For Contractors

Field notes, tools and support for the contractors who apply Tnemec coatings. The Wet Edge lessons below cover the steps that decide whether a job passes inspection and holds up: film thickness, dew point, profile, pot life, recoat windows, concrete moisture and holiday testing. Each one ends with a bottom line your crew can use on the next job.

Question on a job? Call 484-644-5303 or email atlantic@tnemec.com.

Coating Takeoff Calculator

Measure the surfaces, pick the Tnemec system and get gallons per coat with a loss allowance. Coverage figures come from each product's published data sheet, so the takeoff starts from the same numbers the spec does. Use the Open the Takeoff Calculator button on this page.

The Wet Edge Field Notes

Short lessons for foremen, applicators and estimators. Each one covers one topic, one practical move and one bottom line, with the standard or data sheet behind it. Start with the list below; new lessons are added as they are published.

Product Recommendations

Not sure which Tnemec system fits the substrate, the exposure or the schedule? We help contractors choose products, read the data sheets and sort out substitution questions before the bid, so the system you price is the system the spec calls for.

Field Support and Crew Training

We attend pre-job meetings, visit the site during application and train crews on surface prep, mixing, application and inspection. When something looks wrong on the job, call us before you coat over it. As an independent Tnemec representative, we can also connect you with technical resources at the manufacturer.

Contractor blasting a bolted steel tank before coating

Open the Takeoff Calculator

The Wet Edge: Field Notes for Coating Crews

Fluted water tower pedestal on a cold, clear day

Can I Just Thin It More When It's Cold?

Why adding extra thinner to cold epoxy causes problems, and how to warm material and stay inside data sheet limits.

Coated steel girders and bolted connections on an elevated structure

The Inspector Isn't Holding You Up

Why a signed hold point protects the contractor, and how to plan inspections and keep your own daily readings.

Concrete basin being coated at a wastewater plant

Find the Holidays Before the Water Does

Low-voltage wet sponge and high-voltage spark testing for tank and clarifier linings, when to test, and how to repair.

Tall standpipe water tank during recoating

Data Sheet Coverage Is the Window-Sticker MPG

How to calculate theoretical coverage from volume solids and DFT, and why estimators need a loss factor from their own jobs.

Coated concrete floor in a large warehouse

Dry on Top Doesn't Mean Dry

Plastic sheet, calcium chloride and RH probe tests compared, typical moisture limits, and when to test a slab before coating.

Coated bolt heads and seams on a bolted steel tank

Edges Lose the Paint First

Why coatings pull thin at edges and welds, and how a brushed stripe coat protects the places steel fails first.

Steel tank mid-recoat with spot-primed panels and a boom lift

The Max Recoat Window Is Real Too

Missing an epoxy's maximum recoat window can cause intercoat adhesion failure. What to do when the schedule slips.

Epoxy coated concrete wall inside a treatment basin

Wash the Blush Before You Sand It

What amine blush is, what causes it, and why it must be washed with warm water and detergent before sanding or recoating epoxy.

The Pot Life on the Data Sheet Isn't Your Pot Life

Why epoxy pot life shrinks with heat and batch size, with Tnemec Series N69 figures, and how crews should mix and mark kits.

More Profile Isn't More Grip

Excess blast profile leaves rogue peaks that cause pinpoint rust and wastes coating. How to stay inside the spec range.

Coated steel water storage tank on a sunny morning

Five Degrees Is the Floor, Not the Target

Why 5°F above the dew point is the minimum, not a safe margin, and how crews should read steel temperature through the day.

Fresh wet coating film on a steel surface

Check It While It's Wet

How a wet film gauge lets your crew fix film thickness on the current coat, and the WFT math for thinned coatings.

Field Quick Reference

Wet film target. WFT = DFT ÷ volume solids. If you thin, multiply by 1 plus the thinner percentage. A 5-mil DFT spec with a 67%-solids epoxy needs about 7.5 mils wet, or about 8.2 thinned 10%. (ASTM D4414)

Theoretical coverage. 1,604 × volume solids ÷ DFT = square feet per gallon before losses. Tnemec Series 66 at 56% solids and 4 mils DFT works out to about 225 sq ft per gallon. Apply a loss factor from your own jobs.

Dew point. Keep the steel at least 5°F above the dew point through prep, application and cure. Read the coldest steel, not the air. If the data sheet asks for more, the data sheet wins. (ASTM D3276)

Concrete moisture. Common limits are 3 lbs per 1,000 sq ft in 24 hours (ASTM F1869) or 75 to 80% RH (ASTM F2170). Give new concrete its 28-day cure. The product data sheet sets the limit.

Holiday testing. Under 20 mils, low-voltage wet sponge at 67.5 or 90 volts. Thicker linings, high-voltage spark set by film thickness. Test after cure and before service. (NACE SP0188)

Recoat windows. Check the minimum and the maximum. Past the maximum, abrade per the data sheet before the next coat.

These are field rules of thumb. The current product data sheet and the project specification always govern.

Questions on a Job?

Tell us what you are coating and what the spec calls for, and a consultant will follow up. Call 484-644-5303, email atlantic@tnemec.com, or use the contact form.