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Quantum 99 Topcoat How To

Genius Painter

Quantum99 Topcoat: Preparation, Mixing, and Application

Quantum99 is a two-part acrylic-polyester hybrid polyurethane topcoat engineered for heavy duty and decorative marine environments. This high solids topcoat provides superior protection and beauty to all watercraft, aircraft, and other specialty equipment requiring excellent repairability, exceptional chemical and weather resistance, superior durability and stain resistance, and unrivaled gloss and distinctness of image (DOI).

Quantum99 is the featured topcoat for the Quantum high solids repairable marine finish system (refer to the Quantum System Product Selection Guide for details). Not for use below the waterline.


  • Quantum99 Topcoat Base
  • Quantum99 Urethane Spray Activator (1:1 mix)
  • Quantum99 Urethane Spray Reducer
  • Quantum99 Urethane Brushing Activator (2:1 mix)
  • Quantum Brushing Reducer
  • Quantum99 Urethane Accelerator (Reduces cure time.)
  • Quantum Cool Weather/Fast Reducer (Helps product perform better in cooler weather conditions.)
  • Quantum Flattening Paste (Changes the finish from high gloss to semi-gloss or flat.)
  • Quantum Anti-Skid Paint Additive (Provides greater footing on deck.)

Surface Preparation

Apply the Quantum45 primers directly to properly abraded wood, fiberglass/gelcoat, carbon fiber, and previously painted surfaces. Refer to the Quantum45 Primer How To sheets for primer application details. Use the two-rag wipe-on/wipe-off method to solvent clean with Quantum Surface Prep Cleaner and lint-free cloth prior to topcoat application so that surfaces are free from dust, oils, corrosion, or any other surface contaminants. Tack rags are not necessary or recommended prior to Quantum99 Topcoat application.


Shake or stir the base component and activator well.

SPRAY APPLICATION: To 1 part Quantum99 Topcoat Base, slowly add 1 part Quantum99 Urethane Spray Activator by volume. Agitate to ensure complete mixing. Though not normally required, a 10% reduction by volume of the admixed paint with Quantum99 Urethane Spray Reducer or Quantum Cool Weather/Fast Reducer may be used for proper application, film thickness control, and a smooth film appearance. Allow mixed material to stand for 5 minutes prior to reduction and application.

BRUSH/ROLL APPLICATION: To 2 parts Quantum99 Topcoat Base, slowly add 1 part Quantum99 Urethane Brushing Activator by volume. Agitate to ensure complete mixing. Allow mixed material to stand for 5 minutes prior to reduction and application. Use Quantum Brushing Reducer to reduce up to 1 part (or 33%) as needed, based on flow. EXAMPLE: 8 oz. Quantum99 Topcoat Base, 4 oz. Quantum99 Urethane Brushing Activator, and 0 to 4 oz. Quantum Brushing Reducer.

To accelerate cure time for spray or brush application, use Quantum99 Urethane Accelerator taking care not to exceed 1 oz. (30 ML)/ mixed gallon. The accelerator will maintain the 75°F cure profile when added at 5 ML/mixed gallon every 5°F below 75°F. At 75°F, 1 oz. (30 ML)/mixed gallon reduces Dry to Tape Time to 4 hours; Dry to Touch time to 1 hour. This product can be used at temperatures up to 100°F, though caution should be taken as pot life will be reduced.


SPRAY APPLICATION: This product can be applied using conventional air spray equipment, HVLP, Graco Pro 4500 air electrostatic, or Graco Pro 4500 air assisted airless electrostatic. Please consult a Quantum representative (1-843-819-2067) for specific equipment settings.

  1. Check to ensure that pots, guns, and lines are purged and cleaned.
  2. Mix thoroughly and filter strain before spray applying.
  3. Spray atomizing pressure: 50-60 psi (3.45-4.15 bar) Pot pressure: 10-12 psi (0.69-0.83 bar) using a 60' fluid hose (3/8" diameter). Delivery rate: 8-10 fluid oz. (236-295 mL) per minute.
  4. Best application results are obtained by applying two to three medium wet coats, allowing a 45- to 90-minute "tack-off" period between coats.
  5. If the dry time between coats exceeds the maximum recoat time (48 hours for spray; 12 hours for brush/roll at 72°F), the surface should be thoroughly abraded with 320 or finer grit sandpaper.
  6. Recommended dry film thickness is 2-3 mils (50-75 microns). Some colors (such as reds and yellows) may require thicker films to achieve complete hiding.
  7. Pot life is 4 hours at 72°F. However, for best results use the product within 2 hours of mixing. A fresh mix is recommended for the final coat.
  8. Coating will dry to touch in 2 hours and dry to tape in 7-9 hours at 72°F. Product is able to be buffed in 48 hours at 72°F. You can accelerate cure time by using Quantum99 Urethane Accelerator.
  9. Full properties are achieved after curing for seven days (168 hours).

BRUSH/ROLL APPLICATION: Use a 1/8" to 3/16" nap solvent-resistant foam roller. In most cases, tipping is not necessary--simply roll apply in uniform coats, using the roller to uniformly "stretch" the paint. Be careful not to overwork the film (at 72°F the wet edge is ~90 seconds). Second and third coats can be applied once subsequent coats are dry through (~4 hours at 72°F), though sanding between coats can provide a smoother final appearance.

During application, remember that Quantum is very repairable--imperfections can be polished in 48 hours at 72°F (cure time can be accelerated with Quantum99 Urethane Accelerator).

NOTE: Application of these product systems requires recommended temperature/humidity conditions and film thickness ranges. The material, hangar, and substrate (application surface) temperature should be no lower than 45°F before, during, and after application. Do not apply paint materials to surfaces less than 5°F above dew point, or to surfaces warmer than 125°F. Substrate temperature should be minimum 45°F to maximum 125°F.


Use with adequate ventilation and proper respiratory protection. See MSDS for complete details of composition and precautions.

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