REPORT ON THE DEGRADATION OF WOOD FLIGHTS
PROBLEM: Wood when continuously submerged in water is not subject to causing decay.  It has long been established that aerobic bacteria, the principal agent that produces decay in wood, cannot attack wood submerged in water. Witness the old hulks of wrecked wooden ships found in reasonably good condition after being submerged for over one hundred.  Still the irrefutable evidence of decay in wood flights remained.
The cause of this decay in wood flights is the result of electrolytic corrosion and is best explained in A.J. Baker’s report on DEGRADATION OF WOOD BY PRODUCTS OF METAL CORROSION: U.S.D.A. Forest Products Laboratory, Madison Wisconsin.

Basically, soluble chlorides present can form acidic conditions around metal connectors in wet wood. This acidic condition accelerates corrosion of ferrous metal connectors and causes the cellulose of the wood to hydrolyze and weaken the wood. This "crevice corrosion" usually requires an incubation period to develop, but once started it proceeds at an ever increasing rate.		 TYPICAL DECAY AS A RESULT OF HYDROLYSIS PRODUCED BY ELECTROLYTIC CORROSION


SOLUTION: Extended longevity of wood flights can be achieved by: Selecting a species of laminated wood with a minimum of "Tannin" content, insulate the metal connectors and use stainless steel connectors or metals coated with a protective coating to prevent oxidation.

Reduced acidity is accomplished specially designed Flight Grade Laminated Douglas Fir. Additionally, Engineered Lamani can actually enhance the performance of Laminated Flights versus Redwood or other Redwood or other materials.

Insulating the attachment links is accomplished by inserting a mat of Preform Sealant Tape between the metal connectors and wood flight. The unique characteristics of  Preform Sealant Tape to expand and fill voids between the wood flight and the connectors eliminates stress risers. Preform Sealant Tape is a superior insulating device and expansion joint material used in adverse conditions found in waste treatment facilities.

Bolts, nuts and washers used to attached flights to the connectectors should be either 304 stainless Steel or should be coated with a protective coating such as an epoxy bonded fluoropolymer. Such coatings are used in off shore oil drilling platforms and fertilizer storage buildings.