||Aromatic Urethane, Zinc-Rich
||A two-component, moisture-cured, zinc-rich primer for the interior and exterior of steel potable water tanks. Provides outstanding long-term corrosion resistance when used as a primer in conjunction with other Tnemec potable water tank coatings. It cures quickly and can be topcoated the same day at surface temperatures down to 35°F. Series 91-H2O has no maximum recoat time, making it ideally suited as a primer for both sides of plate steel surfaces in water tank fabrication shops. Application methods include “dry-fall” under certain conditions (see Application). Note: When used in conjunction with cathodic protection, anodes or impressed current systems should not provide current demand more negative than –1.05 volts relative to a copper–copper sulfate reference electrode half-cell.
||Please refer to Tnemec's Systems Guide for Water Storage Tanks for specific systems and additional information.
Interior: Series 20, FC20, 22, FC22, L140, L140F, N140, N140F, V140, V140F, 406.
Exterior: Series 27, 27WB, 66, L69, L69F, N69, N69F, V69, V69F, 73, 115, L140, L140F, N140, N140F, V140, V140F, 161, 1028, 1029, 1074, 1074U, 1075, 1075U. Note: Certain topcoat colors may not provide one-coat hiding depending on method of application. Contact your Tnemec representative. Note: Series 91-H2O must be exterior exposed for three days prior to topcoating with Series 1028 or 1029. Note: Series 91-H2O must be exterior exposed for one day prior to topcoating with Series 27WB.
||63.0 ± 2.0% (mixed)
||2.5 to 3.5 mils (65 to 90 microns)
† 50% relative humidity. Note: Refer to product listings on www.nsf.org for specific potable water return to service information. Curing time will vary with surface temperature, humidity and film thickness. Ventilation: When used as a tank lining or in enclosed areas, provide adequate ventilation during application and cure. Reference ventilation guidelines contained in the latest edition of AWWA D 102.
|Temperature †||To Handle||To Recoat|
|75°F (24°C)||1 hour||4 hours|
|65°F (18°C)||1 1/2 hours||5 hours|
|55°F (11°C)||2 hours||6 hours|
|45°F (7°C)||2 1/2 hours||7 hours|
|35°F (2°C)||3 hours||8 hours|
Note: For faster curing, low humidity and low-temperature applications, add No. 44-710 Urethane Accelerator (see separate product data sheet). Note: For cure times to immersion service, reference the specified Tnemec interior topcoat product data sheet.
|Volatile Organic Compounds
||Unthinned: 2.65 lbs/gallon (318 grams/litre)
Thinned 2.5%: 2.76 lbs/gallon (331 grams/litre)
Thinned 10%: 3.07 lbs/gallon (368 grams/litre)
||Unthinned: 5.05 lbs/gal solids
Thinned 2.5%: 5.33 lbs/gal solids (No. 2 Thinner); 5.06 lbs/gal solids (No. 3 Thinner)
Thinned 10%: 6.19 lbs/gal solids (No. 2 Thinner); 5.09 lbs/gal solids (No. 3 Thinner)
||1,011 mil sq ft/gal (24.8 m²/L at 25 microns). See APPLICATION for coverage rates.
|Number of Components
||Two: Part A and Part B