Perma Silicone Seal GP-621


Perma Silicone Seal GP-621 is one part moisture curing silicone sealant suitable for use in a broad range of applications. It is easy to apply and offers excellent adhesion to a variety of non-porous substrates such as glass, glazed ceramic tiles and aluminum.

Perma Silicone Seal GP-621


    1. One part sealant, no mixing etc. is involved hence easy to use.
    2. Good weather resistant, it is least affected by sun, rain, ozone and temperature extremes.
    3. Long working life, it stays flexible from -24 to 110°C.
    4. It can be applied in any season.

Make sure that the joints to be sealed are designed correctly. Correct design of the joint minimizes the stress on the sealant. The joint should be clean, sound and dry. Solvent wash the entire surface using a brush with an oil free solvent. Use masking tape on either sides of the joint. Masking tape should be removed immediately after a bead is completed before a skin begins to form. Apply sealant to a dry and clean surface using a sealant cartridge gun. Do not break the cartridge seal until just before use. Tool the joint if necessary and remove the masking tape. Tooling should be completed in one continuous stroke.


      1. This sealant is not recommended in aquariums.
      2. It should not be used for structural glazing. Not recommended for surfaces which require painting.
      3. Not to be used on concrete, marble, limestone and brick.
      4. Not recommended for joints below ground level.


Flow Sag OR Slump : NIL
Skin-Over Time : 10 to 12 minutes
Working Time : 10 minutes
Tack Free Time : 20 minutes
Specific Gravity : 0.98 ± .2%


Hardness Shor A : 16
Tensile Strength : 1.9Mpa
Elongation : 470%
Modulus at 100 % MPA : 0.38


Direct contact of the uncured sealant irritates eye and the skin. Over exposure to the sealant vapor may cause irritation to eyes, nose and throat. Avoid direct contact. Use adequate ventilation, use hand gloves. In case of eye contact, flush eyes with water for 15 minutes and seek medical attention. In case of skin contact remove the product from the skin and flush with water. The sealant releases acetic acid odor during cure. KEEP OUT OF REACH OF CHILDREN.


Perma Silicone Seal GP-621 is available in 280 ml cartridge


Perma Silicone Seal GP-621 can be stored for 12 months, if it is kept at a temperature below 27°C


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.