I really need to etch some very small brass or stainless steel parts, but I don’t have any photo-etching gear. Do we have the correct gear? I would love either some training if we have the stuff, or if someone has photo-etching gear I would be glad to pay for you to etch something. I could provide artwork and the metal.
How strange that you mention this today. A teacher dropped off some etching media today and asked me if I could use it (for my classroom). I texted @AnneGullett and we are going to meet and see if it can make it work with whatever I have in my classroom. I etched when I took metals in college and loved it. I would love to get it setup at the space. I will talk it over with Anne and see what all it needs to get setup (from what I remember it was very minimal) my concern is disposal of used etching fluids.
I will keep you posted.
I know @Haley_Moore taught a class on it as well - It was not an acid from what I remember - would you be interested in teaching the class again?
The two chemicals used are typically Ferric Chloride and Sodium Hydroxide. Interestingly enough, sodium hydroxide is one of the two chemicals that can be used to neutralize the ferric chloride for disposal.
We are exploring electro etching…it doesn’t require toxic chemicals like Ferric Chloride. I know disposal of the water after is still an issue because of the metal, so we may need to etch somewhere other than Makerspace.
Please reply if you are interested and we’ll set a date to meet and get this going. I know Patrick and Kate were very interested in this at the J/SM committee meeting :).
Speculating, but if you take all of the “waste” material home it isn’t an issue since DMS doesn’t have to dispose of it. Oil and coolant changes require the individual to take it with them as we don’t dispose of it.
I was thinking along the same lines. If etching were only allowed during sanctioned “classes” and the class fee covered proper disposal and the “instructor” or some other class member took the materials away for disposal … then I would guess it would be permissible.
True…dumping acid down the drain is rarely a good idea. My understanding though is the dissolved copper is highly toxic to the aquatic wildlife that ultimately end up swimming in the stuff dumped down the drain.
I really like using CuCl. There is a good explanation of how to get started on this Instructable (view at your own risk; lots of marketing ahead). I have some and could share it with you if you get the right plastic container for acid. I forget the plastic type but can look when I get home. The beauty of this method is that you never throw it out. You can regenerate the etchant by bubbling air through the solution with a fish tank pump; it changes colors so you know when you are done. You only need muriatic acid (a.k.a. hydrochloric acid, HCl, or pool acid, I have some of that too for my pool that I could share), hydrogen peroxide, and copper. I choose to dissolve copper wire to get started because I don’t etch that many boards but you can also just start etching boards to create the etchant. The only downside is that you really want a fume hood when “regenerating”. It takes hours and produces some fumes. Regeneration is only needed after quite a few boards. The last trait of this method is that over time, as copper is dissolved, the solution needs to be diluted with more HCl and water. Good news is it is like a friendship cake; easy to divide the solution and share. Maybe a partnership with the Science Committee would make sense if others want to use this method.