Monday, October 10, 2011

How to decontaminate stainless steel of radioactive contamination?

Question: 
Does Alconox decontaminate stainless steel from radioactive contamination?


Answer:

Yes, Alconox powder can decontaminate stainless steel of radioactive contamination. The phosphates and chelating agents combined with the wetting agents in Alconox are known to be effective at decontamination.  

We recommend use of a warm (if practical, otherwise ambient temperature solutions, it just takes longer) 1% (10 g/L or 1.25 oz/gal) solution of Alconox detergent in water for manual or soak cleaning. Do not use any kind of pressure spray or automated cleaning equipment as Alconox is a high foamer.  

Note that Alconox will bind with radioisotopes and will inhibit separation and waste treatment of the spent cleaning solutions by ion exchange columns.  It is better to treat spent cleaning solutions by evaporation than by ion exchange.  Sometimes it is necessary to use an anti-foamer in the evaporator depending on the evaporator design and the volume of solution being treated with what other types of waste streams if any.


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For a free sample, visit: http://www.alconox.com/sample15.html

How to degrease aluminum?

Question:
What is the best cleaner to use when degreasing aluminum?


Answer:

First, the word "degreasing" is a technical term used by many metal manufacturers that means removing oil (with or w/o grime) on the surface of the metal. 

It comes from the historical use of a vapor degreaser using freon, where people dipped dirty metal parts in to the freon vapor, the vapor condensed on the part and dripped off while solvating off the oil, then more vapor formed to rinse. You did not have to rinse with this type of cleaner. Freon is ozone depleting so it is not commonly used any more, but because of this history the industries that used to use them do not like to rinse. 

Degreasers can also mean heavy duty alkaline cleaners, typically with corrosion inhibitors - sometimes these industries never even rinse these because they are just not that critical an application (removing grease from engine parts in a railroad engine that is going to be reassembled and have fresh grease put on it for example).

WHEN PASSIVE OXIDE LAYER BROKEN 
If the bare aluminum has been recently cut, abraided, polished, turned or drilled, then the passive oxide layer will have been broken and if it has not had time to reform in air (takes 15 min or so) or if it has an oily coating that interferes with air getting to the surface, then the aluminum is not passivated.  Unpassivated aluminum will be attacked by an alkaline cleaner, even ones with mild pH or silicate corrosion inhibitors.  For unpassivated aluminum we only recommend using Citranox or Citrajet for degreasing

If Citranox or Citrajet is not  rinsed off an aluminum salt will form on the surface.  For most applications this will not harm the aluminum, and will only cause slight brown discoloration mostly visible by magnified inspection and barely detectable to the naked eye as a golden brown discoloration. 

It is always recommended to rinse, and the first rinse water following the Citranox or Citrajet cleaning should be with cold tap water NOT DI.  DI water is more ion hungry, will expose more sites to undesirable oxidation from the dissolved  oxygen, and will cause discoloration of the unpassivated surface.  If tap water is not available as first rinse, then wait 15 minutes before rinsing in DI at the expense of any possible problems with dried on and/or redeposited residues from the cleaner. 

In heavy duty degreasing, people may be fine simply wipe rinisng or blowing off the parts and can probably live with any trace hazy discoloration.  For more critical cleaning where the term degreasing is less likley to be used, you absolutely have to rinse thoroughly. 

WHEN PASSIVE OXIDE LAYER PRESENT 
If the bare aluminum (or metal) has the protective oxide layer present and is in a passive state, then we recommend an alkaline cleaner: either mild pH or with silicate corrosion inhibitors. 

Note that anodized aluminum is an aluminum that has been electrically treated to form a stronger oxide or other coating that you typically would safely recommend an alkaline cleaner for, unless there has been cutting or anything that has gone thru the anodizing in which case you are back to all the concerns about bare aluminum.   Typically people do not cut or abraid anodized aluminum, they would do the anodizing after all the cutting or drilling.



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For a free sample, visit: http://www.alconox.com/sample15.html

How to clean installed solar panels using minimum amounts of water?

Question:

How to clean installed solar panels using minimum amounts of water?

Answer:

For field cleaning of solar modules, I recommend using Liquinox detergent. (See the MSDS and technical bulletin links below). This is a concentrate that would be used at a 1% solution (1.25 oz/gal, or 10 mL/L).



Liquinox is not harmful to discharge onto the ground in an agricultural setting nor will it attack glass or aluminum substrates. I would recommend developing a cleaning procedure that allows you to spray on the 1% Liquinox solution using irrigation water (possibly use a garden sprayer or backpack sprayer), then:
  • allow the sprayed on solution to sit for as long as is practical without excessive evaporation, 
  • do some scrubbing with a light plastic brush to get any really tough spots loosened up, 
  • rinse thoroughly with irrigation water,
  • if practical, do a final rinse and finally squeegee dry. 
Water spots occur when tap water or dirty water evaporates and deposits contaminants on the surface; using a squeegee removes the water before it can evaporate and make spots. Whoever is doing the cleaning needs to understand this and learn to work in a way that minimizes evaporation, particularly on the final rinse. 

For the Liquinox MSDS, see: http://www.alconox.com/static/msds/msds_liquinox.asp 
For the Liquinox Technical Bulletin, see: http://www.alconox.com/downloads/pdf/techbull_alconox.pdf


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For a free sample, visit: http://www.alconox.com/sample15.html

How to eliminate beading when cleaning pipettes?

Question: 

We are doing some experiments to quantify the amount of liquid residue on pipette walls before/ after cleaning. In practise, this would relate the accuracy of the pipette to its cleanliness. 

Could you inform us if the use of Alconox affects the amount of beading (of distilled water) on the walls of a brush cleaned and rinsed pipette, compared with the use of common dishwashing liquid? 

Answer:
Proper cleaning of a pipette will result in proper functioning of the pipette: the designed amount of fluid being measured will be correct if the pipette is clean and the surface energy of the glass in not altered by any residues that would change the shape of the beading of the fluid being measured.  Typically pipettes are calibrated for water, but you can get specialty pipettes designed for other fluids, such as milk. 

Alconox is free rinsing, which means it does not contain any fragrances, dyes, cationic surfactants, fluorescent whitening agents, corrosion inhibitors, skin emollients or other ingredients that are designed to leave deposits on the substrate being cleaned.  If you rinse thoroughly, you will not have any Alconox residues to cause a change in surface energy of the pipette. 

A common dishwashing liquid might have a risk of depositing one of these non-free-rinsing ingredients that would typically be hydrophobic and would alter the surface energy of the glass/solution interface and change the accuracy of the pipette.  Smaller pipettes have a chance of residues impacting the pipette’s functioning.


For an Alconox MSDS and technical bulletin, see: http://www.alconox.com/static/msds/msds_alconox.asp 

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For a free sample, visit: http://www.alconox.com/sample15.html