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  • Overview
  • Specs
  • Cure
  • Chemical
  • Application

NE5928 Expansion Joint Filler & Flexible Novolac Chemical Sealant

NE5928 is a two component 100% solids flexible sealant paste (novolac epoxy/urethane hybrid) designed for interior applications where a resilient flexible material that is chemically resistant is needed.  NE5928 is an excellent choice for interior expansion joint applications. This product has excellent chemical resistance and provides exceptional adhesion characteristics.

Recommended for interior expansion joints in general industry and chemical exposure areas for repairs of joints or cracks in concrete or masonry surfaces.

Available in 2 gallon and 10 gallon kits and a medium gray color when mixed.  This product is also available in a higher viscosity version that is more suitable for vertical applications, the NE5928V Vertical Joint Filler & Sealant.

TOPCOAT: None required. Many epoxy and urethane coatings are compatible.

PRIMER: None required

 Where is NE5928 Used?

  • Concrete & Masonry horizontal surfaces
  • Cracks & Joints
  • Areas subject to chemical exposure

Why NE5928 Joint Filler & Flexible Sealant?

  • Flexible joint filler – Elongation 43.4% at 70F (ASTM D-412)
  • Outstanding chemical and impact resistance
  • Novolac epoxy urethane hybrid formula
  • Excellent adhesion 420 psi
  • 100% solids with 0 voc
  • Low odor
  • Paintable surface


Solids By Weight 100%   By Volume 100%
VOC 0 g/L
Color Medium Gray after mixing
Recommended Thickness Variable between 1/2′ and 1-1/2″
Coverage per Gallon Depends on width and depth of joint
Packaging 1.25 gallon kit, 2.5 gallon kit
Mix Ratio 4:1 mix ratio by volume
Shelf Life 6 months in unopened container
Hardness Shore A = 80, Shore D = 53
Viscosity Mixed = 30,000 to 40,000 cps (typical)
 Abrasion Resistance 31.3 mg loss with a 1000 gram total load at 1000 revolutions with a CS10 wheel
 Flexural Strength 2945 (ASTM D-790)
 Tensile Strength 3,460 psi (ASTM D-412)
 Elongation at Break 43.4% at 70F (ASTM D-412)
 Impact Resistance Excellent
 Adhesion 420 psi (elcometer) – no delamination/concrete failure


Pot Life – 1-1/4 gallon mix 15 – 25 minutes
Recoat or topcoat 10 hours
Light foot traffic 24 hours
Full cure (heavy use) 2 – 7   days



 Ethyl alcohol C
1,1,1 Trichlorethane C
 Methanol B
 Xylene D
 Skydrol C
 10% Sodium Hydroxide D
 50% Sodium Hydroxide D
 10% Sulfuric Acid D
 70% Sulfuric Acid B
 10% HCI D
5% Acetic Acid D

Rating Key: A – Not Recommended, B – 2 Hour Term Splash Spill, C – 8 Hour Term Splash Spill, D – 72 Hour Immersion, E – Long Term Immersion.


PRODUCT STORAGE: Store product in an area so as to bring the material to normal room temperature before using. Continuous storage should be between 50-90°F. Avoid low temperatures and large temperature fluctuations in storage as these conditions could cause possible product crystallization.

SURFACE PREPARATION: All dirt, oil, dust, foreign contaminants and laitance must be removed to assure a trouble free bond to the substrate. We recommend that all loose concrete, previous patching compound or other foreign material be removed to leave a clean sound joint or repair area. For best results, when the depth of the repair are permits, a backer rod should be used to reduce the depth of the repair area. If the repair is too deep to prevent sag or slump, apply the material in multiple coats. For vertical surfaces, a higher viscosity version of this product is available, the NE5928V Vertical Joint Filler & Flexible Sealant.

PRIMER: No primer is necessary. This material is self-priming. However, any suitable primer can be used.

PRODUCT MIXING: It is important that the material be mixed well. Therefore take a few extra minutes to make sure adequate time has been taken to mix the two components together thoroughly. Improper mixing will cause an incomplete cure and soft spots in the repair area or joint. Mix four parts (by volume) part A to one part (by volume) part B in an oversized mixing container. Mix well with slow speed mixing equipment until totally streak free being sure to scrape the sides and bottom of the mixing container thoroughly. Avoid high speed mixing as this could force air into the product. Improper mixing may result in product failure.

For best mixing results and proper blending of parts A and B, recommend a Jiffy Mixer style drill mixer.

PRODUCT APPLICATION: Apply the mixed product by placing the material into the repair area or joint with a marginal trowel, putty knife or other suitable equipment. Remove any excess material with a putty knife or similar tool prior to curing. Alternatively, it may also be suitable to let the product become tack free in the joint and then using a razor scraper to cut off or shave the excess above the surface plane. Maintain temperatures within the recommended ranges during the application and curing process. When temperatures are lower, allow more time for this material to cure.

RECOAT OR TOPCOATING: No recoating or topcoating is necessary. However, if you opt to topcoat the applied joint compound, allow it to cure before topcoating. It is not necessary to prime over the joint compound prior to topcoating the joint compound. Many epoxies and urethanes can be used. In some instances, especially when excessive expansion joint movement is involved, topcoats may chip. However, most epoxy or topcoat products will adhere to the joint compound very well.

CLEANUP: Use xylol.

SURFACE CLEANING: Caution! Some cleaners may affect the color of the floor installed, test each cleaner in a small area, utilizing your cleaning technique. If no ill effects are noted, you can continue to clean with the product and process tested.

RESTRICTIONS: Restrict the use of the area to light duty use and non-harsh chemicals until the coating is fully cured. It is best to let the repair area remain dry for the full cure cycle.


  • Color stability may be affected by environmental conditions such as high humidity, chemical exposure or exposure to certain types of lighting such as sodium vapor lights or UV light sources.
  • Colors may vary from batch to batch. Gray color is not from our standard color chart.
  • Substrate temperature must be 5°F above dew point.
  • All new concrete must be cured for at least 30 days prior to application.
  • This product must be mixed very well before using. Improper mixing may result in product failure.
  • Test data based on neat resin
  • Physical properties listed on this technical data sheet are typical values and not specifications.

NOTICE TO BUYER: DISCLAIMER OF WARRANTIES AND LIMITATIONS ON OUR LIABILITY We warrant that our products are manufactured to strict quality assurance specifications and that the information supplied by us is accurate to the best of our knowledge. Such information supplied about our products is not a representation or a warranty. It is supplied on the condition that you shall make your own tests to determine the suitability of our product for your particular purpose. Any use or application other than recommended herein is the sole responsibility of the user. Listed physical properties are typical and should not be construed as specifications. NO WARRANTY IS MADE, EXPRESSED OR IMPLIED, REGARDING SUCH OTHER INFORMATION, THE DATA ON WHICH IT IS BASED, OR THE RESULTS YOU WILL OBTAIN FROM ITS USE. N0 WARRANTY IS MADE, EXPRESSED OR IMPLIED, THAT OUR PRODUCT SHALL BE MERCHANTABLE OR THAT OUR PRODUCT SHALL BE FIT FOR ANY PARTICULAR PURPOSE. NO WARRANTY IS MADE THAT THE USE OF SUCH INFORMATION OR OUR PRODUCT WILL NOT INFRINGE UPON ANY PATENT. We shall have no liability for incidental or consequential damages, direct or indirect. Our liability is limited to the net selling price of our product or the replacement of our product, at our option. Acceptance of delivery of our product means that you have accepted the terms of this warranty whether or not purchase orders or other documents state terms that vary from this warranty. No representative is authorized to make any representation or warranty or assume any other liability on our behalf with any sale of our products. Our products contain chemicals that may CAUSE SERIOUS PHYSICAL INJURY. BEFORE USING, READ THE MATERIAL SAFETY DATA SHEET AND FOLLOW ALL PRECAUTIONS TO PREVENT BODILY HARM.