spuffock Ferric chloride user, how do you get the rust stains off everything? If the answer is hydrochloric acid, where do you get it from? Anyone know where ammonium persulphate can be obtained? HandyMan Quote: Ferric chloride user, how do you get the rust stains off everything? I use Ferric Chloride and don't have rust stains on anything except the tub I use for etching and the old measuring jug I use to pour the solution back into its bottle. Quote: If the answer is hydrochloric acid, where do you get it from? Well, when I lived in Spain, every supermarket stocked it for cleaning purposes, cos they don't see the need to mollycoddle their population, afraid they're so dumb they'll hurt themselves with something as dangerous as a concentrated acid... but here in the UK, we are too dumb to be allowed to buy such a thing as hydrochloric acid, so I can't help with where to obtain in from in concentrated form. However, there is a kitchen cleaning spray known as Cillit Bang which claims to remove limescale very quickly. I guessed it may use very weak hydrochloric acid in it to do the job, so I mixed some with Hydrogen Peroxide and stuck some copper-clad board in it overnight. In the morning, the copper was gone, so it looks like it does contain HCl. Anyway, a search on Google brings up a solution which claims to be purely for the removal of Ferric Chloride stains... http://www.electronelec.co.uk/stain_remover.htm which uses Oxalic Acid. Quote: Anyone know where ammonium persulphate cn be obtained? Depends which country your in? I don't want to use the stuff because it apparently has a short shelf-life, and is slower working than Ferric. Screech Melbourne Australia Russlk wrote: Thanks for the reply, yes, no holes any time. The printer problem is the same with me, I had not figured out how to make it work. I have been in contact with Eagle email help, I will ask about the pad holes. Russ There is a forum on Eagles web site that may help you. I have used the Free eagle versions 4.11 and 4.13, but never had problems printing the holes. SeeTheHoles.gif Russlk I got the answer to pad holes: I have to set the display mode to "real". Why anyone would want it un-real is beyond me. jbeng spuffock wrote: If the answer is hydrochloric acid, where do you get it from? Handyman wrote: ... so I can't help with where to obtain in from in concentrated form Hydrochloric acid is also known as muriatic acid. It's used to [thoroughly] clean masonry, concrete etc. You might check at a local hardware store or building supply center (your location isn't listed though). JB pike Sydney, Australia pool acid is approx. 50/50 water and hydrochloric acid. Nice and cheap as well. But try to get the strongest one you can get. 50/50 will eat copper easy no problem, may even over etch. DigiTan HandyMan, that was the best PCB walkthrough I've ever seen! Do you other tutorials like this on the web? Cool pike so umm Handyman what is the key ingrediant in this "gentle developer" if you wouldn't mind telling?? I know it's carbonate based but carbonate what?? Phasor evandude wrote: check out my website, I have a tutorial for etching boards from start to finish using toner transfer. http://eegeek.net/electronics/tutorials/tonertransferpcbtutorial.htm Having just acquired myself a laser printer (for nothing! someone threw it out on the street and it works perfect!) and some photo paper, I've just tried your method and it works a charm! Previously I was using PnP - Results were alright, but the stuff is horridly expensive! I have definitely been converted.. Very Happy I added one slight modification to your method - to cool the board, I threw it in the freezer for about 3 minutes. PS for anyone who is interested, the paper I used was Kodak "Everyday Picture Paper for inkjet prints" (the glossy version)