Product Data Sheet Safety Data Sheet Show all documents
Sikasil®-728 NS

Sikasil®-728 NS

Non-sag, ultra low modulus, highway/parking garage, neutral cure silicone sealant

Sikasil®-728 NS is a high performance, non-sag. one-component , ultra low modulus elastomeric, neutral cure silicone sealant. Meets the requirements of ASTM D-5893: ASTM C-920, Type S, Grade NS, Class 100/50, Use NT, T, M, G, A, O with ultra low Shore Hardness: TT-S-00230C, Type II, Class A; Class A.

  • Durable
  • Ideal for cold climates
  • Excellent flexibility for extreme high and low temperature conditions
  • Excellent flexibility for dynamic joint movement
  • Bonds to most substrates without priming; best performance obtained in horizontal joints when primed
  • Ready to use, labor cost reduction
  • Non sag, excellent for vertical joints
  • All season ease of application
  • Excellent for use on all types of concrete joints
  • Jet fuel resistant
  • Resistant to road salts
Product Data Sheet Safety Data Sheet Show all documents

Usage

Construction Application
  • Highway joints
  • Bridges
  • Stadiums
  • Parking garages
  • Plaza decks
  • Driveways
  • Decks
  • Expansion joints
  • Saw cut joints
Substrate
  • Concrete, steel, glass, aluminum, ceramic, masonry, brick, stone and granite
 

Advantages

  • Durable
  • Ideal for cold climates
  • Excellent flexibility for extreme high and low temperature conditions
  • Excellent flexibility for dynamic joint movement
  • Bonds to most substrates without priming; best performance obtained in horizontal joints when primed
  • Ready to use, labor cost reduction
  • Non sag, excellent for vertical joints
  • All season ease of application
  • Excellent for use on all types of concrete joints
  • Jet fuel resistant
  • Resistant to road salts

Packaging

4.5 gal (17 l) in a 5 gal pail

52 gal (197 l) in 55 gal drum

29 oz. cartridge/12 per case

Color

Limestone and Charcoal Gray

Product Details

Product Information

Chemical Base

Neutral cure silicone

Shelf Life

When stored in the original, unopened containers at or below 90 °F (32 °C), shelf life is one year. A product skin may form in pails and drums, remove prior to use.

Storage Conditions

Store in unopened containers at temperatures at or below 90 °F (32 °C).

Volatile organic compound (VOC) content

1.64 % by wt., 21 g/l, 0.18 lb./gal.
Technical Information

Shore Hardness

50

Shore OO (after 7 days)

5-10

Shore A (after 7 days)

Tensile Strength

175 psi (1.20 MPa)

(ASTM D-412)

Tensile Stress at Specified Elongation

35 psi (0.24 MPa) at 100 % elongation

(ASTM D-412)

Adhesion in Peel

~7 N/mm (40 lbf/in) on mortar substrate

(ASTM C-794)

Movement Capability

+100 % / −50 %

(ASTM C-719)

Resistance to Weathering

Excellent

Service Temperature

−80 °F min. (-62 °C) / +350 °F max. (177 °C)

Joint Design

Joint Design: The number of joints and the joint width should be designed for a recommended joint movement of +25 % and -25 % at time of installation. The depth of the sealant should be 1/2 the width of the joint. The maximum depth is 1/2 inch (13 mm) and the minimum is 3/8 inch (10 mm). For joints greater than 1 inch (25.4 mm), do not exceed 1/2 inch (13 mm) in depth.

  

Joint Backing: To control joint depth, use closed cell polyethylene or non-gassing polyolefin backer rod. If joint depth does not allow for backer rod, use polyethylene bond breaker tape to prevent three-sided adhesion. Closed cell backer rod should be 25 % larger than joint width; do not compress more than 40 %.

 

Application

Application Information

Backing Material

Use closed cell, polyethylene foam backing rods 25 % larger than the joint width. If the joint depth does not allow for a backer rod, use polyethylene bond breaker tape to prevent three-sided adhesion.

Sag Flow

none

(ASTM D-2202)

Cure Time

1/16” / 24 hours

(MNA Method)

Skin Time

15–25 minutes

(77 °F (25 °C) / 50 % R.H.) (MNA Method)

Tack Free Time

30–40 minutes

(77 °F (25 °C) / 50 % R.H.) (ASTM C-679)
Consumption

Coverage

1 gallon: Yield in Linear feet

Width/Depth1/4''3/8''1/2''
1/4''307.9

3/8''

205.3136.8
1/2''153.9102.677.0
3/4''102.668.451.3
1''38.5
1.25''30.8
1.5''25.7

29 oz Cartridge: Yield in Linear feet

Width/Depth1/4''3/8''1/2''
1/4''69.8

3/8''

46.531.0
1/2''34.923.317.4
3/4''23.315.511.6
1''8.7
1.25''7.0
1.5''5.8
Application steps

SUBSTRATE PREPARATION

The substrate must be clean, dry, frost free, sound and free of any oils, greases or incompatible sealers, paints or coatings that may interfere with adhesion.
 

Porous Substrates – clean by mechanical methods to expose a sound surface free of contamination and laitance.
 

Non-porous substrates – for cleaning non-porous substrates, use two rag wipe method using xylene or an approved commercial solvent. Allow solvent to evaporate prior to sealant application.

    

Primer

Sikasil®-728 NS is designed to obtain adhesion without the use of a primer; however, best results are obtained when horizontal joints are primed. Test by applying the sealant and/or primer sealant combination to confirm results and proposed application methods. Refer to Technical Data Sheet for Sikasil Primer 2100 and contact Technical Service for additional information.

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