Laserfiche WebLink
t0aIING RESOURCES, INC <br />I~C:f.'(Ctf~1• ,f„l.r,.f 1, t:.i 7f ".C '9['!4C ~ ,.., ,~'a. .~t.pnt. ,,..f(: <br />._. " !_':f! <.~~~'{ ~~.ii! 6;li;illl"Itf ,.fl .:?;., •t ..).I.; °u ,. ,~ Jif 1 ,.,~ i ',hi .. .. <br />NIr. David Berg <br />Cite of Elk River Public Utilities <br />1705 Main Street <br />Elk River, ~fN 5.5.330 <br />RE: Jackson Street Tower <br />4!20/09 <br />ivlr Berg: <br />I appreciate you calling me to meet and evaluate the conditions of the coatings on the above mentioned <br />water tank. <br />1~B® bolted 1L~~edo "]Cank _(]E1k 1l8iver° 1~N1 <br />~acflrground: <br />'This bolted tank was onginall}* constructed and coated in 1920 by IV'linneapolis Steel & Machinery <br />Company Microscopic examination showed what appears to be 5 distinct layers with an average <br />film thickness of 34.2 mils. Spectral analysis of the front layer shows what appears to be an alkyd <br />coating- Please refer to the TNEI~LEC lab report. <br />®bservadons: <br />Exterior: <br />The beige finish has faded and shows a moderate to severe amount of chalking. 'I~here is some <br />spot corrosion on the side walls of the tank (photo 1, 2 & 3) and at the interface of where the <br />side walls meet the coned roof. X-scribes were performed resulting to adhesion ratings <br />consistent with L~ and 3.~ adhesion per aSTM D 3359 :Method .~ (Photo 4, 5 & 6) <br />additionally, while cutting into the coatings they appeared brittle and did trot ribbon off the <br />substrate. <br />1 nterior Wet: <br />I did not observe this portion of the tank. <br />conclusion: <br />Based on the age and the excessive film build of the existing coatings, an over-coat of tlis lank <br />would be a very risky application. additionally, results of the X-scribes I performed indicate <br />moderate to poor adhesion. In our Ereeze/thaw climate, the addition of more coatings and <br />curing stresses will greatly increase die likelihood of a coatings failure/delamination. Please read <br />TNEMECs Technical Bulletin "Over-coating aged Paint Systems." Based an the <br />eecorrtmendations of this document I suggest a complete reconditioning of this tan!: <br />The tnterior wet coatings have reached then expected setwice Gfe of "l2-15 years. I suggest where <br />reconditioning the exterior the Ezell removal these coatings and the applicaton of ~: new coating <br />system. Logically speaking, the tank will be out of sen*ice Eor less time and economicallc it .~]l <br />r_ost less to have the pain ring contractor do the entire rank at: once. <br />boating II+;ecommendations: <br />Exterior ~;~tion ,~1 Hydr-oFlon: <br />Tlus is die best available coating system Eor Iong-term aesthetics. Series 700 (gloss) or "i01 (setru-gloss] <br />ldydroFlon is a fluoropolymer finish that has superior resistance to color fade; chalking, U~ radiation; <br />graffiti, and dirt and mildew pickup. This system. has an expected aesr}tetic set-vice life of o~rer 20 years <br />