Clean a stainless tank?

[Z/MAN]

I was at the scrap yard today and spotted a huge pile of stainless tanks. There are various sizes and they appear to be 150 to 300 gallon tanks. I'm guessing they had some sort of chemical in them.:( Even though they are stainless there is no way to properly sterilize them is there? These would be perfect sap tanks if there was a way to be sure they were safe. Any ideas?
Paul

[DrTimPerkins]

I was at the scrap yard today and spotted a huge pile of stainless tanks. There are various sizes and they appear to be 150 to 300 gallon tanks. I'm guessing they had some sort of chemical in them.:( Even though they are stainless there is no way to properly sterilize them is there? These would be perfect sap tanks if there was a way to be sure they were safe. Any ideas?
Paul

Can you find out what was previously stored in them?

[OneLegJohn]

Yes,you can clean most stainless to a food grade surface. Trying to clean some polymers from the tank would not be worth the trouble. The previous contaminant would likely need to be nonhazardous and water soluble. What ever contamination you clean from the tank would be your limiting factor and exposure. It isn't so much getting it clean, its proper disposal of waste generated.

That being said, I have a customer that pickles and passivates stainless tanks for large food/beverage plants. Think vats used in breweries or ketchup production. They "rejuvenate" them as tomato paste and wort are very corrosive, even to stainless. The chemicals used to clean and "re-shine" stainless are nasty and essentially remove part of the alloy. Most industrial pickling acids for Stainless contain Hydroflouric and Nitric acid. The key is the process. If the tanks you speak of contained hydrocardons, you must first use an alkaline cleaner (pH 14). Heat and agitate to remove grease or oily residues. Next, you will need to remove the cleaner and follow with a rinse. Next comes the pickling with an acid (pH<1). It is critical to remove the grease in step one because acids work on the substrate and need a clean surface to work properly. Acids do not have cleaning power to dissovle or remove grease. Heat and agitation are a way to improve efficacy of the chemistry. Time is also a factor in performance. After that, remove acid and follow with a rinse. I recommend an extra rinse until conductivity of rinse water in the tank is equal to the water being used.

So yes, it is possible, however the chemistries needed will have to be treated in an appropriate manner designated by local regulations. Before a project like this is done, the time/cost factor needs to be considered.

[w9dwg]

All quality stainless can be cleaned for food grade use. For an example my neighbor hauls gasoline or diesel. Then he sanitizes the tank and in the same tank he hauls cranberry and cherry juice for Orcean Spray.

[Maplewalnut]

All quality stainless can be cleaned for food grade use. For an example my neighbor hauls gasoline or diesel. Then he sanitizes the tank and in the same tank he hauls cranberry and cherry juice for Orcean Spray.


Note to self....do not buy Ocean spray

[tuckermtn]

I had the same though...I'll pass on the Ocean Spray...

while I'm sure it can be done, I'm not comfortable taking that type of chance- even if its stainless, if it has had fuel or some sort of chemical/cleaner in it, its not touching my sap...

[3rdgen.maple]

I can get my hands on about 6 stainless steel tanks in sizes from 100 to 500 gallons for free. Problem being they had jet fuel in them. Maybe the ocean spray guy would like them cause I sure don't. I am glad I do not own stock in that company. Which is a perfect example of how easy it is to get a bad reputation and give our industry a bad name. One guy mentions hauling fuel then cleaning and hauls juice for ocean spray and in less than 4 hours they lost 4 customers. Please be careful in what is used we do not need any bad press time.

[NH Maplemaker]

And the USDA is looking at us!!! If this is ture, I think they are missing the boat on this one! Jim L.

PS Make it 5 coustomers!!

[PerryW]

Maybe that's why I don't like the taste of cranberry juice (unless it has vodka in it).

[Haynes Forest Products]

Diesel fuel kills worms:o Taste goes away after a few days:)

[Z/MAN]

I was at the scrap yard today and spotted a huge pile of stainless tanks. There are various sizes and they appear to be 150 to 300 gallon tanks. I'm guessing they had some sort of chemical in them.:( Even though they are stainless there is no way to properly sterilize them is there? These would be perfect sap tanks if there was a way to be sure they were safe. Any ideas?
Paul

I rechecked these tanks out and found they did have some "BAD ***" chemicals in them.:cry: I will leave them for scrap.
Paul

[Maplewalnut]

Paul-your missing the boat. Buy them and sell them to ocean spray for double the price you paid.

[Haynes Forest Products]

What about the semi trailers they haul garbage in and then clean for food transport

[Maplewalnut]

What about the semi trailers they haul garbage in and then clean for food transport

Little different when its a direct contact surface of a carcinogen