Perma Neutral Plus Silicone Seal NP – 623


Confirms To ASTM C 920-86.


Perma Neutral Plus Silicone Seal NP-623 is a high performance cost effective, one component adhesive/sealant offering long term durability in a range of general sealing, general glazing, waterproofing application. The sealant exhibits excellent adhesion to a wide range of substrates, such as concrete, brick, aluminum, glass, wood, plastic etc.

Perma Neutral Plus Silicone Seal NP – 623


  1. One part sealant, hence ease of application.
  2. Neutral cure, will not corrode metals.
  3. It is highly flexible and is capable of withstanding movement in and around the joint.
  4. Excellent adhesion to vinyl, wood, steel, aluminum, glass and plastic.
  5. Useful in Sealing Electrical Equipments.
  6. It is waterproof and weatherproof.
  7. VOC Compliant.


Perma Neutral Plus Silicone Seal NP-623 is supplied as ready to use cartridges. The sealant flows readily when extruded through a caulking gun. The paste like consistency makes it easy to work. Spatula or a paddle can be used for tooling the surface. The cure progresses inward from the surface. The sealant achieves tack free skin in 15- 20 minutes when the temperatures are around 24° C with 50 percent relative humidity. Tooling should be done before skin starts to form and it should be completed within 10 minutes of extension. All masking tape should be removed before tack free skin forms.


  1. Do not use for structural glazing
  2. Do not use in areas where continuous water immersion is expected.


Uncured Specific Gravity : Clear- 1.00
Sag or Slump : NIL
Tack free time : 15 Minutes
Cure time at 24°C and 50% RH 3/8″ thick Extrusion Rate : 24 hrs
Cured – Physical : 390g/min
Durometer Shore A Hardness : 23 points
Tensile strength : 220 psi
Elongation : 500 %


The table below provides a guide to the linear metres per cartridge for various joint sizes.
NOTE: Actual sealant usage will vary depending on such factors as joint geometry, backer rod placement, tooling and wastage at the job site.

 Joint Depth (mm) Joint Width (MM)
6 8 10 12 15 20 25
6 8.3 6.2 5 4.1 3.3 2.5 2.0
8 N/O 4.6 3.7 3.1 2.5 1.8 1.5
10 N/O N/O 3 2.5 2.0 1.5 1.2
12 N/O N/O N/O 2.0 1.6 1.2 1.0

N/0: Not optimum joint design for best sealant performance.


Direct contact of uncured sealant irritates eyes and may irritate skin. Overexposure to vapour may irritate eyes, nose and throat. Avoid eye and skin contact. Use with adequate ventilation. Do not handle contact lenses with sealant on hands. In case of eye contact, flush eyes with water for 15 minutes. Obtain medical attention. In case of skin contact, remove from skin and flush with water. Keep out of reach of children. For safe handling information on this product, consult the material safety data sheet (MSDS).


Perma Neutral Plus Silicone Seal NP-623 available in standard size 280 ml plastic cartridges.


Perma Neutral Plus Silicone Seal NP-623 has a shelf life of 12 months if stored in original unopened containers in a cool and dry place. Temperature should not exceed 27°C for prolonged periods.


PERMA warrants that all products are free from any defects of manufacture and comply with the specifications given in their respective technical data sheet. No warranty can be given as to the results of use because conditions of use, such as site conditions, surface preparations, workmanship, weather, structural issues and other factors are beyond the control of PERMA. Purchaser agrees to seek the advice of qualified professionals to carry out tests & take trials to determine the suitability of products for their intended purpose prior to full scale usage of PERMA products and assumes all risks.

The company does not assume any liability for unsatisfactory results, arising from the use of our products. Purchaser’s sole liability is limited to replacement of product or refund of the purchase price paid if any product proven defective. No other warranties, express or implied, shall apply including any warranty of merchantability or fitness for a particular purpose.
PERMA shall not be liable for any consequential damages arising from the use of our products for unsatisfactory results.

The information supplied in this datasheet is based on our experience through extensive research and is given in good faith in order to help prospective users. We reserve the right to update the information provided in our technical data sheet at any time without prior notice within the scope of technical progress or new developments.