Sikagard® Duochem-7500

Meets the requirements of CFIA and USDA for use in food plants.

2 years when stored in original, unopened packaging.

Store dry at temperatures between 5 °C - 32 °C (41 °F - 90 °F)

~96 %

~95 %

< 50 g/L

~1600 cps (A+B Mixed)

* 24 mesh silica sand used for broadcasting.

** Note; standard 28 MPa (4,060 psi) concrete exhibits ~3,870 mg of loss when tested as per this ASTM procedure using H-22 abrading wheels. 

*** Failure occurs in underlying concrete.

Coefficient of Linear Thermal Expansion

Consult Sika Canada

Water Vapor Transmission

Water Permeance

A:B= 2:1 by volume

Condition product between 18 °C - 30 °C (65 °F - 86 °F) before use

Minimum  15 °C (59 °F)   Maximum 30 °C (86 °F)

NOTE: Observe minimum application temperature of 15 °C (59 °F) and product conditioning temperatures of 18 °C (65 °F) to  30 °C (86 °F) as high viscosity coatings exhibit reduced smoothing properties and greater tendency to display application marks at low temperatures.

Maximum 85% (during application and curing)

Substrate must be at least 3 °C (5 °F) above the dew point to reduce the risk of condensation, which may lead to adhesion failure or “blushing” on the floor finish. Be aware that the substrate temperature may be lower than the ambient temperature.

Minimum  15 °C (59 °F)   Maximum 30 °C (86 °F)

Do not apply while ambient and substrate temperatures are rising, as pinholes may occur.  Ensure there is no vapour drive at the time of application. Refer to ASTM D4263, may be used for a visual indication of vapour drive.

Moisture content of concrete substrate must be ≤ 4 % (pbw – part by weight) as measured with a Tramex® CME/CMExpert type concrete moisture meter on mechanically-prepared surface according to this product data sheet (preparation to ICRI / CSP 3 - 4). Do not apply to concrete substrate with moisture levels exceeding 4 % (pbw – part by weight) as measured with Tramex® CME/CMExpert type concrete moisture meter. If moisture content of concrete substrate exceeds 4 % (pbw – part by weight) as measured with Tramex® CME/CMExpert type concrete moisture meter, use Sikagard® WDE Primer, Sikafloor®-1610 or Sikafloor®-81 EpoCem®CA or Sikafloor® 22NA PurCem® or 24 NA PurCem® on horizontal surfaces and Sikagard®-75 EpoCem®CA on walls and overhead applications.

When relative humidity tests for concrete substrate are conducted per ASTM F2170 for project specific requirements, values must be ≤ 85 %.

If values exceed 85 % according to ASTM F2170 use Sikagard® WDE Primer, Sikafloor®-1610 or Sikafloor®-81 EpoCem®CA or Sikafloor® 22NA PurCem® or 24 NA PurCem®. ASTM F2170 testing is not a substitute for measuring substrate moisture content with a Tramex® CME/CMExpert type concrete moisture meter as described above.

Drying Times

Curing times will vary according to air and substrate temperature and relative humidity.

Protect from dampness, condensation and water contact during the initial 72 hour cure period.

Mechanical, chemical and physical properties will be fully achieved at full cure.

Note: If the Waiting / Overcoating Time has passed, the previous coat must be lightly sanded, to remove all gloss; vacuum cleaning and solvent wiping will be necessary to remove all traces of dust. The surface should be a uniform dullness, with no gloss present after clean-up and before applying the next coat.

Concrete Substrate / Smooth Coating

Sikagard® Duochem-7500 maximum build on vertical surfaces 7 mils w.f.t. per coat. Three (3) coats may be required to produce a smooth coating vertically.

Concrete Substrate / Broadcast Surfacing

Steel Substrate / Smooth Coating

Sikagard® Duochem-7500 maximum build on vertical surfaces 7 mil w.f.t. per coat. Three (3) coats may be required to produce a smooth coating vertically.

Steel Substrate / Broadcast Surfacing

For Optimum Chemical Resistance for all Systems

Actual coverage rates and material consumption will depend upon porosity and profile of substrates. Allowance must be also made for variation in film thickness or number of coats required to achieve opacity.  Test sections are recommended to establish correct coverage.

Mix Ratio:  A:B 2:1 by volume.

Do not hand mix Sikagard® or Sikafloor® materials. Mechanically mix only.

Do not thin this product. Addition of thinners (e.g. water, solvent, etc.) will slow cure and reduce ultimate properties of this product. Use of thinners will void any applicable Sika® warranty.

Pre-stir Components A and B separately, making sure all solids, are evenly distributed and uniform consistencies are achieved.  Do not allow mixed material to stand and settle. Failure to pre-stir and keep product agitated will result in variation in gloss levels appearance and performance.  Empty Component B (Hardener) in the correct mix ratio into Component A (Resin) or empty Component A into a suitably sized and clean pail and add Component B in the correct ratio. Blend the combined components thoroughly at low speed (300 - 450 rpm) for at least three (3) minutes using a drill fitted with an Exomixer® or Jiffy type paddle suited to the dimensions of the mixing container and keep the mixing paddle in the mix to minimize entrapped air. Take care not to introduce any air bubbles while mixing. Make sure the contents are completely mixed to avoid any weak or partially cured spots in the coating. During the mixing operation, scrape down the sides and bottom of the container with a flat or straight edge trowel at least once to ensure complete mixing. When completely mixed, Sikagard® Duochem-7500 should be uniform in appearance and consistency.
Important: Mixing attempted at material and ambient temperatures below 18 °C (65 °F) will result in a decrease in product workability. Do not mix more material than can be applied within the working time limits (i.e. Pot Life) at actual field temperature. Never use a thickening agent such as Sikafloor® Extender T, Cabosil or any other to increase product viscosity as this will greatly reduce chemical resistance.

See Consumption section of this product data sheet above for number of coats, coverage rates and specific application thicknesses recommended.

Concrete:
Primer Selection: Concrete primer selection is based on environmental and substrate conditions at the time of installation. Sikagard® Duochem-7500 is compatible with Sikagard® WDE Primer (low temperature cure and moisture tolerant epoxy primer), Sikafloor®-1610 (standard set, moisture tolerant epoxy primer), Sikafloor®-156CA (standard set epoxy primer) and Sikafloor®-165 FS (fast set epoxy primer). Consult the most recent issue of concrete primer product technical data sheet for additional information. Contact Sika Canada Technical Services for advise and recommendations.

Smooth Coating:
Primer Coat: Apply selected Sikagard® or Sikafloor® primer onto concrete substrates using a brush, roller or squeegee to a uniform coverage without ponding.
1st Coat: Once the primer is tack free apply Sikagard® Duochem-7500 using a brush, roller or squeegee to a uniform coverage without ponding.
2nd Coat: Once first coat is tack free, apply a second coat of Sikagard® Duochem-7500 using a brush, roller or squeegee to a uniform coverage without ponding.

Broadcast Build-Up System:
Primer Coat: Apply selected Sikagard® or Sikafloor® primer onto concrete substrates using a brush, roller or squeegee to a uniform coverage without ponding.
Broadcast Coat: Once the primer is tack free apply the broadcast coat of Sikagard® Duochem-7500 using a notched squeegee or trowel and backroll to a uniform coverage. Broadcast the selected aggregate (shape and size to be selected to meet the end user’s traction requirements) into the wet resin to rejection.

Top Coat: Once the broadcast coat has sufficiently cured to allow foot traffic, sweep-up and vacuum-off all loose, unbonded sand. Apply the top coat of Sikagard® Duochem-7500 using a squeegee, followed by back rolling to provide a uniform texture and finish.
Steel:
Priming, consolidating or sealing of common steel substrates with a Sikagard® or Sikafloor® primer is not usually required under typical circumstances. However, due to variations in steel quality, surface condition, surface preparation and ambient conditions, reference test areas are recommended to determine whether priming is required to prevent the possibility of debonding, blisters, pinholes or other defects. Consult Sika Technical Sales for advice.
Application of Sikagard® Duochem-7500 onto properly prepared steel surfaces is typically the same procedure as outlined above for smooth coatings and broadcast build-up systems onto concrete, excluding the use of a Sikagard® or Sikafloor® primer, unless determined otherwise.

Clean all tools and equipment immediately after use with Sika® Epoxy Cleaner.  Once hardened, material can only be removed mechanically.