Dauvit-- I have nitric acid that is 74% (as stated by the Lab).
What ratio to water would I used to dilute it for etching silver
or copper? It’s been a LONG time since I did any etching. .Del
It depends on what you are wanting to do. A good bet is to mix it
to between 12 and 15% for a slow and accurate etch with minimal
underbite, but you can mix it up to 25% for a faster, less accurate
To calculate the desired strength, work out the volume you need to
produce (say 100ml) and the strength you require (say 12ml): in
this 100ml, there needs to be 12% pure acid, or 12ml. How much 74%
acid gives 12ml of pure acid? Divide 12 by 0.74 and you get 16.21.
OK. Therefore you need to use 16.21ml of 74% acid in (100-16.21)
83.79ml of water to create 12% acid.
Sorry if this seems very complicated: I know how to do it, but
can’t work it out as a formula (maths was never one of my
strengths). The above works if you substitute the figures you
actually need, for example 250 ml of 18% acid.
All the best,