UsagePrimer for use with Sikalastic®-500 RoofCoat Systems Suitable for use on:
- Intercoat Adhesion & re-coat primer for existing urethane systems
- High Solids
- Fast Re-Coat Time
- Low Odor
- Low Viscosity
2 gal. (7.6 L) kit
- Part A: 1 gal. (3.8 L)
- Part B: 1 gal. (3.8 L)
10 gal. (37.8 L) kit
- Part A: 5 gal. (18.9 L)
- Part B: 5 gal. (18.9 L)
Part A: Black Part B: White
Two component Polyurethane
12 months in unopened container
Keep containers closed and store in a dry, cool place away from direct sunlight, heat, sparks, open flame, and moisture. Keep material stored above 65 °F (18 °C). Open containers should be blanketed with dry nitrogen before resealing.
Part A: 1.22 kg/l Part B: 0.98 kg/l
97.8 % by weight
97.7 % by volume
Volatile organic compound (VOC) content
500 cps. (at 75 °F (24 °C) and 50 % R.H. Part A+B)
Part A : Part B = 1 : 1 (by volume)
Ambient Air Temperature
41 °F (5 °C) min. / 104 °F (40 °C) max.
Relative Air Humidity
80 % R.H. max.
Beware of condensation. The substrate and uncured coating must be ≥ 5 °F (3 °C) above dew point.
41 °F (5 °C) min. / 140 °F (60 °C) max.
60–90 minutes (at 75 °F (24 °C) and 50 % R.H. Part A+B)
Waiting / Recoat Times
Allow primer to cure completely prior to applying membrane resin.
Full cure: 2 - 4 hours at 68°F.
Maximum primer exposure is 12 hours. Primer exposed longer than 12 hours, and primer exposed to water during curing and exhibiting a chalky appearance, must be reprimed. Deteriorated primer must be mechanically removed before primer reapplication.
1 gal/ Average 300 sq. ft. (0.14 L / m²)
Note: Rough, porous, or absorbent surfaces will require additional primer andwill reduce yield.
The volume mixing ratio is 1 part Part-A Black Liquid to 1 part Part-B White Liquid.
Sikalastic®-503 Primer should be applied at the rate of 1 gal. (3.8 L) (mixture of Part-A & Part-B) / 300 ft2 (27.9 m2). Coverage rate will depend on surface roughness and porosity. It can be applied using an airless sprayer, brush, or phenolic resin core roller. Do not allow the material to puddle.