What's The Best Coating For Protecting Vacuum Tanks From Corrosion?

What’s the best coating for protecting the interior of a steel vacuum tank from the daily onslaught of corrosive loads?

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Question

I’ve been cleaning the inside of my tank. The protective coating did not adhere everywhere. The unknown coating is a red primer and a thick black coating. Any guesses? The tank’s 5/16-inch walls should be a higher carbon steel. I’d like to fill pits with weld and would like a recommendation on what wire would be best.

Answers

I use foundation tar. It’s cheap and easy to find, and works best when the tank is dry. There is also a wet and dry tar that is thicker, if you can’t get the tank dry. I bought a used tank that was coated with tar on the inside and it made it 30 years.

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How often do you scrape out your tanks? And where do you get rid of the sediment? 

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I think the original paint was epoxy, but I’m not sure. I used two coats of Master Series silver rust sealer and two coats of any enamel lying around the shop. The inside of the tank is multiple colors using up the old paint.

I used a 2-inch water pump to wash out the grit and work on it. The county asked me what will I do with the grit. I said I’ll put the grit where you tell me to. I’m restoring this old truck and haven’t used it yet. I’m assuming the county will tell me what to do with the grit when I start running the truck.

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I’ve heard over the years that tar is the way to go. I have an older tank that is still solid I want to coat shortly also. I’m considering tar. Now is this plain old heat-then-paint tar, or are you talking a roofing tar that doesn’t need to be heated? What about the fumes in a confined space?

In an old, rusty but solid tank, how do you suggest prepping the inner surface? Scraper, grinding wire wheel, sand blast? Something else?

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I use a fresh air respirator anytime I’m in the tank. Anything will probably extend tank life, but roofing supply houses sell a cold-process adhesive for “built up roof” installation, or BUR as they call it. I’ve never used it in a tank, but I’ve used it on my BUR roof and like it. It doesn’t get as hard as a rock, which is why I think it would be better than tar.

A needle scaler works well on rust cleanup. No doubt sandblasting would be the best, and some blasting places blast inside tanks.

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Just curious to know if anyone has tried this method? On my inspection cap on top, I have used Kilz basement paint. I used the sealer first. It has worked fairly well. I hear some people will climb inside and spray the tank with bedliner. Anyone ever had this done, and how long does it last? 

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[A] company that’s been building steel tanks for many years uses some kind of coating from Sherwin-Williams that’s applied to the bottom of ships. An idea is to find a business that does spray-in bedliner and get them to fix you up. Some of that stuff is better than others, so check up on them. I’ve seen that stuff used for a lot of things and the good stuff is pretty tough stuff.



Discussion

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