How to Stop and Repair a Live Leak


Live leak and through-wall defects are quite common when it comes to the maintenance and repair of tanks and pipes. External and internal corrosion, aggressive chemicals and tough operating conditions contribute to the metal loss and wall thinning. Lack of prevention or timely maintenance might lead to delays in production, leakage of hazardous materials, and health and safety hazards. While conventional methods, such as welding and brazing, have historically been widely used to carry out the repairs on tanks and pipework, they lead to some consequential problems: bi-metallic corrosion in welds and seams, downtime, environmental damage, and hazardous conditions for the equipment and maintenance personnel.


In our previous block post “How to Repair a Cracked Engine Block”, we already demonstrated an application with cold-applied epoxy-based Belzona 1111. In this blog post we again demonstrate how Belzona’s cold-applied repair composites and cold bonding techniques make such repairs an excellent alternative to welding and other types of hot work. You will learn how to stop a live leak, and reinforce the thinning structure of a tank without taking it out of service, damaging its external/internal structure, or creating a hazardous environment for the personnel.


To carry out a live leak repair and to reinforce the structure of this tank, we used Belzona 1161 (Super UW-Metal), Belzona 9611 (ES-Metal), Belzona 9111 (Cleaner/Degreaser), a preformed metal plate and a few tools from our machine shop. First, we had to stop the flow. After thoroughly cleaning the surface around the damaged area, Belzona 9611, a fast curing paste grade material, was carefully kneaded and forced into the through-wall defect. A 2″ x 4″ stud and a Ratchet strap were used to secure the material in place until it fully cured.

For the reinforcement of the damaged area we used a preformed metal plate and Belzona 1161 as a bonding agent. The damaged areas on the tank as well as the mating face of the preformed plate were roughened using a grinder. Both substrates were then washed down with Belzona 9111 to remove all dirt, grease and other contaminants. Mixed Belzona 1161 was applied to all the prepared areas (on the tank and on the plate) and worked well into the roughened profile with a short bristled brush. While applying the mixed product onto the metal plate we created a build up (approx. ¼” (6 mm) thick) towards the center. This allows for displacing air while positioning the plate onto the tank wall. The plate was then pushed into position and forced down until Belzona 1161 exuded on each edge of the plate. The exuded material was immediately removed and used to chamfer the edges.


Drawing: Live Leak Repair with Belzona Cold Bonding


Step-by-Step Instructions of a Live Leak Repair with Belzona


Prepare the surface

Belzona Live Leak Repair: Prepare Surface

Using a file, roughen the surface around the live leak area.

Prepare Belzona 9611

Belzona Live Leak Repare: Prepare Belzona 9611

Knead Belzona 9611 to prepare it for stemming the live leak.

Apply Belzona 9611

Belzona Live Leak Repair: Apply Belzona 9611

Using a Belzona applicator, force the mixed material into the through-wall defect.

Allow the product to cure

Belzona Live Leak Repair: Secure the application area

Using a 2″ x 4″ stud and a Ratchet strap, secure the material in place until it is fully cured.

Remove once cured

Belzona Live Leak: Remove the wooden stud, strap and applicator

Once cured (approx. 1 hour later), remove stud, strap and applicator.


Roughen application area

Belzona Live Leak Repair: roughen the surface

Using a grinder, machine down the cured material, and roughen the bond area to remove all existing coating and achieve the best profile possible.

Clean the repair area

Belzona Live Leak Repair: clean the surface

Clean and degrease the bond area with Belzona 9111.

Apply Belzona 9111

Belzona Live Leak Repair: Apply Belzona 9111

Clean and degrease the bond surface of the preformed metal plate to remove all surface contaminants.

Mix Belzona 1161

Belzona Live Leak Repair: Belzona 1161

Transfer the entire contents of Belzona 1161 Base and Solidifier onto a Belzona mixing board and mix thoroughly until a uniform color, free of any streakiness, is achieved.

Apply Belzona 1161 onto tank

Belzona Live Leak: Apply Belzona 1161

Apply the mixed material directly onto the prepared surface, pressing down firmly to ensure maximum contact with the surface.

Apply Belzona 1161 to Plate

Belzona Live Leak Repair: Apply Belzona 1161 to plate

Apply a thin layer of the mixed material onto the prepared preformed plate, pressing down firmly.

Form a build up

Belzona Live Leak Repair: Form a Build Up

Form a build up approx. ¼” (6 mm) towards the center.

Position plate on tank

Belzona Live Leak Repair: Position Plate

Push the plate into position, pressing firmly in the middle to push the material towards the outside. This will help prevent air entrapment.

Remove Excess

Belzona Live Leak Repair: Remove Excess

Remove excess material immediately. Chamfer the edges of the plate with the exuded Belzona 1161.

Remove Tape

Belzona Live Leak Repair: Remove Tape

Remove the tape. The application is complete.


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