Product #633 – High-Build Chemical Resistant Novolac Epoxy
Installation Guide
Recommended System:
Primer: Product #12 Epoxy Primer (primary choice)
Alternate Primer (when specified): Product #899 Epoxy Primer
Topcoats: Two coats of Product #633 Novolac Epoxy
System Thickness: approximately 21–27 mils (combined)
1. General Information
Product #633 is a 100% solids, high-build Novolac epoxy coating designed for harsh chemical and solvent exposure. It is typically used in secondary containment, pump pads, trenches, process areas, and other locations where standard epoxy may not provide adequate protection.
The recommended system is Product #12 Epoxy Primer followed by two coats of Product #633 Novolac Epoxy.
Primer Selection – Product #12 vs Product #899
Both Product #12 and Product #899 are fully acceptable and compatible primers for use under Product #633. They provide similar adhesion, and either can be used in most installations with excellent results.
Product #12 is recommended for most Product #633 applications because it offers slightly better chemical resistance than Product #899. If a scratch or gouge penetrates the #633 topcoat but does not cut through the primer, the floor can still retain chemical protection. This gives the system an important field advantage in aggressive environments.
Using Product #12 also helps future-proof the installation. If a facility later transitions to harsher chemicals, the system is already built with higher chemical resilience.
Product #899 is completely acceptable as well. Its main practical advantage is in slightly damp concrete conditions where achieving a fully bone-dry surface is not realistic. In borderline moisture conditions, Product #899 may wet the concrete a little better and help reduce installation risk.
Outside of this moisture edge-case, both primers perform well — but Product #12 provides better chemical resilience and future-proofing for industrial and containment environments.
2. Surface Preparation
Proper surface preparation is the most important part of any epoxy installation. All substrates must be prepared to a minimum profile of ICRI CSP-2 or better. For detailed procedures, see our Epoxy Surface Preparation Guide.
Before installation, check the following:
- Concrete placement: Slabs on grade should have a functioning vapor barrier. If moisture migration is present, a moisture mitigation system may be required.
- Finishing techniques: Hard-troweled or dense surfaces must be mechanically profiled.
- Age of concrete: Concrete must be cured, clean, and structurally sound.
- Previous contamination: Oil, grease, solvents, and chemical residues must be completely removed.
- Present condition: Remove weak, punky, dusty, or scaling concrete. Repair cracks, spalls, and delamination before coating.
Environmental conditions:
Ideal substrate temperature: approximately 75°F
Minimum slab temperature: 60°F
Avoid high humidity and conditions that may cause amine blush.
3. Material Quantities (Per 1,000 ft²)
| Component | Coverage | Approximate Quantity |
|---|---|---|
| Product #12 Primer (or Product #899 if specified) | 200–275 ft² per gallon | 4–5 gallons |
| Product #633 Novolac Epoxy Coating | 160–200 ft² per gallon per coat | 10–12.5 gallons (total for two coats) |
4. Installation
A. Primer – Product #12 (Recommended)
1. Mixing
- Stir each component individually before mixing.
- Mix two (2) parts by volume of Part A with one (1) part by volume of Part B for approximately three minutes using a low-speed drill and mixing paddle.
- If thinning is desired, add no more than one pint of xylene or MEK per gallon at the time of mixing.
- Only mix the amount of material that can be applied in 15–20 minutes (less in hot weather).
- Do not leave mixed material sitting in the pail for more than about three minutes; working time will be significantly reduced.
2. Application
- Pour the mixed primer in a ribbon onto the prepared concrete.
- Spread with a flat trowel, notched squeegee, or roller to a coverage of approximately 200–275 ft² per gallon.
- For smaller batches, the dip-and-roll method is acceptable and often easier.
- Back-roll with a short-nap roller to even out the primer.
- Allow the primer to cure 8–12 hours at 75°F before topcoating.
- If the primer is allowed to sit more than 24 hours, lightly sand and clean before applying Product #633.
B. Product #633 Novolac Epoxy Topcoat
1. Mixing
- Stir each component prior to mixing.
- Mix two (2) parts by volume of Part A (base) with one (1) part by volume of Part B (hardener) for approximately three minutes using a low-speed drill and mixing paddle.
- If slip resistance is desired, add Epoxy.com Anti-Skid Fine at 8–12 fluid ounces per gallon of mixed epoxy and mix for an additional minute until well dispersed.
- Mix only the amount of material that can be immediately poured out and applied.
2. Application
- Immediately pour the mixed material onto the floor in ribbons or strips.
- Spread at a rate of approximately 160–200 ft² per gallon using a squeegee.
- For smaller batches, dip-and-roll can also be used if batch sizes are kept manageable.
- Back-roll immediately with a short to medium nap roller. Do not over-back-roll; this can pull the coating too thin.
- Maintain a wet edge as you work to avoid lap lines and cold joints.
3. Cure Schedule
- Allow to cure overnight, or a minimum of 12–16 hours at 75°F, before applying the second coat.
- Apply the second coat using the same procedure as the first.
- Allow the system to cure approximately 24 hours before light traffic and 48 hours before heavy traffic.
- For hot tire traffic and full chemical exposure, allow 5–7 days for full chemical cure.
More Information
To read more about these and other epoxy systems, visit Epoxy.com.
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