SURFACE PREP

The principles for surface preparation for Surecrete DK 500 are aligned with other coatings systems placed on concrete and remain constant; the substrate must be:

1. Clean: The surface must be free of dust, dirt, oil, grease, paints, glues, sealers, curing agents, efflorescence, chemical contaminants, rust, algae, mildew and other foreign matter that may serve as a bond breaker or prevent proper adhesion. To remove coatings, paint, sealers, glue from concrete, etc. best results are achieved through diamond grinding or shot blasting.
2. Cured: Any concrete must be sufficiently cured to have complete hydration, approximately 28 days depending on temperatures & humidity. Cement based overlays typically cure sufficiently within 2 – 3 days.
3. Sound: No system should be placed on flaking or spalling concrete. If the surface is delaminating, or divots are present, then diamond grinding, shot blasting, or other mechanical means should be used to remove the delaminating areas. Depending upon size of area, patching may be required prior to application of Surecrete DK 500. Flash Patch or Deep Level is an excellent choice as a patching product to complement the system. Refer to their respective TDS. Also, cracks may require treatment: evaluate crack as static or structural to set expectation of treatment. Refer to TDS on SCT-22 Crack and Spall Treatment. Construction Joints in concrete may have sufficient movement to “telegraph” through the Surecrete DK 500. Large expansive slabs should have planned appropriate flexible caulks to allow for this movement and prevent bridging of Surecrete DK 500 across either side of the construction joint.
   
   
4. Profiled
   • Concrete: For a proper bond, the surface of concrete must be opened up or roughed up to feel like 80 – 180 grit sandpaper. This profile is best accomplished through diamond grinding or shot blasting. Proper profile should follow the standard established by the International Concrete Repair Institute (ICRI) Technical Guideline no. 03732 for Concrete Surface Profile (CSP). The established profile is categorized as CSP-1 through CSP-3. Customarily cement-based overlays do not require profiling.
   • Finish or Top Coat: Screen the preceding coat with a 100 grit sanding screen on a rotational floor machine. This screening will ensure not only a good bond between coats, but also eliminate any debris or dust that may have settled onto the preceding coat as it was curing. Follow screening with vacuuming. Follow vacuuming with a micro-fiber wipe with a solvent such as dentured alcohol or acetone.
     
     
5. Limit Moisture:Since Surecrete DK 500is not vapor permeable and due to the uncertainty of vapor barriers placed beneath concrete, testing prior to application is appropriate.
   • Plastic sheet test (ASTM-D-4263) can often identify excessive moisture vapor transmission. Tape all 4 sides of an 18” (45 cm) square of clear plastic to the slab and leave in place for 16 hours. Any condensation formed or darkening of the slab beneath the plastic indicates the surface is too wet for polyurethane.
   • Calcium Chloride test (ASTM-F-1869) will quantify the amount of moisture that is transmitted to surface of the slab. The moisture measurement is expressed in terms of pounds (kg) per 1,000 ft² (m²) per 24 hours. Measurements that are in excess of 3 pounds per 1,000 ft² (1.4 kg per 100 m²) over 24 hours are too wet for Surecrete DK 500. Follow directions of test kit manufacturer.

Note: these observations and measurements may be inherently flawed as they are “snapshots in time”. These tests serve only as guidelines.

TEMPERATURE/CURE

Avoid application on extremely cold or hot days or during wet, foggy weather. Basic rules include:

• Apply with ambient and surface temperatures ranging above 50°F (10°C) and below 90°F (32°C) and that will remain within ranges for at least 12 hours following application.
• Surface temperature must be a minimum 5°F (3°C) above dew point.
• Relative humidity should be below 75%.

Cure Rates @ 77°F (25°C)                                      Cure Rates @ 50°F (10°C)

Dry to touch = 6 - 8 hrs.                                           Dry to touch = 18+ hrs.

Light traffic = 16 hrs.                                                Light traffic = 30 hrs.

Heavy Traffic = 24 hrs.                                              Heavy Traffic = 3 days

Full cure = 5 – 7 days                                               Full cure = 14 days

APPLICATION

Planning

1. Select appropriate PPE (personal protection equipment). Provide adequate ventilation. Refer to MSDS.
2. Work across the narrowest dimension of an area where practical.
3. Work to an exit from wet product.
4. To track coverage rate for each 3 gal. (11.4 liter) kit, after establishing room dimensions, before mixing commences, place a short piece of masking tape on the wall to correspond to the “distance” one kit should cover. Product should cover as a clear coat: approximately 100 – 150 ft² per gal. (9.3 – 13.9 m² per 3.8 liter) 10.7 – 16 mils OR As a thick build: 40 – 70 ft² per gal. (3.7 – 6.5 m² per 3.8 liter) 23—40 mils

Mask all areas requiring protection; product will stick to just about everything.

Mixing and handling

1. Organize mixing station that neither has to relocate, nor block the progress of application. Staging is critical so that Part A and part B are not confused with one another or mixed too far in advance. Once A and B are mixed, the catalyzed product should be placed on the floor immediately. If left in the pail too long, product will cure at an accelerated rate rendering it useless.
2. Pour 1 part B into 2 parts A. Note that kits are premeasured for convenience. Exercise care to avoid pouring product down the sides of the pail, as this will be difficult to mix.
3. Mechanically mix both parts A and B with “Jiffy” style mixer blade for 3 minutes at medium speed. Jiffy style mixer at medium speed will help prevent air entraining.
4. Pour contents completely out in a fairly long trail for application. Any unused portion left in the pail can cure at an accelerated rate rendering it useless.
5. Do not leave pail upside down to drain onto floor. Any unmixed portion of A or B that may have accidentally been placed onto side of pail can now drain down onto the floor, creating a spot that will not cure.
6. Clean out or replace mixing pails, mixer blades, and roller covers in a reasonable fashion, so that the chemistry of A and B remain consistent, especially over large projects.

Note: Due to its versatility within numerous systems, it is difficult to define 1 specific way of application of “Coats”. What follows are commonly utilized techniques. The sequence of application and the identification of “Coats” shall follow the ladder chart below. Begin with bottom box; proceed upward. For theDura-Kote Flakes and Dura-Kote Metallics be certain to refer to the appropriate TDS.

Ladder Chart for application of CoatsPrimer Coat

1. Spiked shoes are required throughout application.
2. Select spreader
3. For high build to cover small holes and imperfections in floor (e.g. blow-outs from carpet tack strip), a notched squeegee or gauge rake may be appropriate.
4. For a tighter coat, a squeegee or a roller ranging in nap size from mohair to 3/8” (9.5 mm) may be appropriate.
5. Rollers should be premium quality with phenolic core.
6. “De-fuzz” roller by wrapping tightly with masking tape and removing tape.
7. Large areas may require 18” (46 cm) rollers and wider squeegees.
8. Spread product evenly over area. Areas adjacent to walls may be “cut in” by brush.
9. Backrolling: After achieving the appropriate coverage, begin progressively backrolling Primer Coat. Roller covers will require replacing periodically to prevent catalyzed product from setting up on roller cover or contaminating more freshly placed material.

Note: Primer Coat may “stand alone” as a single coat depending upon application system selected, or applicator and client choice. Or a single coat of Dura-Kote Epoxy 100 may proceed to a Finish Coat of another Dura-Kote product as described later in this TDS (see ladder chart above.)

Top Coat

1. Clean: The Primer Coat should be cured, dry to the touch, and no longer tacky (refer to cure rates listed above as a guide) and then be screened with a 100 grit sanding screen on a rotational floor machine. This screening will ensure not only a good bond between coats, but also eliminate any debris or dust that may have settled onto the Primer Coat as it was curing. Follow screening with vacuuming. Follow vacuuming with a micro-fiber wipe with a solvent such as denatured alcohol or acetone.
2. Repeat all steps of application listed above. Planning, masking, mixing and handling are identical in Top Coat. Note: The Top Coat may complete the project, and does not necessarily require a Finish Coat (see ladder chart above.) However, for enhanced durability and chemical resistance, a Finish Coat may be selected. Additionally, a Finish Coat may become the “carrier” for slip resistant agents for areas that may become wet, oily, or greasy when brought into service.

Finish Coat There are several choices that have varying advantages for the Finish Coat:

• Surecrete DK 400 - Solvent-based Polyurethane
• Surecrete DK 400 WB - Water-based Polyurethane
• Surecrete DK 120 – Polyaspartic
• Surecrete DK 180 – Polyaspartic

The Top Coat should be screened with a 100 grit sanding disc on a rotational floor machine. This screening will ensure not only a good bond between coats, but also eliminate any debris or dust that may have settled as the primer coat was curing. Follow screening with vacuuming. Following vacuuming with a micro-fiber wipe with a solvent such as denatured alcohol or acetone. For specific directions on Finish Coat refer to the appropriate TDS.

Sacrificial Coat

A Sacrificial Coat is not required, but will add further protection to the finished product. The Sacrificial Coat may be applied at any step following a “stand alone” Primer Coat (see the ladder chart above.) SureFinish provides a protective sacrificial coat, a measure of slip resistance, and is available in gloss and matte, as a simple mop on product.