What Kind of Trenchcoat Could Look This Good

in 100 Years?

CSP coated with TRENCHCOAT protectivefilm is able to withstand sandy clay run-offand gravel bedload without losing its adhe-sion to metal.1

An independent study was conducted bythe Ocean City Research Corporation thatused their most severe abrasion test method-ology. The study showed that CSP coatedwith TRENCHCOAT film possessed superiorabrasion resistance over metallic coatings,asphalt dipped coatings, and polymer-modi-fied asphalt coatings.

TRENCHCOAT protective film bonds tosteel both chemically and physically. Throughthis bonding, it becomes an integral part ofthe galvanized steel pipe, able to outperformasphalt coating materials. TRENCHCOATfilm exhibits greater than 10 times the adhe-sive peel strength when compared to asphalt.

TRENCHCOAT protective film adds virtually no weight to sections of CSP. As aresult, pipe sections protected with this filmcan be handled more easily than heavier concrete or asphalt-coated corrugated pipe.TRENCHCOAT film also resists damage dueto normal handling and installation — muchmore so than asphalt. And, unlike asphalt,TRENCHCOAT film is not affected byextreme cold or heat found during winter and summer installation.

1Even when TRENCHCOAT film is mechanicallydamaged, a study showed that the normal delamination is no more than one-eighth inch.

SUPERIOR BONDING.

EASY INSTALLATION.

SUPERIOR ABRASION RESISTANCE.

*Trademark of The Dow Chemical Company

TRENCHCOAT*

Heavy-Gauge Protective Film Withstands

the Elements for Long-Term Protection

of Storm Drains and Culvert Systems.

TRENCHCOAT*

Heavy-Gauge Protective Film Withstands

the Elements for Long-Term Protection

of Storm Drains and Culvert Systems.

THE STRENGTH OF STEEL. THE CORROSION RESISTANCE OF CONCRETE.

The Dow Chemical Company providesa winning combination. You can havethe strength, cost effectiveness, and thelighter weight of galvanized corrugatedsteel pipe (CSP), while also having theresistance to corrosion and abrasion of concrete. CSP that is manufacturedwith TRENCHCOAT heavy-gauge pro-tective film combines the benefits ofsteel and plastic.

TRENCHCOAT film is a tough, heavy-gauge film with at least a 10-mil thick-ness. It can be laminated to the insideand outside surfaces of CSP by qualifiedlaminators. The laminated steel coil is

corrugated and formed into pipe of vari-ous diameters to meet the needs of yourspecific application.

TRENCHCOAT protective film givesCSP resistance to corrosion and abra-sion that is superior to aluminizing,fiber-bonded asphalt, PVC plastics, andcoal-tar formulations. CSP coated withTRENCHCOAT film is lighter than con-crete and asphalt-coated pipe, making iteasier to transport, handle, and install.In addition, CSP that is protected withTRENCHCOAT film can withstand abuseduring fabrication, handling, installa-tion, and use.

THE PROOF IS IN THE TESTING.

Figure 1 — Micrograph of Pipe Cross-Section

Zinc

3.3 mil (83 µm)clear

7.0 mil (176 µm)pigmented

TR

EN

CH

CO

AT

2.0 mil(50 µm)

For more than 20 years, Dow has conduct-ed extensive performance testing on thisheavy-gauge protective film.

One laboratory study2 used microscopic andinfrared microspectroscopic analysis of CSPsamples coated with TRENCHCOAT protec-tive films that had been in service for up to22 years. The samples were examined forcracking with an optical microscope. In allsamples, the majority of the TRENCHCOATprotective film coating (effluent side) was ingood physical condition. None of the micro-graphs showed evidence of chemical degrada-tion or cracking, although some of the sam-ples did show evidence of physical abrasion tothe exposed surface.

In the study, Don Waters, P.E., vice presi-dent of Corrpro Companies, Inc., states,“Since we have not seen any measurabledegradation, we can only predict a long service life for CSP protected with theTRENCHCOAT polymer film. We cannot find any data to suggest that this pipe coat-ing would not provide at least 100 years ofservice life.”

This micrograph shows a cross-section of TRENCHCOATprotective film taken from the invert of a 22-year-oldinstallation in Michigan’s Upper Peninsula. The two layers of film in the cross-section and the absence of any cracks or deformation show the excellent, long-termperformance of the TRENCHCOAT protective film coating. (Note the presence of the zinc adhering/bondingto the film itself.)

2Study was conducted by PSG CorrosionEngineering, Inc., a subsidiary of Corrpro, the largest corrosion engineering firm in North America.

100

Film Coating (Effluent Side)

10

20Deg

rad

ati

on

(p

erc

en

t)

Depth From Coating Surface: millimeters

30

40

50

60

70

80

90

100

2 3 4 5 6 7 8 9 10

Using the same sample as Figure 1, this chart shows theresults of spectroscopic mapping. The horizontal axis of thegraph shows the depth of the region being analyzed fromthe exposed coating surface. The vertical axis shows thepercent of degradation of the film at each depth into theprotective film. This sample specimen was very representa-tive of the samples analyzed in the study and showed verylittle degradation over its first 22 years of service.

For more information about TRENCHCOATfilm, its physical properties, or the names of manufacturers who use TRENCHCOATfilm on their corrugated steel pipe, contactDow’s Customer Information Group at 1-800-441-4369.

SPECIFY TRENCHCOAT FILM.

Figure 2 — Coating Degradation Versus Depth of 10-mil Film

START YOUR DECADES OF PERFORMANCE...TODAY.

To ensure that the corrugated steel pipeyou specify for your next project is coatedwith TRENCHCOAT protective film, ask for:“Corrugated steel pipe, coated on bothsides with a protective polymer coatingconforming to ASTM A 742 and AASHTOM-246. The polymer coating shall be aminimum 10 mils thick. The polymershall be composed of polyethylene andacrylic acid copolymer — labeledTRENCHCOAT protective film.”

SUPERIOR CORROSION RESISTANCE.

TRENCHCOAT protective film resists virtually all corrosion, such as acids, salts,and alkalines commonly found in today’sstorm drains and culvert systems.

A test culvert in Butte County, California,features multiple types of pipes experiencingthe same conditions. The environment thereis very acidic, with a water pH around 3.3. At this pH, most damage would be expectedfrom the pH and not abrasion or erosion. Forthe study, invert core samples (above) weretaken. In general, all pipe sections showedinternal degradation in the invert only. Thereinforced concrete pipe was corroded enoughto expose coarse aggregate. The galvanizedG210 pipe sections were severely corroded on all surfaces on the immersed invert andwere perforated numerous times at the crests of the corrugations. The aluminumalloy CMP was severely perforated. After seven years of service, the CSP section coated with TRENCHCOAT protective filmwas in excellent condition, showing no signs of delamination, abrasion, or filmdegradation.

Reinforced Concrete SRP/G210— invert

CMP/Aluminum— invert

TRENCHCOATCSP/G210/

Polymer — invert

For additional information, call 1-800-441-4DOW (4369).

NOTICE: No freedom from any patent owned by Seller or others is to be inferred. Because use conditions and applicable laws may differ fromone location to another and may change with time, Customer is responsible for determining whether products and the information in this docu-ment are appropriate for Customer’s use and for ensuring that Customer’s workplace and disposal practices are in compliance with applicablelaws and other governmental enactments. Seller assumes no obligation or liability for the information in this document. NO WARRANTIESARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLYEXCLUDED.

The Dow Chemical CompanyMidland, MI 48674

Printed in U.S.A. *Trademark of The Dow Chemical Company Form No. 500-01641-398 P&MMCKAY154030