Transformer & Substation Painting

How to Avoid Costly Downtime?

The answer is simple. Keep it clean to keep it working!

Service interruptions and downtime are expensive, do damage to your reputation and disrupt your customers. They are also almost completely avoidable.

Permashell specializes in cleaning and painting high voltage electrical equipment. We have been serving the Canadian utility industry for over 20 years. We understand the safety and operational requirements of substation work and our personnel are trained for work in energized substations.


Electrical transformers are designed for 50-year lifecycles. But not their OEM paint jobs. They need to be repainted long before that. Cutting corners increases the risk of operational failures and should not be an option.

Electrical transformers represent such a large capital investment cutting corners is not an option. Add to that the risk of operational failures and there is only one real option.

Spray Painting or Flow Coating?

Spray painting just doesn't get the job done. In fact, spray painting may not cover any more than 50 to 75% of radiator surfaces, camouflaging the corrosion damage and leaving your operations vulnerable to electrical failure.

Flow Coating is the only completely effective way to do the job. It is also the most cost-effective over the 50-year lifecycle.

Flow Coating 100% Coverage

Flow Coating provides complete coverage of 100% of radiator surface area, including the backsides and restricted surfaces of the fins, tubes and stabilizer bars, as well as the joints, seams and hidden areas deep within the radiator banks that are not accessible by any other painting method.

Similar to a factory immersion finish, Flow Coating is applied on location in the substation without dismantling the equipment and if necessary with little or no interruption of service.

Rust Treatment

Where rust has formed on inaccessible radiator surfaces, a special rust removal and neutralizing solution is applied by Flow Coating to chemically neutralize the rust, and passivate it for encapsulation with subsequent coats of corrosion and weather resistant paint.

Treating Old Coatings and Bare Metal

Also, where old coatings are blistered, flaking and peeling on inaccessible surfaces, they are stripped from the tube surfaces with a heated chemical stripping compound by the Flow Coating process. This is followed by treatment of the bare metal surfaces with a chemical surface treatment solution, and refinishing with multiple coats of corrosion and weather resistant paint, to provide a replacement coating system that will be trouble-free for as long as possible.

Where equipment is exposed to contamination with soluble salts such as chlorides, sulfates or nitrates, invisible residues left on surfaces will absorb moisture through coating films, causing blistering and premature coating failure. Decontamination with a soluble salts removal solution is specified for insurance against salt-induced coating failure.


Most substation structures and transmission towers are constructed of hot-dip galvanized steel. Depending on the quality of the galvanizing and the environmental exposure, galvanizing generally lasts from 15 - 50 years before the zinc coating is eroded to the point where corrosion of the base steel begins to take place, and it is very important to recognize when this begins to occur. A protective layer of paint over aged galvanizing acts as a barrier between the remaining zinc and the environment, slowing down the rate at which the zinc is sacrificed, and allowing it to continue to protect the steel substrate for a much longer time.

Changes in the appearance of the galvanizing are an indication of its life expectancy. As galvanizing weathers, it loses its brightness and darkens due to the formation of zinc corrosion on the surface. When it becomes dark grey, it is a general indication that much of the zinc layer has been eroded away. This is the signal that maintenance painting is due, because surface preparation, which is a major factor in the cost of painting these structures, is fairly moderate at this point.

When the surface becomes reddish-brown, the zinc-iron alloy layer, that was formed between the zinc and the the steel substrate, has been exposed by the erosion of the zinc, and a new barrier is needed to avoid jeopardizing the integrity of the structure.

Doing maintenance at the right time has measurable and significant cost savings. Maintenance painting at the right time extends the protection of the original galvanizing, and if done properly with the appropriate coatings, doubles the service life of the structure. Repeated maintenance painting later on will further extend the service life of the structure.



When flashovers occur, it can cost much more than replacement or repair of the damaged insulators or bushings. Flashovers can cause sudden, unexpected power outages that can result in production stoppages or interruptions of customer services that can easily cost thousands or even millions of dollars.

Flashovers due to surface contamination and wildlife contact can be prevented by the application of silicone High Voltage Insulator Coating on the surfaces of insulators and bushings.

Proper surface preparation is essential for good adhesion of HVIC. If necessary, Permashell cleans insulator and bushing surfaces by gently blasting with a very soft, fine powdered limestone abrasive that does not damage glazed surfaces. The light dust film of this non-toxic, agricultural-grade limestone powder is safely blown away with high-pressure air. And unlike corncob abrasive that is often used, our cleaning compound leaves no corrosive residue on other substation apparatus, and no mess in substation yards.

Safe. Clean. Secure.


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