Sikaflex® SL 2

• ASTM C 920, Type M, Grade P, Class 25, Use T, NT, M, A, O*, and I
• Federal Specification TT-S-00227E, Type I, Class A
• Corps of Engineers CRD-C-506, Type I, Class A
• Canadian Specification CAN/CGSB 19.24-M90, Classification MCG-1-40-B-L, No. 81031
• CFI accepted
  * Refer to substrates in Where to Use.

Sikaflex® SL 2 is a multi-component polyurethane that cures by chemical reaction after proper mixing.

Parts A and B: 15 months when properly stored

Store in unopened containers in cool, clean, dry area out of direct sunlight. Elevated temperatures will shorten shelf life.

Nil

-40 to 180°F (-40 to 82°C)

Joint Width and Sealant Depth
 

Working Times

Meters per Liter

• Do not allow Sikaflex® SL 2 sealants to come into contact with alcohol-based materials or solvents.
• Do not apply polyurethane sealants in the vicinity of uncured silicone sealants or uncured Sikaflex® HY 150.
• When Sikaflex® SL 2 is to be used in areas subject to continuous water immersion, cure for 14 days at 70 °F (23 °C). Allow longer cure time at lower temperatures. Always use Sika® Primer-173.
• Do not use it in swimming pools or other submerged conditions where the sealant will be exposed to strong oxidizers. Avoid submerged conditions where water temperatures will exceed 120 °F (58 °C).
• For slopes up to 12% use Sikaflex® SL 2 Slope Grade. For slopes over 12% use Sikaflex® NP 2 sealant.
• Backer rods, joint fillers, or bond breakers must be tight to the sides of the joint to prevent loss of sealant through the bottom.
• For joints subject to puncture by high heels or umbrella points, a stiffer or higher-density backup material is required. Cork or rigid non-impregnated cane-fiber joint fillers are suitable. Separate materials from the sealant by a non-adhering bond breaker (polyethylene tape).
• Do not use other caulks or sand as a bottom bed in a joint.
• Do not install when rain is expected before the sealant reaches the initial cure (about 12 hours).
• Units of Sikaflex® SL 2 are premeasured; do not use partial units.
• Sikaflex® SL 2 may yellow in the presence of unvented artificial heat; this is a surface phenomenon that does not affect sealant performance.
• Use only Sikaflex®-900 color packs intended for use with Sikaflex® SL 2.
• Proper application is the responsibility of the user. Field visits by Sika personnel are for the purpose of making technical recommendations only and not for supervising or providing quality control on the job site.

Joints must be clean and dry. Joint surfaces must be structurally sound, fully cured, and free of all loose aggregate, paint, oil, grease, asphalt, wax, mastic compounds, waterproofing compounds, form-release materials, curing compounds, or any other contaminants.

New Concrete
Remove all loose material from joints by wire brushing. Sandblast surfaces in contact with form-release agents. Fresh concrete must be fully cured. Laitance must be removed by abrading.

Old Concrete
For previously sealed joints, remove all old material by mechanical means. If joint surfaces have absorbed oils, remove sufficient concrete to ensure a clean surface.

Priming

1. For most applications, priming is not required; joints subject to periodic water immersion, however, must be primed with Sika® Primer-173. On surfaces other than concrete, conduct a test application to verify adhesion.
2. Apply primer in a thin, uniform film. Avoid buildup of excess primer.
3. Avoid applying primer beyond joint faces. To minimize the contamination of adjacent surfaces, apply masking tape before priming and remove before the sealant has begun to thicken and set.
4. Allow approximately 15 – 30 minutes drying time before applying sealant (primer should be tack-free). Priming and sealing must be done on the same day.

1. Sikaflex® SL 2 is a multi-component system with a configuration of Part A, Part B, and sometimes a color pack.
2. Part B comes in a pouch and is usually squeezed into the resin.
3. Part B must be mixed thoroughly with Part A. Before adding pigment, scrape the sides of the container to ensure the complete mixing of Parts A and B. With a slow-speed drill and a sealant mixing paddle, mix for 4–6 minutes. Keep the paddle blade below the surface of the sealant to avoid whipping air into the sealant.
4. Transfer the entire contents of one Sikaflex®-900 color pack pigment can into the mixed Part A and B. Use a spatula or knife to remove all the pigment from the container. Continue mixing with a slow-speed drill and slotted paddle until the color is uniform. During the process, scrape the sides and bottom of the mixing container several times to obtain a complete mix.
5. 3-gallon (11.37 L) unit: Use 2 Part B and 2 pigment containers for each Part A container. Mix as instructed under a 3/2 gallon (5.7 L) unit.
6. The pot life of mixed Sikaflex® SL 2 is influenced by temperature. See Pot Life for specific data. Sikaflex®-905 accelerator may be added to adjust the initial cure rate.

1. All caulking and sealing should be performed when temperatures are above 40 °F (4 °C); any moisture or frost on surfaces will adversely affect adhesion.
2. Fill joints from the bottom; avoid bridging the joint, which may form air voids.
3. For large joints, the self-leveling grade may be poured directly from the can.
4. For smaller joints and all slope-grade applications, fill the joint by flowing the sealant from a bulk-loading gun.
5. Light tooling of the slope-grade sealant is recommended to smooth out ripples. On sloped surfaces, tool from the lowest point to the highest. Do not use soap or solvent.

Curing

Cure time will vary with humidity and temperature. Initial cure is within 24 hours and complete cure takes approximately 7 days. Allow 14-day cure at 70 °F (23 °C) before water immersion. Cure rates are dependent on temperature and humidity. Protect joint from dirt and traffic until cured. See Pot Life for the use of the Sikaflex®-905 accelerator.

1. Immediately after use and before the sealant has cured, clean equipment with SikaSwell®-990 or xylene.
2. The cured sealant may be removed by cutting with a sharp-edged tool. Remove thin films by abrading.