Dilutions of amonia and oxide hydrogen peroxide for fungus cleaning?

[Neofito]

so I need to clean some fungus, everybody points to this and say "half-half" without saying exactly the original dilution of each liqui. But there are a lot of comercial amonia dilutions. Some are <5%, other 10% and 25%. Hydrogen peroxide is usually 3%.

So which one do you use?

 

[Kino]

Household ammonia in the US is 5 to 10 percent; that's what i use.

25% might be a bit much...

 

[Anon Ymous]

25% ammonia definitely reeks. Handling it can be an issue, especially when it's warm.

 

[Flighter]

From what I've seen on the web the 50/50 ammonia hyrogen peroxide mixture (APM) solution for chemical cleaning was originally developed by Werner Kern at RCA in the mid-1960s, for application to the cleaning of polished silicon wafers prior to semiconductor fabrication, where APM was known as RCA's "Standard Clean" step 1, or SC-1 which also became known as RCA-1 after it was more widely adopted across the industry. RCA-1 specifies 1-part each of industrial strength ammonia and peroxide (27% and 30%, respectively) diluted into 5 parts de-ionized water, effectively reducing the concentrations to 11% or 12% (i.e., comparable to the concentrations of household products). The RCA-1 recipe is 5 parts of water, 1 part 27% ammonia and 1 part 30% hydrogen peroxide. I would avoid heating the mix as far as cleaning lenses goes.

The peroxide I got off Ebay is 12% and the ammonia 34% and I use 3 lots of peroxide to 1 of ammonia and then add 4 lots of water so is not the same as above but works for me.

I've seen warnings against using ammonia alone due to its high pH and the risk of etching glass but mixed with peroxide it should reduce the alkalinity. Warning: I'm not a chemist or a deep thinker so no guarantees.

I've also seen warnings against soaking cemented elements for any length of time and instead the advice is to wipe the surfaces (gently) using cotton buds.

 

[Nicholas Lindan]

Ammonia & H202 is known as 'Base (alkaline) piranha' solution. Piranha is usually made with sulfuric acid.

Piranha solution - Wikipedia

en.wikipedia.org

 

[Flighter]

Ammonia & H202 is known as 'Base (alkaline) piranha' solution. Piranha is usually made with sulfuric acid.

So don't put your fingers in it!

 

[Neofito]

From what I've seen on the web the 50/50 ammonia hyrogen peroxide mixture (APM) solution for chemical cleaning was originally developed by Werner Kern at RCA in the mid-1960s, for application to the cleaning of polished silicon wafers prior to semiconductor fabrication, where APM was known as RCA's "Standard Clean" step 1, or SC-1 which also became known as RCA-1 after it was more widely adopted across the industry. RCA-1 specifies 1-part each of industrial strength ammonia and peroxide (27% and 30%, respectively) diluted into 5 parts de-ionized water, effectively reducing the concentrations to 11% or 12% (i.e., comparable to the concentrations of household products). The RCA-1 recipe is 5 parts of water, 1 part 27% ammonia and 1 part 30% hydrogen peroxide. I would avoid heating the mix as far as cleaning lenses goes.

The peroxide I got off Ebay is 12% and the ammonia 34% and I use 3 lots of peroxide to 1 of ammonia and then add 4 lots of water so is not the same as above but works for me.

I've seen warnings against using ammonia alone due to its high pH and the risk of etching glass but mixed with peroxide it should reduce the alkalinity. Warning: I'm not a chemist or a deep thinker so no guarantees.

I've also seen warnings against soaking cemented elements for any length of time and instead the advice is to wipe the surfaces (gently) using cotton buds.

ok great, then is actually close to one part of hydrogen peroxide per amonia, plus the water which I didnt know how many parts. Thank you for the explanation! people tend to just say "one part of the amonia i bought on wallmart plus one part of the hydrogen peroxide" and thaaat can be literally infinite combinations and ratios of the two chemicals.

 

[tokam]

I've had success in the past just using hydrogen peroxide at 3%. Place a piece of clean cloth in a shallow dish and fill to about 2 cm deep. Soak the lens element in the hydrogen peroxide for a couple of minutes, take it out and wipe and inspect results. Repeat if necessary. Hydrogen peroxide at 3% is safe to handle with bare hands as it can be used to sterilise cuts and wounds etc. Best to start off with the milder attempts at cleaning before introducing higher concentrations and/or ammonia.