Somewhere I read that “Echant” can be used to ‘age’ the aluminium for my structures. But I cannot find the article now. Anybody have some info on this, please???[?]
Radio Shack and others have circuit board acid etchant that can be used. Put some in a small glass jar and dip the aluminum in it. WEAR GLOVES & EYE PROTECTION!
Nothing will happen for a short while, then bang! all at once it starts to foam and boil. Lift the piece out using tweezers and cancel the acid by dipping it into some clean water. It’s more or less a trial and error, as leaving the materila in too long will eat right through it. Too short a time and the effect is minimal, but you can re-dip them. I’ve seen a suggestion to dip the pieces in a mixture of baking soda(?) to stop the acid working. Maybe someone else can add the info.
As noted, the reaction is failry violent, with splattering and fumes. Do in a well ventilated area - I use my paint spray booth with the fan operating. No use harming yourself for a hobby activity!
Bob Boudreau
COrrect me if I’m wrong here, Mr. Fundy, but isn’t that stuff a caustic solution? If it is, safety glasses and a respirator mask are in order, too.
White vinegar is cheaper and easier to control. It is only 5% acidic but it will do the job as long as there is no varnish protecting the metal. I have used this to “age” some aluminum foil to resemble galvanized roofing.
As an aside, make sure that the container you use to hold the stechant (Ferric Chloride, FeCl(3), nasty stuff) isn’t one you will ever use for anything again, as it stains almost everything it touches a lovely shade of rusty brown. I’ve had pretty good luck with a plastic photo tray, but YMMV.
I do it outside, with plastic tongs, while wearing a full face mask. I’ve been sensatized to some chemicals over the years, and while FeCl3 wasn’t one of them, it’s smell isn’t one I enjoy and the full mask gives me excellent protection from flying droplets.
Bob is right, it works fast, especially when it’s warm. I use a jar of ice water to slow the reaction, and then run it under a hose once the majority of the FeCl3 is washed off. If you don’t wash it completely, there will be a little bit left, and just like acid-core solder on electronics, it will eventually eat away what you started with.
my $0.02
-dave
I used to etch P.C. boards years ago, and I’d like to add a couple more cautions to using etchant. Use a glass container. A Pyrex baking dish would be best. And don’t pour the residue down the drain. It can damage the pipes. Collect it in a tightly sealed container and take it to your local hazardous waste disposal facility. I would also advise wearing rubber gloves when handling etchant, and if you get any on your clothes, the stain won’t come out.
Thank you for your coments. It help a lot. I went ahead and used, outside with plenty of water and precations, and all the precaution were needed indeed! Nasty stuff is right!! I think from now on I will stick to white vinegar and paint.
Thanks!
Lourdes