Does NaOH Corrode Brass and Other Metals?

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SUMMARY

Sodium Hydroxide (NaOH) significantly corrodes brass due to its zinc content, while copper's resistance to NaOH is less clear. The discussion emphasizes the need for alternative materials when using NaOH, suggesting PVC valves as a viable option despite concerns about quality. The user ultimately decided to replace most brass components with nylon, retaining only one part that was uncertain in material composition. Density testing was employed to identify the metal, revealing it was neither copper nor brass, indicating a lighter alloy.

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  • Basic principles of density measurement and material identification
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mrjeffy321
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Without getting into too much detail on what I am building, here is what I am basically asking,
Will Soidum Hydroxide (NaOH) corrode brass?
I am thinking yes. Bras is made up of zinc (which I know NaOH will corrode) and copper (I am not sure about copper).
Basically, I have a value, made mostly from brass, that I want to use to control the flow of something which will be in VERY Close proximity to a concentrated solution of NaOH. The valve probably has some steel in it too I am guessing.

So what metals are out, obviously Aluminum, Zinc, ...?
Are any metals "in"?

I would probably be better going with a PVC valve, right? But I don't think they are as high a quality as the metal ones, plus I want[ed] to connect the value to a brass hose barb adapter to connect to a plastic tube. I guess I could go PVC all the way.

Any thoughts?
 
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OK, what I ended up doing is trading in all my brass parts for plastic (they call it nylon I think), except for 1 part which I looked and looked and couldn’t find a plastic equivalent for, but this one is either copper or brass, so let's hope it can take it.

EDIT:
Do you want to know how much of a nerd I am?
Since it didnt say anywhere whether the metal part I bought was brass or any other metal, and since it looked esspecially shiny and copper like, I decided to test it. So, as all of you know, the most fun way to test what kind of metal something is on a Friday night is of course, find its density.
Not having a very accurate way to measure volume besides water displacement and that fact that theoretically water weighs 1 g/cc, I found the part to have a density of about 5.5 g/cc, and that is rounding up slitly to make up for the inaccurate volume measurement.
I looked up the densities of Copper, Zinc, and Brass,
Cu = 8.92 g/cc
Zn = 7.14 g/cc
Brass = about 8.9 g/cc

So, I found out, assuming my measurements can be taken seriously, that it is made out of none of the above, or atleast is alloyed with a much lighter metal (hopefully now aluminum).
 
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