GacoFlex U-66
Liquid Urethane Rubber
U-66
January 2002
Supersedes 07/00

DESCRIPTION:
U-66 Series Liquid Applied Urethane Rubber compounds are weatherable, fire retardant, two component elastomers.
USAGE:
Intended for use on roofs, mechanical room floors, walking and traffic decks where excellent weathering, fire retardance, toughness, fast cure and good solvent resistance are needed. Suitable substrates include concrete, plywood, sprayed in place polyurethane foam and metal.
STANDARD COLORS:
U-6601 Oyster, U-6602 Pewter, U-6616 Shale, U-6618 Adobe.
APPLIED PRODUCT DATA
WEATHERABILITY:
Excellent durability and chalk resistance, light colors are subject to slight yellowing.
CHEMICAL
RESISTANCE:
Good salt, acid and solvent resistance. Fair alkali resistance. Excellent hydrolytic stability to 160F (71C).
TENSILE:
ASTM D-412

Strength: 2600 100 psi (17.93 .69 MPa)
Elongation: 300% 25%
Permanent Set at Break: 25% Maximum

HARDNESS:
ASTM D-2240 90-95 Shore A
TEAR
RESISTANCE:
ASTM D-624 Die C

Lb./In. Min. 400 25 (71.58 4.47 kg / cm)

WATER
ABSORPTION:
ASTM D-471 Max.

7 days R.T. 2.0%

WATER VAPOR
PERMEABILITY:
ASTM E-96 Procedure B. Max.

100% R.H. Difference 7 days at 23C. 0.012 Perm Inches (.3 mm)

TOXICITY:
Contains solvents which require normal precautions in handling materials of this type. Part B contains approximately 3% isocyanate which is toxic if heated in a confined area or inhaled as particulate matter. Consequently, a particulate matter respirator is required for spray application and containers of Part B should not be warmed above 120F (48C).
ADHESION:
Adheres well to wood, sprayed-in-place polyurethane foam, neoprene, Hypalon coatings and GacoFlex primers. See primer recommendations below (or Primer Recommendation Chart), for specific surfaces. The GacoFlex primer-sealer system is recommended to minimize blistering when coating over porous concrete. U-66 series coatings can be re-coated when set to touch or as much as a week between coats may be allowed, as long as the surface is clean and dry. Use neoprene primer over U-66 to assure adhesion of Hypalon topcoats, when used.
PACKAGED PRODUCT DATA
COVERAGE:
Sq. Ft./Gal./Mil 1195 to 1210 (29.3 to 29.7 m / L/ .025 mm) depending upon color
SOLIDS:
Weight:   Method 4041
              Fed. Std. 141
83.0% to 85.0% depending upon color
Volume: 74.5% to 75.5% depending upon color
V.O.C.:
Conforms to V.O.C. regulations. V.O.C. content is 210 grams per liter.
FLASH
POINT:
ASTM D-56 (Tag Closed Cup)
Part A 22F (-6C).
Part B 60F (16C).
STORAGE
STABILITY:
Part A and B, 1 year at 50 to 80F (10C to 27C).
THINNER:
T-5116 for brush, roller or spray. T-5118 for troweling.
APPLICATION
PRIMER:
Polyurethane Foam No primer necessary
Wood No primer necessary
Concrete Standard GacoFlex sealer system U-5677, E-5320 or E-5481.
Metals other than Copper E-5320 and E-5388
Copper U-5677
MIXING INSTRUCTION:
Examine both components to determine that they have not solidified. Stir Part A to suspend any settled pigment. Combine equal volumes of Part A and Part B. Mix thoroughly (power mixing is mandatory for quantities over two gallons).
POT LIFE:
Pot life varies with the temperature of the material; including the temperature at which the material is stored. As a general guide, pot life can be expected when material temperatures are as follows:

60F (16C) - 2 Hours
78F (26C) - 1 Hour
96F (36C) - Hour

Pot life can be extended twice as long at each temperature with the addition of T-5130 thinner, up to a maximum of 15% by volume.

Brush, roll or notch trowel as mixed. Thin as needed, however, do not thin more than one pint per gallon.

For spray application, thin if necessary with T-5116. Apply with conventional spray gun or with airless spray equipment. When thinning for trowel application at temperatures above 80F (27C), use T-5118 trowel thinner to prevent rapid skin formation on the surface. Up to 15% thinning is allowable to compensate for increasing viscosity which will occur at the end of pot life. Thoroughly clean spray equipment with T-5130 thinner. Circulate through lines and gun until residual U-66 is removed. Flush with clean thinner.

See General Instructions GW-3-1 for safety and storage notes, and GW-3-3 for complete application details.

When application is to surfaces with a temperature between 30F and 50F (-1C and 10C), mix Part A and Part B which have been warmed to 60F (16C) minimum and let mixture stand for 15 minutes before application. This will cause a viscosity increase so that up to one pint of thinner will be required for application. Do not apply U-66 materials to surfaces below 30F (-1C).

CURE:
Applied coating will set in eight hours at 70F (21C) and can be used for light foot traffic after 24 hours cure. For vehicle traffic, an additional 24 hours is necessary.

A special accelerator, U-5651, is available to increase the rate of cure. Up to ounce per gallon (7 ml per 3.78 L) in Part A may be used to double cure rate; pot life will be reduced accordingly. Do not use more than ounce per gallon (7 ml per 3.78 L) in Part A, because using more than the optimum quantity interferes with curing.