Transformer Painting in a Nutshell

This is a picture of a transformer that R&H painted in Minnesota. It has 3 large radiator banks, and is located at a wind energy farm in southern MN.

Large substation transformers are a major capital expense for transmission and distribution companies. It is commonplace for companies to plan on using them for decades, sometimes even longer. If customer demand requires replacing a transformer with a larger one, often times the small one will be sold on the secondary market, and installed by another utility. While the chassis and other key components of a transformer are built to last, the paint coatings may not be. Regularly scheduled maintenance is an important function in the transformer lifecycle, and that should include inspection of coatings and timely maintenance painting as required.

This is a picture of the top of a transformer. Most of the paint has worn off, and large patches of orange are starting to show through.

This transformer is overdue for painting. While the sides of the unit do not show much weathering, you can see the top is much worse. This is very common and has to do with the top typically getting the most sunlight, and also pools of rain water accelerating the wear. From this point on, surface preparation costs are going to skyrocket. There are already some areas progressing from “tight rust” to “loose rust”. This raises the bar significantly in terms of surface prep required.

For the most efficient use of your maintenance budget, I recommend getting a maintenance coat before your equipment is showing major signs of corrosion. We can go further in depth on this at a later date, but the basic reason is as follows. In any given painting project, roughly half the money spent is allocated towards surface prep, aka cleaning. Removing rust, grease, failed coatings, and any other surface contaminants is absolutely mandatory before any new paint can be applied. The worse shape your transformer is in, the more work is required to get it “paint ready.” While a little grease or a lot of grease maybe doesn’t drastically affect the contract cost, the level of corrosion usually does.

 

Ideally, you should schedule painting before corrosion has taken over, or as soon as you see the slightest orange shades starting to show in the existing paint film. That way surface prep can be kept to a minimum, and involves just “cleaning” similar to cleaning dirty dishes. Now on the other hand, if you try to stretch out the maintenance schedule, you’re not necessarily saving money. Every day/week/month/year that goes by, increases your costs of surface prep. Ferrous metal surface prep basically starts out at just washing and scrubbing, and progresses up (in terms of cost) ending with sand blasting. Staying closer to the “washing” end up the spectrum will ensure you’re getting the most for your maintenance dollar. Let it go too long, and create too much loose rust, and you can literally get to the point where you might as well scrap it and buy a new transformer. Chances are it’s leaking all over the place anyhow.

 

While painting a transformer is not extraordinarily difficult, there are several key items that must be accounted for. The first item being safety! There are inherent risks involved with substation work, and it’s crucial that they are mitigated as much as possible.  Working in and around high voltage equipment does not provide for much room to “learn as you go”. Make a wrong move and it’s over. Literally and figuratively!

 

Most of the risk can be eliminated by following proper shut down and grounding out procedures. This is typically performed by the owners trained electrical personnel. Then its up to the painting contractor to perform their job satisfactorily. Proper training and use of lanyards, harnesses, ladders, and more is an integral part of providing a quality product and making sure everyone goes home safely.

 

While painting the body of a transformer is fairly straightforward, the radiator banks are another story. There is really only one way to accomplish it, while in the field, and that is by flow coating. Flow coating will give you a finished product very similar to if you disassembled the radiators, and hauled them to a shop to have them dipped. It is the only way (so far) to make sure that every single nook and cranny in the radiator gets coated.

 

Doing a good job of it requires extreme care, and due diligence on the part of the contractor. If the coating was to get applied too heavily, it could have a noticeable effect on the radiators ability to cool off the oil. In that case, your looking at major downtime, and major expense! If it’s too thin, it won’t last as long as it should. There aren’t really any good tools for measuring mil thickness of the paint, when you can’t even fit your arm in between the fins. Achieving the proper thickness is based solely off experience, and knowing what to look for (how the paint behaves) throughout the process. So it’s a delicate balancing act that requires a lot of experience by the applicator. 

So while transformer painting definitely isn’t rocket science, you’ll want to make sure that your projects are being handled by someone with experience. As you know, an ounce of prevention is worth a pound of cure and, its hardly worth painting to begin with if you don’t have a solid plan of action, and full faith that your contractor can take care of your needs.

 

Thank You, Bryce Raisanen
Feel free to like, share, comment, ask questions!

I’ve shortened the video below, to show just the cleaning portion of a transformer job. Responsible management got the painting scheduled before it was in too rough of shape, and with four people (I think?) we were able to complete all of the surface prep in short order.

This is a picture of a transformer that R&H Painting painted near Minneapolis, MN.

This is a picture of a large substation transformer that R&H painted near Blaine, MN.

 

 

This is another picture of the transformer that R&H painted nearby Blaine, MN.

 

This is a picture of a new paint job we put on a transformer in MN. We used a high gloss industrial coating from Induron coatings.

 

This is a finished picture of a large transformer that R&H painted in the fall of 2015 in central MN, not far from Minneapolis.

Fertilizer Blending Tower Maintenance

Minnesota Fertilizer Tower PaintingDo you own a large fertilizer blending tower in MN or the Midwest? It doesn’t really matter if its a Waconia, a Yargus, a Sackett, or any other brand. They all live a similar lifestyle.  When’s the last time you climbed to the top and gave it an inspection? It goes without saying, the conditions in Minnesota can be hard on metal structures. If your tower is over five years old, you had better be keeping an eye on it!

Just this past fall I inspected one in central MN, not far from Brainerd. The Co-op had just had a new roof installed on it at a cost of over $40,000. The site manager told me it was only 7 years old. Value engineering in the manufacturing department, combined with Minnesota weather and harsh chemicals, generates a devastating combination of rust and general corrosion.

The Roofs Go First

Minnesota Fertilizer Tower Painting

Large hunks of rust that we simply lifted up with a putty knife off of the roof of a MN tower that was only 8 years old!

The roofs on the towers get hit the worst it seems. This is for several reasons. One is because the roof will generally get more sunlight than all but the south side of your fertilizer tower. The ultra violet rays can and will deteriorate inferior coatings installed at the factory. Also, the roof being almost flat, will allow fertilizer dust and other chemicals to sit on top, where they can eat away at the paint for days or weeks on end. In the event that it rains hard and washes the top, that’s great as far as getting the chemicals off.

But yet another attack on the paint continues, and that would be the water droplets. Now the water droplets/puddles could generally be considered harmless by themselves. But when the sun rises, and shines through those droplets, it can put a real beating on your capital investment.

Have you ever lit anything on fire with a magnifying glass? That’s right, you go out in bright sunlight, hold the magnifying glass over some leaves or straw, and in a matter of seconds you’ll have a raging fire. The curved glass works in such a way that it can concentrate the suns rays into a very small circle. The power from the suns rays is enough to light just about anything on fire! Water droplets sitting on a steel roof can do the same thing! Except generally they won’t start it on fire, they just burn through the paint day after day until there isn’t any left.

Then the water droplets will continue to eat at the steel until that turns to dust as well! Depending on your environmental conditions, this can happen practically everyday, not even from rain water, but from dew alone. Combine that with the fact that the roof is just about impossible to keep an eye on from the ground, and you could be in for a rude awakening. Don’t wait till its too late!

Protect Your Investment

Minnesota Fertilizer Tower Painting

By the time you notice orange streaks running down the side of your tower, chances are that the roof is losing pieces of flesh the size of Bluegills! This artifact was taken off a blender tower roof less than ten years old. Almost 1/4″ thick!

As you well know, blending towers don’t come cheap! Nor does replacing the roof or wall panels if they get neglected too long. At R&H, we enjoy getting the opportunity to preserve your investment, and save you money. We have decades worth of experience specifically tailored for dealing with these issues. It drives me bonkers every time I see one getting panels replaced! Especially when they could have easily gotten by for a fraction of the price, had they had it re-coated in time.

Matter of fact, a proper maintenance schedule would include maintenance coating BEFORE rust is evident. Generally, this reduces the cost of prep work required before painting, and theoretically you’ll never lose any of the actual metal structure itself. Its kind of like waxing your truck, you let the wax take the beating, and periodically replace it, so that your truck itself doesn’t turn into a big ball of rust.

We have been having fantastic success in keeping Minnesota blending towers rust free, using a combination of multi-part epoxies and urethanes. The epoxies are specifically tailored for keeping the rust at bay, and the urethane topcoat is an ultra high gloss, which works remarkably well for deflecting the suns rays, and making sure the system lasts for a long time! Get ahold of us today! We’ll climb and inspect your tower for free!

Enjoy the snow, Bryce Raisanen