Messages

Subject:
some critical information missing
Response To:
It's all relative ()

Bill Tindall, E.Tn.
What I have learned in life is to beware of engineers posing as chemists, even chemical engineers.

What was the concentration of the sodium hydroxide? Sodium hydroxide is commonly sold from lab and industrial supply sources as a 50% solution. Household ammonia is typically 3% ammonia in water. The difference in hydroxide concentration between these solutions is about 1000 fold.

If ammonia attacked the carbide binder the solution would become intensely colored.

So, whatever concentration of NaOH was put on a shiny piece of carbide dulled it after some undisclosed amount of time. Roughening to the depth of the wavelength of light will dull a mirror surface. Would this reaction continue over time, or would the reaction products passivate the surface and the reaction stop?

Is this observation relevant to our cleaning and use of a blade with carbide teeth? What does it predict?

I would not suggest soaking a blade in ammonium or sodium hydroxide for a long period of time. I would be more concerned about attacking the tooth weld than premature dulling or whatever was claimed.

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