Ferric Chloride Powder ???  - Page 1
Forum section: electronics / beginners

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 24, 2013, 04:38:12 pm
content: Hello after i saw that is not very convenient to order pcbs premade i decided to etch them with ferric chloride.I found the ferric chloride in a powder and in a liquid form.The thing is that the powder is a lot cheaper but i dont know.1)how to use it2)how to desolve it3)what i should desolve it in ...please help THANK YOU.

author: grumpydoc
author_rank: Super Contributor
timestamp: March 24, 2013, 04:56:37 pm
content: QuoteThe powder is the yellow stuff, right? (there are two forms)QuotePrepare PCB with resist (draw with permanent marker, toner transfer, tape, UV resist - whatever takes your fancy), pour ferric chloride solution into aplasticcontainer, put in PCB, leave until the copper has dissolved where there is no resist, remove, rinse and dry.It will go faster if you warm the solution to 30-40oC and/or agitate the board.QuoteI think it's about 250g of ferric chloride to 1L of waterQuoteWater. Tap is OK, deionised slightly better.

author: IanB
author_rank: Super Contributor
timestamp: March 24, 2013, 05:06:20 pm
content: Before you start you should make sure you have something to store the solution in. Once you have the liquid you can keep it and use it several times before it is exhausted. You will need a plastic bottle with a plastic stopper, and a plastic funnel to help pour the liquid into the bottle. Keep the liquid far away from anything made of metal, and make sure to wear a protective apron/overalls, safety glasses and rubber gloves while handling it. The stuff is nasty and will corrode and stain anything it touches.An important rule: always add the ferric chloride in small amounts to water.Never add water to ferric chloride!Dissolving or diluting ferric chloride produces a lot of heat and there could be steam and fizzing and splattering all over the place.To make a ferric chloride solution for use, you will need a large plastic jug. Place about 250 ml of water into the jug. Measure out about 100 g of ferric chloride powder into a separate dry container. Add this powder slowly to the water in the jug using a plastic spoon, one spoon at a time. Stir to dissolve before adding the next spoonful. Don't leave undissolved powder sitting on the bottom of the jug.When you have finished dissolving the powder, allow the jug to cool down and then carefully pour it into your plastic bottle using the funnel and cap the bottle.To use it for etching, use just as much of the solution as you need to cover the circuit board in your etching tray. You don't need to use all of it at once.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 24, 2013, 05:07:14 pm
content: Quote from: grumpydoc on March 24, 2013, 04:56:37 pmFirst thank youthe powder is the solid form of ferric chloride (little balls ) not the liquid one.Second thanks for the infoalso i have to make a few more questions1 : shall i make small batches and then dispose it or just make a pretty large batch and then store it after every use.2 :shall i dispose it in the sink with a lot of water (not to harm the copper pipes)or is this wrong

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: March 24, 2013, 05:07:20 pm
content: Hello Chris,4 to 1 distilled water to powder ratio, you should probably be aware of the safety issues associated with etching pcb's> wear proper clothes, eye protection, be extremely cautious about getting any of it on your skin and have a well made plastic container with a lid to keep it in.You should take some time and read on the internet, there are also other ways to etch boards with different chemicals:Cupric chloride:http://www.instructables.com/id/PCB-Etching-Solution-Cupric-Chloride/ferric chloride:http://en.wikipedia.org/wiki/Iron(III)_chlorideread #2 in "preparation"Hydrochloric acid is easy to get, but you have to be extremely cautious about handling it, it can cause severe chemical burns.Also you can use Vinegar, salt, and hydrogen peroxide, which makes a fairly weak etchant but with air from a pump you can speed things up a bit.http://hackedgadgets.com/2011/04/11/hydrogen-peroxide-distilled-white-vinegar-and-salt-as-a-pcb-etching-solution/

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 24, 2013, 05:10:48 pm
content: Quote from: IanB on March 24, 2013, 05:06:20 pmThank you for answering my questions but the" DO NOT ADD WATER STRAIGHT TO FERRIC CHLORIDE " made me a bit nervous.Also if i disolve one spoon at a time will the container melt due to the high temperature?

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 24, 2013, 05:13:46 pm
content: And while i was posting this issue another one occured.The Greek store i found has 5 euro shipping fees and a 5 euro fee for the payment (i dont know the word but it means that when the item arrives you pay it also has bank accounts available but i will check this section out late)and if those where not enough for you the ferric chloride balls is out of stock ....what a bummerwhere can i find ferric chloride online at a reasonable price (because ebay is a bit crazy)

author: IanB
author_rank: Super Contributor
timestamp: March 24, 2013, 05:21:58 pm
content: See if you can find ammonium persulfate. It is more pleasant to handle than ferric chloride, and works just as well:For supplies, you might check out not only electronics supply places, but also arts and crafts supply places. Copper etching is used by artists as well as by electronics makers.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 24, 2013, 05:38:21 pm
content: http://www.ebay.com/itm/New-200g-bag-Process-Reagent-Etchant-for-Copper-PCB-Environmentally-Friendly-/290815868467?pt=LH_DefaultDomain_0&hash=item43b5f9fe33The only thing i could find ... does anyone know what is it ?

author: mariush
author_rank: Super Contributor
timestamp: March 24, 2013, 05:44:35 pm
content: Farnell has all kinds of substances :http://uk.farnell.com/ferric-chlorideAlso get the brand name and product code and google it, you'll find plenty of uk and eu stores that stock them.

author: c4757p
author_rank: Super Contributor
timestamp: March 24, 2013, 05:47:21 pm
content: Quote from: IanB on March 24, 2013, 05:21:58 pmSodium persulfate is similar.Quote from: ChrisGreece52 on March 24, 2013, 05:38:21 pmThat? That is industrial sludge that somebody accidentally dropped copper into and discovered that it dissolved. Just a guess. Can't think of any other reason not to label the contents.

author: grumpydoc
author_rank: Super Contributor
timestamp: March 24, 2013, 06:40:47 pm
content: QuoteThat's why I asked whether you had the yellow stuff.That's the hexahydrate, it doesn't get hot when you add it to water - in fact it helps to warm the water before you try to dissolve it. Also you probably won't encounter too much unpleasantness if you add the water to the solid (though it's best to do it the other way round).It's also possible to come across anhydrous ferric chloride (or, perhaps, order it accidentally online) - that's rather nasty stuff. Deliquesces releasing HCL mist** and gets very hot when you dissolve it in water and is generally much more dangerous to have around.** so wikipedia says, I've no reason to doubt it but thankfully I've never tried to handle the stuff myself.Keep the made up solution well away from anything metal but it can be stored and re-used until it doesn't etch any more - you'll notice it taking longer and longer to etc your boards. How long depends on your board design.The used solution needs to be disposed of correctly as it is an environmental hazard.As others have pointed out there are other etchants which have different, perhaps better, properties for home etching.

author: A Hellene
author_rank: Frequent Contributor
timestamp: March 24, 2013, 06:49:24 pm
content: Chris, if you reside in Athens you can find ferric chloride in solid 'peas' form at the down-town industrial chemicals shops, located at Mainandrou St. and Geraniou St. (at the end of Sophocleus St., just before Piraeus Ave.).Meanwhile, you can read what I have written on theuse of ferric chloride(even though the whole thread is worth reading) in another discussions community.-George

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 24, 2013, 07:14:15 pm
content: QuoteThis is typically a dark green/brown powder. Not only is it nasty, when dissolved it won't even etch - you need to do something else to it (I don't recall what) to turn it to a form that works.Incidentally, PCB supplier Mega in the UK have said that they can't get the hexahydrate (yellow) granules any more as the manufacturer has stopped making it, and they can only supply liquid now.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 24, 2013, 07:55:13 pm
content: Quote from: A Hellene on March 24, 2013, 06:49:24 pmThanks George but you make a mistake here being from Greece does not mean that i live in Athensbut thanks for the advice.

author: IanB
author_rank: Super Contributor
timestamp: March 24, 2013, 08:12:38 pm
content: Quote from: mikeselectricstuff on March 24, 2013, 07:14:15 pmI think it will etch, but you don't want to make the solution too concentrated. It needs to be a bit diluted before it will etch well.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 25, 2013, 12:09:33 am
content: Quote from: IanB on March 24, 2013, 08:12:38 pmIt was many years ago when I was at school, but it definitely would not etch - I asked my chemistry teacher about it - don't recall what, but it needed something adding before it looked and acted like normal FeCl etchant.

author: Psi
author_rank: Super Contributor
timestamp: March 25, 2013, 12:44:55 am
content: I would recommend against using Ammonium Persulphate.It only works when it's very hot and doesn't stay hot for long unless you put the container into a large bucket and surround it with boiling water.The heat also tends to melt off thin traces when using the toner transfer method.FeCl or HCL+peroxide work much better.I've never tried Sodium Persulphate, so dunno about that one.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 25, 2013, 12:46:35 am
content: I am not sure what to choose... i would go with ferric but thething its the fumes...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 25, 2013, 12:48:22 am
content: Normal ferric produces negligible fumes at normal working temps (say 50 deg.C) . I've not tried any of the alternatives, but IME the only downside of FeCl is that it stains anything it touches.

author: IanB
author_rank: Super Contributor
timestamp: March 25, 2013, 12:49:37 am
content: Quote from: ChrisGreece52 on March 25, 2013, 12:46:35 amFerric chloride solution doesn't make any fumes, it's quite docile. You just have to be careful about the way it will corrode and stain anything it touches, so you must use only plastic or glass containers. And don't spill it or splash it...

author: Psi
author_rank: Super Contributor
timestamp: March 25, 2013, 06:36:58 am
content: You can microwave FeCl to warm it up as long as you're careful and do it slowly.Don't do it in a sealed container etc..And you shouldn't do it in a microwave used for food.I'm not sure what temp FeCl starts to boil/fume but you really want to avoid that which is why i say to do it slowly.I've warmed it up in a old 600W microwave many times without issue.

author: ftransform
author_rank: Frequent Contributor
timestamp: March 25, 2013, 06:50:05 am
content: I dissolve a 1:2 ratio of ferric chloride to water by mass and use the sponge dabbing method (double gloves, fan, outside), where you dab the PCB with a soft sponge.Takes a bit but you only need a little bit of etchant, no tanks etc (free electrons method)

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 25, 2013, 08:58:21 am
content: Well thank you for your suggestions and sollutions all!!!I loved the moment i read it has no fumes and then the thing that the only danger is that corrodes metals and stains everything.Now as for the microwave thing i am not sure about it becuase i will screw things up if i attempt it.

author: amyk
author_rank: Super Contributor
timestamp: March 25, 2013, 09:45:03 am
content: Quote from: ChrisGreece52 on March 24, 2013, 05:38:21 pmLooks like one of the persulphates as it mentions that oxygen is evolved. Someone who knows Chinese can say more about what the label says.

author: BravoV
author_rank: Super Contributor
timestamp: March 25, 2013, 09:59:46 am
content: Quote from: ChrisGreece52 on March 25, 2013, 12:46:35 amC'mon, people especially hobbyist had been using ferric chloride for many-many years and they (me included) are fine and healthy so far as long you're not too retarded when using it like drink or splashing it like crazy, thats all.Also since you're always whining that you're so poor throughout this forum, then stop being so picky like a rich boy.Just use whatever cheapest stuff that is available and live with it, other wise, just stop playing with electronic.

author: gregariz
author_rank: Frequent Contributor
timestamp: March 25, 2013, 10:07:15 am
content: Quote from: ChrisGreece52 on March 24, 2013, 05:07:14 pmYou could do that but it makes me uncomfortable to throw it into the water system. What I do is throw a box of baking soda into it (slowly, as it will froth) to neutralize it and until it turns to a mostly dry mud. Then I just scoop it out into a bag and throw it in the trash.

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: March 25, 2013, 11:03:18 am
content: vinegar peroxide and salt will etch a board just fine, you probably have all the stuff in your cupboard. get a plastic container drill two small holes in the lid, use a small aquarium pump to supply air to the mixture and if you're concerned about copper pollution put a small ball of aluminum foil in with it<this causes a replacement reaction where the aluminum takes the place of the copper in the solution and makes it pretty harmless afterward.Sometimes you have to improvise (think outside the box)none of the methods will work well if you don't have a good etch resist, make sure whatever you use stays stuck good to the surface of the board and that your board is cleaned well with alcohol or something that will get all of the dirt grease and oxidization off of it.attached is a small board I etched with vinegar, peroxide and salt:

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 25, 2013, 03:54:01 pm
content: Quote from: BravoV on March 25, 2013, 09:59:46 amHey thanks for the info but i am not "picky" i just want to search before i get something that i need so much.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 25, 2013, 03:58:01 pm
content: Quote from: gregariz on March 25, 2013, 10:07:15 amThank you for the info as for the dumping in the water system sentence ... in Greece the pipes lead to biochemical cleaning units that clean the human waste and then dump the clean substances into the ocean and i heard that ferric chloride is not bad for the sea and does not harm the pipes if it is combined with a lot of water.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 25, 2013, 04:00:20 pm
content: Quote from: 4to20Milliamps on March 25, 2013, 11:03:18 amThanks for your advice but where i can find hydrogen peroxide( i may have it already but without knowing it ) (and i would also like to know where it is used for)

author: grumpydoc
author_rank: Super Contributor
timestamp: March 25, 2013, 04:21:26 pm
content: QuoteIt isn't - but copper ions (which your spent etchant will be full of) are toxic to aquatic animals even in small quantities.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 25, 2013, 10:18:53 pm
content: Thank you i had no idea !!!can i spill it to an unused part of the garden we have here?

author: IanB
author_rank: Super Contributor
timestamp: March 25, 2013, 11:03:38 pm
content: Quote from: ChrisGreece52 on March 25, 2013, 04:00:20 pmHydrogen peroxide is used as an antiseptic (from a chemist/pharmacist), as a bleach for hair (chemist/pharmacist/hair salon), and as a water clarifier/disinfectant for pools and spas (from a hardware store/swimming pool supplies).

author: IanB
author_rank: Super Contributor
timestamp: March 25, 2013, 11:10:09 pm
content: Quote from: ChrisGreece52 on March 25, 2013, 10:18:53 pmI think it would be OK to flush small amounts (half a litre or so) down the drain now and then if diluted with lots of water. Waste water treatment plants are quite good at dealing with small amounts of contaminants, given the amount of household cleaning chemicals they have to deal with.

author: Psi
author_rank: Super Contributor
timestamp: March 25, 2013, 11:22:21 pm
content: I used to keep the used FeCl around the house until the next Hazmobile visit and hand it over to them.(In NZ we used to have a few big truck that go around the country every year or so. They setup a drop-off zone for a few days in each city where people can hand in hazardous chemicals)Sadly i think they have stopped doing that.The fact that copper is so toxic to aquatic animals and no longer having the Hazmobile to dispose of it is why i moved to HCL+Peroxide for etchingSince you don't ever need to throw it out you can just keep refreshing the solution.Also the solution is clear, so its easier to see when the pcb is done over FeCl

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 26, 2013, 05:56:31 am
content: I am not sure about that delema both are good for etching the quality looks the same (both comments are good) but ferric chloride is very hard to dispose...is hydrogen peroxide easy to dispose?

author: Psi
author_rank: Super Contributor
timestamp: March 26, 2013, 06:08:43 am
content: I'm not sure about disposing of a peroxide+hcl etch solution.It's still going to be full of copper you etched off, so tipping it down the drain is probably just as bad as FeCl.But at least with hcl+peroxide you can 'refresh' the solution and keep using it again and again by topping up the level of chemicals or bubbling air through it to regenerate the cupric chloride in solution.You never need to throw it out.So its much better in that respect

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 26, 2013, 12:30:12 pm
content: Thank you but i still have a question.... how do you "refresh" it ?i mean you just add more chemicals or something ?

author: Psi
author_rank: Super Contributor
timestamp: March 26, 2013, 12:35:54 pm
content: You can bubble air through it using a fish tank air pump or add a little more peroxide.(if you use a fish tank pump don't use it for fish tanks again afterwards)Just google for peroxide HCL etching, there are lots of guides.etchttp://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/One note: If you can get hold of peroxide at a higher percentage eg 30-50% you end up with a better solution.Your typical pharmacy/drugstore peroxide is only 3 or 6% so you're diluting the etchant with water every time you add it.Be careful though, hydrogen peroxide is extremely reactive at high concentrations.Drug store 6% works fine though, so if you want to play it safe just use that.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: March 26, 2013, 04:12:07 pm
content: Thank you so if i MUST dispose it (ill probably refresh it everytime but who knows) what can i do ?