ISO QMS Certified
"Our Science ... Your Success"

Weld Sealing – Don’t risk it, wick it!

Weld porosity

Welding is used in many industries for structural joining, often a water tight seal of the welded joint is not a requirement.  In other industries such as fire protection, a complete seal of a weld is critical to ensure a leak free sprinkler system.

Weld porosity leaks can be very small and difficult to detect without pressurizing a system.  These micro porosities can go undetected for long periods of time.  The pin-prick leaks can be so small that they appear to be condensation on the pipes.  These types of leaks can cause ceiling damage and offer mildew and mold a fantastic opportunity to proliferate.  Others leaks can drip only once the system is pressurized, causing damage to ceilings, floors, furnishings and personal property.

Anaerobic weld sealants are very low viscosity, wicking grade sealants which fill all voids or imperfections and cure to form a permanent plastic seal that prevents potential leaks.  Cure is initiated by the absence of air and the presence of metal, and begins to occur when the sealant wicks into the imperfections.

To use, heat up the weld (with a hot air gun or even just a hairdryer), then apply the adhesive with a brush, swab or rag and allow the sealant to wick into any voids. As the metal cools down and contracts, the weld sealant will be drawn in and cure inside the microscopic pores.

The risk of a leaky system greatly outweighs the efforts to protect every weld.  Using a weld sealant is less costly than pressurizing a system to detect the porosity leaks and provides the added protection of corrosion prevention.

Experienced fire protection professionals agree, Don’t risk it – wick it!

For further help and advice, please contact Permabond.