Acrylic Elastomer Coating
HJ-243 is a advanced acrylic elastomer coating
that combines high solids emulsion polymers, reinforcing
laminar pigments, and potent biocides to
provide superior durability, reflectivity, weatherproofing,
and mildew resistance. Non-migrating fire
retardant chemicals are permanently locked into the
cured coating to assure long-term performance.
HJ-243 is unique among acrylic elastomers in
that elongation and tensile strength properties are
both maintained at lower temperatures.
HJ-243 was specifically developed for protecting
sprayed polyurethane foam insulation from degradation
caused by normal weathering, aging and ultraviolet
exposure. HJ-243 has the unique property of being
an elastomeric coating that is able to uniformly cover
the profile of textured substrates. It has excellent adhesion
to polyurethane foam, concrete, masonry, primed
metal, primed wood and asphalt. HJ-243 is used
for protection of sprayed polyurethane foam on new
roofs, existing roofs, and hot or ambient storage tanks.
HJ-243 is available in standard White, Tan,
Light Tan and Solar Gray colors
HJ-243 color concentrate is available to create a
Dark Gray HJ-243, if required, to achieve a faster
dry time at lower temperatures. If a faster drying white
topcoat is desired, HJ-243 is available in a Quick-
Set version . The Quick Set formulation
sets up, or congeals, faster than standard HJ-243
so that it will achieve resistance to wash-off from a
light rain or dew in a shorter period of time.
1. Solids by Weight:
66% (±2) [ASTM D1644]
2. Solids by Volume:
55% (±3) [ASTM D2697]
3. Dry Time for Foot Traffic Resistance:*
3 hours at 75°F (24°C), 50% R.H.
Medium Gray @ 16 wet mils (406 microns)
5 hours at 75°F (24°C), 50% R.H.
White @ 16 wet mils (406 microns)
*Dry times will increase with lower temperature and/or higher
4. Ultimate Tensile Strength:
224 psi (±) @ 75°F (24°C)
5. Elongation at Break:*
226% (±) @ 75°F (24°C)
* HJ-243 is unique in that it maintains its elongation values
at freezing temperatures, as well as after extended weathering.
55-65 Shore A [ASTM D2240]
5.7 U.S. Perms @ mils (508 microns)
0.11 Perm Inches [ASTM E96]
9. Temperature Limits for
Normal Service Conditions:
-30°F to 0°F (-35°C to 93°C)
Standard Warranty to the Building
Owner is available for 5-year, 10-year or 15-year
periods at no cost. Refer to Application
Instructions for minimum thickness requirements
to qualify for warranty programs.
Application Instructions for details.
1. ASTM D6083 Conformance:
This specification was developed to establish a
threshold level of quality for acrylic roof coatings.
It includes detailed procedures for conducting
13 separate test methods in order to
ensure consistency of the values obtained.
HJ-243 has been independently tested and
certified to exceed ASTM D6083 standards.
2. Resistance to Accelerated Weathering:
HJ-243 test panels were placed in the
Xenon Test Chamber. Cycling was set at 9
minutes of water spray with ultraviolet radiation,
and 51 minutes of ultraviolet radiation only.
Temperature within the test chamber during UV
cycle was maintained at 145°F (63°C). After
3,000 hours of continuous exposure, HJ-243
showed no deleterious effects, no surface checking
or cracking, no delamination and no color
fade. ASTM D6083, ASTM D4798
5. Film Breathing Ability:
Permeance was determined using perm cups in
accordance with the Standard Test Method for
Water Vapor Transmission. HJ-243 at
dry mils (508 microns) has a perm rating of 5.7
U.S. Perms (3.76 metric perms). ASTM D1653
6. Ponded Water Adhesion:
A 5" (12.7 cm) high column of water was
established over polyurethane foam coated
with HJ-243. After 30 days of continuous
testing, HJ-243 showed no significant loss
of adhesion. No blistering or other deleterious
effects were observed. There was no migration
of water into the polyurethane foam substrate.
7. High Temperature Stability:
When tested in a thermostatically controlled
heat chamber, HJ-243 did not age-harden
or slump at temperatures up to 0°F (93°C).
8. Simulated Hail Damage:
HJ-243 coated foam panels passed multiple
impacts from a 1" (4.4 cm) diameter, ¾
lb. (.3 kg) steel ball dropped 17 ft. 9", (4.6 m)
with no evidence of membrane failure. Test
was repeated following 1,000 hours Weather-
Ometer exposure. No changes were noted.
9. Bond Strength:
Testing Instrument – 50 to
60 lbs./sq. inch (.34 to .41 MPa) breaking
strength. There was no adhesive failure
between the HJ-243 coating and the
polyurethane foam substrate. HJ-243
remained totally bonded to the polyurethane
foam under all stress conditions. Separation
occurred within the polyurethane foam itself.
10. Elongation Retained After Aging:
After 1,000 hours exposure in the
Xenon Test Chamber, HJ-243 passed the
requirements of ASTM D6083/ASTM D2370 –
minimum 100% @ 73°F (23°C). Elongation
was measured before and after weathering,
using the Testing Instrument.
11. Resistance to Foot Traffic:
Penetration plate – 29 lbs./sq. inch (0 kPa).
No tearing, cracking, rupturing or permanent
deformation of the HJ-243 coating, or
exposure of the polyurethane foam was
observed. This test exceeds
the stresses of normal roof maintenance traffic.
12. Low Temperature Flexibility:
HJ-243 is capable of withstanding 180°
bends over a 3/16" (5 mm) mandrel @ -21°F
(-30°C). Test Method No. 141a-6221
13. Cold Temperature Flex After Weathering:
After 1,000 hours exposure in the
Xenon Test Chamber, HJ-243 retained its
ability to withstand multiple " (1.2 cm) mandrel
bends without cracking at -15°F (-18°C).
ASTM D6083, ASTM D522
ADVANTAGES OF HJ-243
1. High Acrylic Resin Content:
Percent solids by volume is only one measure
of a coating’s quality. Another basis for determining
longevity of a coating is the ratio of
filler pigment to polymer content. HJ-243
contains lower filler pigment load and higher
levels of acrylic polymer than most coatings.
This high ratio of pure acrylic polymer provides
long-term durability and weather resistance.
HJ-243’S superior performance is
assured through the use of advanced elastomeric
2. No Plasticizers:
There are no migratory plasticizers in
HJ-243. The purpose of a plasticizer is
to give good initial flexibility to the cured
film. Plasticizers, however gradually leach
from the coating when exposed to sunlight
and moisture, causing it to become brittle and
exhibit poor flexibility and elongation properties.
Surface checking and cracking occur,
allowing moisture into the polyurethane foam
and underlying substrate. This does not occur
3. Uniform Film Build:
The thixotropic consistency of HJ-243
gives it excellent vertical hold, allowing
uniform build on the highs and lows of the
polyurethane foam texture. This quality
maximizes the coating’s ability to provide
prolonged weather resistance.
4. Long Term Fire Protection:
Non-migratory fire retardants are dispersed
into the raw material complex during the
manufacturing process. These fire retardants
become an integral and inseparable part of
the HJ-243 coating. The non-leaching
qualities of the specific fire retardants chosen
by HONEST JOY add another dimension to
HJ-243’S impressive list of protective
5. Abrasive Weather Conditions:
HJ-243 will take normal abrasive weather
conditions of all types. Ice, snow and sand will
not penetrate its tough, dense surface under
6. Non - Polluting:
HJ-243 contains no solvents. It conforms
to all federal, state and local air pollution
standards and VOC requirements.
7. Volume Solids:
The high volume solids of HJ-243, along
with its excellent hide and vertical hold characteristics,
allows for higher film build in fewer
coats. This enables HJ-243 to uniformly
cover the uneven surface texture of polyurethane
8. Single Package:
No catalyzation – HJ-243 is a ready-touse
material. It has no pot life limitations.
LIMITATIONS & PRECAUTIONS
Do not apply HJ-243 at temperatures below
50°F (10°C), or when there is possibility of temperatures
falling below 32°F (0°C) within a 4-hour
period after application.
HJ-243 requires complete evaporation of
water to cure. Cool temperatures and high humidity
retard cure. Do not apply if weather conditions
will not permit complete cure before rain, dew or
freezing temperatures occur. Do not apply in the
late afternoon if heavy condensation may appear
during the night.
HJ-243 will freeze and become unusable at
temperatures below 32°F (0°C). Do not ship or
store unless protection from freezing is available.
HJ-243 should generally not be used over cold
storage tanks or buildings unless applied over a
vapor barrier coating. HJ-243 shall not be used
for interior applications in place of a thermal barrier.
FIRE RATINGS & APPROVALS
UL-790 Class “A” Systems*: HJ-243 has
UL-790 Class “A” classification
over many different types
of UL classified spray-applied
polyurethane foams. Refer to
UL Roofing Materials and
Systems Directory or UL website
for foam manufacturers
and types, foam thicknesses
and densities, inclines and coating requirements of
rated roof systems.
HJ-243 is approved as a fire-retardant roof
coating over many different types of spray-applied
poly urethane foam on non-combustible substrates,
existing fire-retardant BUR & new wood substrates.
BUILDING CODE & INSURANCE ACCEPTANCE
Building Code Acceptance:
HJ-243/Polyurethane Foam Roofing Systems
are accepted by all major model building code
authorities for Class “A” and Class “B” constructions.
These building code authorities also accept
UL Construction No. 136 as an approved roof system
over metal decks without a thermal ignition
HJ-243/Polyurethane Foam Roofing Systems
are readily accepted by major commercial and
industrial insurance underwriters.