Projects/Information Exchange Non-Hexavalent Chromium No Hazardous Air Pollutents Aircraft Sealant Skyflex Aircraft Sealant is an effective environmental sealant alternative to chromate-containing polysulfides for all aircraft platforms. Skyflex contains no HazMats, is simple to apply, reduces maintenance man-hours, and improves aircraft availability/mission readiness. Skyflex sealants suffer none of the negative environmental affects of current aircraft sealants, which use a polysulfide mix containing hexavalent chromium and volatile solvents such as MEK and toluene. Usage and emissions/discharges of materials containing hexavalent chromium, MEK and toluene are heavily regulated. Because of its toxicity, sealants containing hexavalent chromium, waste from unused mixed sealant, removed cured sealant, and any containers, rags or other contaminated equipment must be disposed of as a hazardous waste. Polysulfide sealants also have several application/installation drawbacks. Polysulfide sealants are two-component sealants that require mixing and subsequent cure. For an average panel, the mixing, masking, mold releasing, sealing and clean-up steps can take 2 hours to 2.5 hours to seal. The sealant then requires at least 16 hours to cure before the aircraft may be flown. If the humidity and/or temperature are low, the sealant may require cure times in excess of 72 hours. Many panels are frequently opened on a set schedule (every 14, 28, 56 days) and the sealant must often be replaced, which results in down time. This can have a severe adverse effect on maintenance man-hours and aircraft down time for maintenance. Skyflex is an adhesive-backed expanded PTFE sealing tape that requires no mixing or subsequent cure. Skyflex has demonstrated effectiveness on non-pressurized, non-fuel panels of the S-3/ES-3, P-3, H-60, E-6, EA-6B, H-1; on pressurized panels of the S-3/ES-3; on floorboards of the H-53, P-3, H-60, and C-130; and on windshields of the C-130. Superior corrosion resistance is achieved because it creates a better environmental seal than current sealants. Because PTFE (Teflon®) is hydrophobic, even a contact seal repels water from the fay surface. Another principle advantage of Skyflex over current sealants is that it is reusable over multiple panel removals. Although there is very little recovery from compression by the PTFE foam (~8%), from the 4 years of experience on the S-3, the recovery is enough to reseal the panel after it has been removed and replaced multiple times. Skyflex sealant contains no hazardous components. As such, this product will eliminate the generating, handling/exposure and disposal of wastes associated with polysulfide sealing operations. As a result, Skyflex exhibits a two-fold compliance benefit: elimination of wastes that must be classified and therefore disposed as hazardous, and possible reduction of overall requirements that must be meet under RCRA, 40 CFR 260-268 and SARA Title III (Sec 313). Other benefits include: Improves aircraft availability and mission readiness by reducing downtime due to maintenance and replacement of panel seals. Reduces cost in terms of man-hours and material (sealant can be reused multiple times without replacing) and disposal of hazardous waste. Eliminates the hazardous aspects (handling, exposure, packaging, waste disposal and federal regulations) normally associated with polysulfide sealants. Superior corrosion resistance is achieved because Skyflex creates a better environmental seal than current sealants.	Related Topics Project Matrix and Points of Contact Meeting and Teleconference Summaries Project Summary
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