t complete the training.

Working together with engineers at NAVAIR Headquarters in Patuxent River, Md., Depot engineers incorporated the DVD process locally in the Materials Lab and trained the artisans. Zachary Himan, Building 250 supervisor, hand-picked John Ruiz, Linda Galley, Danny Abbott and Mark Heacock to be trained in the DVD process.

Doug said that the artisans are the first in the Navy to be certified in the DVD process.
“This is good news on the E and F tech front,” said Industrial Business Operations Department Head Walt Palmer. “This capability is essential to E and F composite repairs.”

Kenneth Ramos, F/A-18E/F Depot Capability Team Lead echoed Walt’s views. “This is great news,” he wrote in an email to Doug. “Thanks to your department in helping achieve this milestone.” Ken congratulated the artisans on a great job saying, “Your successful completion of this event helps the Depot to become a big time player in their field of repair.”
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