Hi all. Just tried etching with Muriatic Acid and Hydrogen Peroxide using a 1 to 1 ratio and its taking forever. Much longer than Ferric Chloride. Is there any way to speed up the process? Would heating it up a bit first help?
Some details that might help. The copper clad is 1 oz. Its been in there for over 30 minutes and looks like its about 50% finished. Is this normal?
It depends on the strength of the hydrogen peroxide, usually it's only 3-5%. I get 30% from my pharmacist, but it's very dangerous stuff.
Here's the link that got me started:
http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/ (http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/)
Constant agitation really helps, but watch out for the fumes and splashes on your hands, or worse, in your eyes.
I use a 2 part h202 to one part acid. And yes, heating the solution helps. I use a warm water bowl which I carefully float the etching bowl into.
Are you sure you have 1oz copper? A 1:1 ratio should etch a few boards between 5 and 10 minutes.
Check if your H2O2 is still ok! ( put in a wound and see if still bubbling ;) )
You can also try to add a bit more of h2O2 to your etching solution!
Using a higher concentraion of peroxide is dangerous and you have to be very carefull!
Happy etching
Quote from: madbean on December 04, 2013, 01:00:32 PM
Are you sure you have 1oz copper? A 1:1 ratio should etch a few boards between 5 and 10 minutes.
It is 1 ounce for sure. Last night was a bit cold and I was out in the garage. I'll try warming it up first and see if that helps.
I was concerned about it sitting to long and etching into the traces at spots but it turned out fine, so I guess it's no big deal.
I've had this same problem.
My theory is that some of the newer "safer" muratic acid that they sell at the big box stores do not work as well. Also some hydrogen peroxides contain phosphoric acid. Not sure if that matters either.
But the mix that doesn't work well on copper clad can pretty much disintegrate an aluminum enclosure in a few minutes...
I'm definitely not a chemist but I think some of the inert ingredients in some of the products cause the solution to not work as well on copper.
Quote from: gtr2 on December 04, 2013, 10:23:39 PM
I've had this same problem.
My theory is that some of the newer "safer" muratic acid that they sell at the big box stores do not work as well. Also some hydrogen peroxides contain phosphoric acid. Not sure if that matters either.
But the mix that doesn't work well on copper clad can pretty much disintegrate an aluminum enclosure in a few minutes...
I'm definitely not a chemist but I think some of the inert ingredients in some of the products cause the solution to not work as well on copper.
I did use the safer muriatic acid and was wondering if that had anything to do with it.
I heard about this combination and how quick it was, couldn't wait to try it.
I went through this same process as you, carefully measuring quantities, getting the right concentration of H2O2, etc.
Took absolute ages. Then I found a webpage (unfortunately gone) about a guy who built his own 737 cockpit to fly in conjunction with MS Flight Sim and who had to etch his own PCBs, and the solution was really simple.
Get the etch going as above, and then slowly add H2O2 until you see a sudden change in the surface of the copper. It is almost like a clear circle emerging outwards and the PCB, and the etch really starts happening. Sometimes I only pour a little H2O2 in and other times what feels like quite a lot, but the boards etches really quickly, almost before your eyes.
I battled for years with Ferric Chloride and other etchants, this was quite amazing for me. I don't heat the solution at all.
Good luck.
Quote from: gtr2 on December 04, 2013, 10:23:39 PM
I've had this same problem.
My theory is that some of the newer "safer" muratic acid that they sell at the big box stores do not work as well. Also some hydrogen peroxides contain phosphoric acid. Not sure if that matters either.
But the mix that doesn't work well on copper clad can pretty much disintegrate an aluminum enclosure in a few minutes...
I'm definitely not a chemist but I think some of the inert ingredients in some of the products cause the solution to not work as well on copper.
Hey mate,
You can try sulfuric acid instead of hydrochloric acid! 3:1 hydrogen peroxide!
The best would be to use a 30% hydrogen peroxide solution BUT you have to be carefull! You need to create a steong oxidant solution and higher the concentration quicker the etch!
Im still on ferric chloride and quite happy with it. Just heat it up a bit on a hot water bath and the etching takes 15 min..
Cheers
Quote from: peterc on December 05, 2013, 02:59:54 PM
I heard about this combination and how quick it was, couldn't wait to try it.
I went through this same process as you, carefully measuring quantities, getting the right concentration of H2O2, etc.
Took absolute ages. Then I found a webpage (unfortunately gone) about a guy who built his own 737 cockpit to fly in conjunction with MS Flight Sim and who had to etch his own PCBs, and the solution was really simple.
Get the etch going as above, and then slowly add H2O2 until you see a sudden change in the surface of the copper. It is almost like a clear circle emerging outwards and the PCB, and the etch really starts happening. Sometimes I only pour a little H2O2 in and other times what feels like quite a lot, but the boards etches really quickly, almost before your eyes.
I battled for years with Ferric Chloride and other etchants, this was quite amazing for me. I don't heat the solution at all.
Good luck.
This is great info. I usually start with a 2part H2O2 to 1 part Muriatic Acid. If the etch solution isn't working well, just add more H2O2.
Also, in the states we have two national hardware stores...Lowe's and Home Depot. I forget which one, but one store only carries the "safer" muriatic acid (which doesn't work as well as the regular "non-safe"). A gallon of acid will last you for many, many etches and hydrogen peroxide is readily available anywhere.
I also highly recommend floating your plastic etch container in another plastic container of hot water which really speeds up the etch. About 5 minutes (10 min max) seems to do the trick. Gently swish it from side to side to move the liquid around. Just please be safe, wear safety glasses, do it outside in a well ventilated area, and don't breathe the fumes.
Quote from: rullywowr on December 05, 2013, 05:03:37 PMIf the etch solution isn't working well, just add more H2O2.
That would be the best thing to do. What activates the acid is the oxygen; not enough oxygen = slow action. But the more you add H2O2, the more you dilute the muriatic acid (this is why the stronger 30% hydrogen peroxide is better), so you have to find a balance. I read that some people just "add oxygen" by letting the acid container open for a while, but it may be worth a try (provided there is no child or pet around).
I am going to try to make some of this stuff!
Just be sure to do it in a well ventilated area. I'd also recommend wearing some sort of mask when handling the HCl, it tends to fume up when you first open it, and doesn't feel too great in the nose.
Quote from: Gledison on December 05, 2013, 04:53:21 PM
Quote from: gtr2 on December 04, 2013, 10:23:39 PM
I've had this same problem.
My theory is that some of the newer "safer" muratic acid that they sell at the big box stores do not work as well. Also some hydrogen peroxides contain phosphoric acid. Not sure if that matters either.
But the mix that doesn't work well on copper clad can pretty much disintegrate an aluminum enclosure in a few minutes...
I'm definitely not a chemist but I think some of the inert ingredients in some of the products cause the solution to not work as well on copper.
Hey mate,
You can try sulfuric acid instead of hydrochloric acid! 3:1 hydrogen peroxide!
The best would be to use a 30% hydrogen peroxide solution BUT you have to be carefull! You need to create a steong oxidant solution and higher the concentration quicker the etch!
Im still on ferric chloride and quite happy with it. Just heat it up a bit on a hot water bath and the etching takes 15 min..
Cheers
Sorry to jump on the train so late (didn't see the thread in December), but I have to intervene here!
DO NOT EVER, EVER, EVER mix sulfuric acid with hydrogen peroxide, especially in their concentrated forms! This stuff is for professionals only and we hardly ever use it! It forms peroxodisulfuric acid, which is also called Piranha solution. It is one of the most aggressive acids I know of and I only use it to clean porous glass filters, if nothing else does the job.
This stuff forms EXPLOSIVE compounds (I know of some rather unpleasant accidents), so please DO NOT use this stuff. If anything, it will also eat your protective coating (photoresist or toner transfer) and possibly your epoxy substrate.
As for hydrochloric acid (muriatic acid) with H2O2, I also have to advise you to work with safety goggles, gloves and in a well ventilated area! You will form chlorine gas, which is toxic (gives nice lung edema) and also a strung oxidizing agent. I only used ironchloride so far and that has done the trick for me. If you really want to use muriatic acid and H2O2, just dose enough of the peroxide so you see a reaction going on. For your own safety, I recommend not taking to much of it.
I got 30 percent H2O2 at a beauty supply store. I don't think its any more hazardous than the acid. You need to be super careful with both. It was about $2 for 4 oz. and I mix 2 parts HCl to 1 part H2O2. Etches take 5-10 minutes rather than 30-60 minutes.
as long as you take the necessary precautions you're good. As stated before, HCl is dangerous, since it's corrosive and also releases HCl gas especially in the beginning when the bottle is fresh, so do not inhale those fumes.
H2O2 will gives you skin irritations (white splotches) and will bleach your clothes. Contents of over 25% are considered explosive (H2O2 is a metastable compound and will decompose to H2O and O2), so be specially careful with those.
With a fresh mix of 3% peroxide and HCl i don't think i've ever been longer then 5minutes for an etch. From taking a pcb transparency from the printer to having the etched board in hand ready for drilling ~30 minutes, add a few minutes before if you need to size a piece of raw pcb.
They use H2O2 to bleach the tripes at work (soda ash is put in as well).
During the chemical training course we are warned that if it gets on your skin, it will burn and burn and not stop until it either runs out, or reaches either bone or the other side, I forget which.
Combined with the problem of DISPOSING of the damn stuff in a safe, ecologically sound manner, I'd rather just give Keefe money to do my etching.
Quote from: alanp on June 23, 2014, 08:08:03 PM
They use H2O2 to bleach the tripes at work (soda ash is put in as well).
During the chemical training course we are warned that if it gets on your skin, it will burn and burn and not stop until it either runs out, or reaches either bone or the other side, I forget which.
Combined with the problem of DISPOSING of the damn stuff in a safe, ecologically sound manner, I'd rather just give Keefe money to do my etching.
Oh man, they really wanted to scare you. H2O2 is explosive in high concentrations (as mentioned above it decomposes forming oxygen gas, and every "burning" reaction goes faster if there is more oxygen than the usual 20% in air). Also it will have serious affects when it gets in your eyes, swallowed or any of that sort. With skin though, you will just get a white, irritating burning stain, which will peel off the skin after some time (kind of like sunburn, but white). It will, however, surely not eat through you (especially not your bone).
We had one assistant who went up to a student, who was complaining that his reaction did not work. the assistants response? he put a few drops of the h2o2 on his fingers and said: "not getting white. not good anymore" (read with a russian accent) :D Not so corrosive after all...
The conclusion is that you always have to know what you're doing and take the right precautions. I did not yet do anything with high voltages, since I still lack experience. Same applies to chemicals I guess. If you do not know how they will react with each other or what hazards they have, look it up or let a professional do it for you.
So m-Kresol, you seem to be the resident chemical expert, so if someone uses a Muriatic Acid & H2O2 mix to etch boards, what is the best way to neutralize is before you properly dispose of it? I've always read that Washing Soda (which I think may be sodium carbonate?) is effective. Would you know if that is true? One of the reasons I stopped etching was because I never new the proper way to do it. Our county does a yearly (yes, only once a year) hazardous waste collection day. Wish it was more than that.
The good part of using the HCl/H2O2 etchant is that, as I understand it, you don't need to dispose of it for a long time. See the following:
http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/ (http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/)
i have been etching with muriatic and h2o2 for a few years now, and my lung feels GREAT!
but seriously, i etch in tupperware and i set it up right next to the garage door, which is open when i etch. so i'm practically outside when i do it. i snap the tupper lid on it when i'm done. no problems that i know of yet, but you have to be careful when you take the lid off the acid jug. don't breathe next to the undiluted stuff or it'll get ya for sure. very fum-ey!.
The drugstore peroxide i buy is sold for cleaning wounds so not very hazardous. Bottle directions: Use full strength as required for open sores, cuts, wounds, abrasions and insect bites. Keep in a cool dark place.
No hazardous waste pick up here, ever, but there are a few (municipal) drop off centers open at least six days week.
Never had any success with the regeneration of the mix. i use the smallest plastic container big enough for the board to lie flat in and mix up just enough to wash over the board. Consider it a one shot mix maybe a tablespoon at a time.
Quote from: m-Kresol on June 23, 2014, 08:59:04 PM
Oh man, they really wanted to scare you. H2O2 is explosive in high concentrations (as mentioned above it decomposes forming oxygen gas, and every "burning" reaction goes faster if there is more oxygen than the usual 20% in air). Also it will have serious affects when it gets in your eyes, swallowed or any of that sort. With skin though, you will just get a white, irritating burning stain, which will peel off the skin after some time (kind of like sunburn, but white). It will, however, surely not eat through you (especially not your bone).
We had one assistant who went up to a student, who was complaining that his reaction did not work. the assistants response? he put a few drops of the h2o2 on his fingers and said: "not getting white. not good anymore" (read with a russian accent) :D Not so corrosive after all...
The conclusion is that you always have to know what you're doing and take the right precautions. I did not yet do anything with high voltages, since I still lack experience. Same applies to chemicals I guess. If you do not know how they will react with each other or what hazards they have, look it up or let a professional do it for you.
The stuff at work comes in big drums, and is pretty concentrated (don't know the exact figure.)
I use h202 and muriatic acid in a well ventilated area with great results I like to warm it on my toaster oven for better etching. Just don't breathe in the fumes.
Quote from: irmcdermott on June 23, 2014, 09:24:34 PM
So m-Kresol, you seem to be the resident chemical expert, so if someone uses a Muriatic Acid & H2O2 mix to etch boards, what is the best way to neutralize is before you properly dispose of it? I've always read that Washing Soda (which I think may be sodium carbonate?) is effective. Would you know if that is true? One of the reasons I stopped etching was because I never new the proper way to do it. Our county does a yearly (yes, only once a year) hazardous waste collection day. Wish it was more than that.
You can neutralize the acid with sodium carbonate. This will lead to quite strong gas formation (CO2) just to be warned. So just at it a spoon at a time, so not to spill the acid. When the degasing stopps, the solution is near neutral, just slightly basic. I would still not recommend pouring it down the drain. Not because it will harm your pipes or anything, but rather because copper and aluminum chlorides or whatever compounds you have after etching do not belong there and should be collected and disposed of in a more responsible fashion. Too bad they don't collect it more often at your place.
But as Keefe stated above, the etching solution should be good for quite a few etches. I use iron chloride, which can be kind of regenerated by adding a little bit of hydrochloric acid.
Hope I could help, cheers.
Thanks!
Quote from: m-Kresol on June 23, 2014, 06:29:21 PM
Quote from: Gledison on December 05, 2013, 04:53:21 PM
Quote from: gtr2 on December 04, 2013, 10:23:39 PM
I've had this same problem.
My theory is that some of the newer "safer" muratic acid that they sell at the big box stores do not work as well. Also some hydrogen peroxides contain phosphoric acid. Not sure if that matters either.
But the mix that doesn't work well on copper clad can pretty much disintegrate an aluminum enclosure in a few minutes...
I'm definitely not a chemist but I think some of the inert ingredients in some of the products cause the solution to not work as well on copper.
Hey mate,
You can try sulfuric acid instead of hydrochloric acid! 3:1 hydrogen peroxide!
The best would be to use a 30% hydrogen peroxide solution BUT you have to be carefull! You need to create a steong oxidant solution and higher the concentration quicker the etch!
Im still on ferric chloride and quite happy with it. Just heat it up a bit on a hot water bath and the etching takes 15 min..
Cheers
Sorry to jump on the train so late (didn't see the thread in December), but I have to intervene here! DO NOT EVER, EVER, EVER mix sulfuric acid with hydrogen peroxide, especially in their concentrated forms! This stuff is for professionals only and we hardly ever use it! It forms peroxodisulfuric acid, which is also called Piranha solution. It is one of the most aggressive acids I know of and I only use it to clean porous glass filters, if nothing else does the job.
This stuff forms EXPLOSIVE compounds (I know of some rather unpleasant accidents), so please DO NOT use this stuff. If anything, it will also eat your protective coating (photoresist or toner transfer) and possibly your epoxy substrate.
As for hydrochloric acid (muriatic acid) with H2O2, I also have to advise you to work with safety goggles, gloves and in a well ventilated area! You will form chlorine gas, which is toxic (gives nice lung edema) and also a strung oxidizing agent. I only used ironchloride so far and that has done the trick for me. If you really want to use muriatic acid and H2O2, just dose enough of the peroxide so you see a reaction going on. For your own safety, I recommend not taking to much of it.
Mate, that's why I said 'carefull' . I assume people know that they are handling harsh chemicals. You are totally right with caring of peroxides. They should not be kept at home unless under cold temperatures and used by people that know what are doing.
That's why I'm still suggesting ferric chloride. Might not be the greatest one, but is safe regarding possible explosions. ;)