modified 9 years ago

What Etching Solution Do You Use

00:26:44

I was wondering what etching solution could be made in home conditions and how useful is it? I usually find weak solutions very slow and unsatisfactory and the very strong solutions like nitric acid very aggressive. I found that you can make a simple solution by concentrating sulfuric acid from a car battery by boiling the water off and then diluting it with hydrogen peroxide. Haven't tried it yet though. What solution do you use? 

published 9 years ago

Robert_Kidd

9 years ago

I would advise against playing with sulphuric acid and heating it is asking for trouble. I would advise you don't do this. Traditionally ferric chloride is used with 1% hydrochloric acid added. With any of these substances protect yourself well, eye protection and gloves are a must.

WTFCircuit

9 years ago

Nitric acid is one of the few acids that can dissolve copper, but it is indeed quite violent and it ganerates a ton of nitrogen dioxide, a toxic dense dark red gas. I prefer the iron cloride metod, because it can be stored indefinetly and it can be relatively easy to recover. The peroxide based solution don't last very long because the peroxide decay into water and oxigen. Also the sulfuric acid - hydrogen peroxide one is extremely dangerous due to the formation of peroxymonosulfuric acid, one of the stronghest oxidiser we know, expecially for organic materials. There are then other clorine and hypoclorite salts methods but those are also not very stable.

thebugger

9 years ago

I'm not looking for stability. Most solutions have a low shelf life when activated, a month or so. I'm looking for just the right strength. Strong acids are mostly out of the picture. I've had some experience with nitric acid and I almost always missed the moment and got myself a fully disolved PCB. I'm thinking more of peroxide solutions or FeCl3, but I need something I can make at home, because access to acids is hard where I live.

Robert_Kidd

9 years ago

I've used ferric chloride for many years. It keeps well in a plastic container. It will stain anything it touches, fingers, clothes etc.

Robert_Kidd

9 years ago

If you agitate the PCB you can watch it progressing quite nicely and it doesn't take too long.

thebugger

9 years ago

Yeah but I can't make FerroChloride in home conditions. I can make most of the peroxide solutions. Got any experience with them?

Robert_Kidd

9 years ago

I see it's available from Amazon but I don't know if you can get it in your country.

Robert_Kidd

9 years ago

Only other one I've used is sodium persulfate but only on one occasion. It worked ok but can't offer you much advice.

Robert_Kidd

9 years ago

Why can't you make FC at home?

thebugger

9 years ago

How can I make FC at home. BTW what's your opinion on Sodium Persulfate. I think I can get my hands on some

Robert_Kidd

9 years ago

I can buy ferric chloride in ready to use liquid or in dry form ( powder or balls) which you just mix with water. Add 1% hydrochloride acid if you want to speed etching process. SP worked ok but I can't give much advice as only used once.

Robert_Kidd

9 years ago

From memory, the next time I wanted to use it, it was inactive.

thebugger

9 years ago

Yeah it has a short shelf life after which it becomes inactive. That's the problem with peroxide solutions, they are unstable. The best is either Ferric Chloride or Nitric Acid, but both are hard to make in a home environment.

checker

9 years ago

http://m.youtube.com/watch?v=43Xsh9J7S-g

checker

9 years ago

But... I would just buy the FeCl3 balls, powder or liquid, safer faster easier

Robert_Kidd

9 years ago

Still not sure why you think it's hard to make in a home environment? Just pour it (or mix it) in a plastic box with lid - lunch box or similar.

thebugger

9 years ago

Access to acids is somewhat restricted in Bulgaria. Only way is to make some yourself. Basically the only way I can make some homemade nitric acid is to make some sulfuric acid by electrolysis of copper sulfate solution, then concentrate the solution, then make hydrochloric acid out of it with table salt and then convert the hydrochloric acid to nitric acid with some sort of nitric salt. Good news Is both copper sulfate, and nitric salt are very abundant where I live, and I can probably get large quantities over a small price range. Bad news is that I have to synthesise every possible acid known to man to get some nitric acid.

thebugger

9 years ago

And Personally I wasn't very good at chemistry. I might actually die from creating 3 separate acids.

WTFCircuit

9 years ago

I think the ferric cloride should be even easier to produce. Just heat up a solution of hydrocloric acid and iron wool, with something to recondense any acid and water that can escape. Be careful, this reaction produce large amount of hydrogen which is explosive in almost any concentration in air. Anyway in bulgaria you don't find any muriatic acid, which is just 35% hydrocloric acid, used to clean porcelain and similar?

thebugger

9 years ago

We used to have something called Kislol, whicb was the equivalent of Muriatic Acid, but nowadays all detergent are some fancy chemicals and almost no hard chemicals

thebugger

9 years ago

Plus Once I have the Hydrochloric Acid it's veeeery easy to convert it to Nitric Acid, you just need some copper and ammonium nitrate, which is a fertilizer, my dad's into agriculture and buys a hundred tons a year

Robert_Kidd

9 years ago

So you wouldn't be able to buy Ferric Chloride off Ebay in Bulgaria?

Robert_Kidd

9 years ago

Excuse my ignorance on your country.

thebugger

9 years ago

Yeah and I have to wait for a month for it to arrive.

Robert_Kidd

9 years ago

Good God!

Robert_Kidd

9 years ago

And if I were to mail a parcel to you would that take a month too?

WTFCircuit

9 years ago

Do you have bleach or something? Because I remember some metodes based on it, but those also have to be made in loco, otherwise they will lose strenght overtime

thebugger

9 years ago

Yes overseas mail always takes time :/ I think I can get mt hands on some sodium persulfate. I'll see if it does me good, if not imma make me some nitric acid

Robert_Kidd

9 years ago

Interesting. In theory it takes 3 to 5 days to send a parcel from the UK to Bulgaria according to Royal Mail website. I wonder if it gets help up in customs your end. Anyway you seem to had decided on a way forward :-)

thebugger

9 years ago

Ah Britain is something else. I thought you lived in America due to the good english, and from USA it's a lot of time. Come to think about it, Americans have worse English than the nomads, can't tell what threw me. Intercontinental parcels take up to 2 weeks tops (during holidays). Anyway thanks, I'll try first with the Sodium Persulfate, cuz I can find It cheaply if I have trouble I'll revisit the subject.

Robert_Kidd

9 years ago

And you? Are you a Bulgarian with very good English?

Robert_Kidd

9 years ago

I have such good English because I'm NOT American lol. But I have nothing against them.

thebugger

9 years ago

Exactly, Americans have the worst english from all the nations who speak the language. Yeah I'm bulgarian, but English is like my second mother's tongue

kiani

7 years ago

In fact Americans English is more correct than the English English, whether I like them or not.

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