So I want to build a bubble tank. Anybody have any best methods or DIY plans? I am pretty sure my boards will remain small for the foreseeable future so I don't think I need an aquarium. :) I assume plastic is the best after glass and likely no metal parts touching the solution. An aquarium pump should work, proven designs are what I am after.
Thanks
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On 06/03/19 01:09, Dave wrote: So I want to build a bubble tank. Anybody have any best methods or DIY plans? I am pretty sure my boards will remain small for the foreseeable future so I don't think I need an aquarium. :) I assume plastic is the best after glass and likely no metal parts touching the solution. An aquarium pump should work, proven designs are what I am after. <>
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On 06/03/19 01:09, Dave wrote: So I want to build a bubble tank. Anybody have any best methods or DIY plans? I am pretty sure my boards will remain small for the foreseeable future so I don't think I need an aquarium. :) I assume plastic is the best after glass and likely no metal parts touching the solution. An aquarium pump should work, proven designs are what I am after. <> <> I got mine cheap from a hamfest.
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Thanks. I had found that one earlier today. It has been replace by a more expensive model. After a lot of searching online, it looks as though I just need to look for a suitable container, get a pump, and a heater. The proper shaped glass vase or something.
toggle quoted message
Show quoted text
On 3/5/2019 8:19 AM, russell shaw wrote: On 06/03/19 01:09, Dave wrote:
So I want to build a bubble tank. Anybody have any best methods or DIY plans? I am pretty sure my boards will remain small for the foreseeable future so I don't think I need an aquarium. :) I assume plastic is the best after glass and likely no metal parts touching the solution. An aquarium pump should work, proven designs are what I am after.
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On Tue, 5 Mar 2019 08:26:04 -0600, you wrote: Thanks. I had found that one earlier today. It has been replace by a more expensive model. After a lot of searching online, it looks as though I just need to look for a suitable container, get a pump, and a heater. The proper shaped glass vase or something. Glass is better. The etchant tends to eat the seal on rubbermaid containers, but will work. You could use an air bubbler stone, but that will be attacked by the acid. At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days. Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do. I've seen designs that are effectively spray etchers, rotating cylinders with holes in them. Normal water pipes (schedule 20 or so) do not get affected by the acid, so an "L" of that plastic with small holes drilled in it, fed outside by an air pump will handle the bubbler. Your tank needs to be level for a good bubble flow. Harvey On 3/5/2019 8:19 AM, russell shaw wrote:
On 06/03/19 01:09, Dave wrote:
So I want to build a bubble tank. Anybody have any best methods or DIY plans? I am pretty sure my boards will remain small for the foreseeable future so I don't think I need an aquarium. :) I assume plastic is the best after glass and likely no metal parts touching the solution. An aquarium pump should work, proven designs are what I am after.
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On 3/5/2019 10:28 AM, Harvey White wrote: On Tue, 5 Mar 2019 08:26:04 -0600, you wrote:
Thanks. I had found that one earlier today. It has been replace by a more expensive model. After a lot of searching online, it looks as though I just need to look for a suitable container, get a pump, and a heater. The proper shaped glass vase or something. Glass is better. The etchant tends to eat the seal on rubbermaid containers, but will work. You could use an air bubbler stone, but that will be attacked by the acid. At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days.
Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do. I've seen designs that are effectively spray etchers, rotating cylinders with holes in them. Normal water pipes (schedule 20 or so) do not get affected by the acid, so an "L" of that plastic with small holes drilled in it, fed outside by an air pump will handle the bubbler.
Your tank needs to be level for a good bubble flow.
Harvey I was just looking at those 8x8 inch square glass blocks as an easy container. The ones that have the rectangular hole already cut in them. May make a good starter bubble tank. So now I already have my first problem. Finding a plastic suitable for my HCL based etchant. :) Or change etchants already... I want to stick with the muriatic and peroxide for now.
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Hello Dave.
AmericanRadioHistory.com has scanned many old magazines including
Radio Electronics.?
Look at Radio Electronics for December 1989.? The table of
contents says page 45 but it actually is page 41, at least as far
as Adobe pages go.? The direct link to the magazine (entire issue)
is:
The article title was "Make Your Own Etching Tank" by Tony Lewis.
I built several of these after that article came out.? Why
several, you ask.? Because it was easier to make a tank the size I
needed so I did not have to have too much etchant open at any one
time.? The size as shown in the article is a great size for these
days but back then I was trying to make some large boards.? The
WeldOn #3 or #4 solvent/glue is much easier to find these days
than it was then.
Good luck.
Jim Pruitt
On 3/5/2019 6:09 AM, Dave wrote:
toggle quoted message
Show quoted text
So I want
to build a bubble tank. Anybody have any best methods or DIY
plans? I am pretty sure my boards will remain small for the
foreseeable future so I don't think I need an aquarium. :) I
assume plastic is the best after glass and likely no metal parts
touching the solution. An aquarium pump should work, proven
designs are what I am after.
Thanks
.
|
Hello Dave On 3/5/2019 9:21 AM, Dave wrote: Glass is better.? The etchant tends to eat the seal on rubbermaid
containers, but will work.? You could use an air bubbler stone, but that will be attacked by the acid.? At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days.
Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do.? I've seen designs that are effectively spray etchers, rotating cylinders with holes in them.? Normal water pipes (schedule 20 or so) do not get affected by the acid, so an "L" of that plastic with small holes drilled in it, fed outside by an air pump will handle the bubbler.
Your tank needs to be level for a good bubble flow.
Harvey I was just looking at those 8x8 inch square glass blocks as an easy container. The ones that have the rectangular hole already cut in them. May make a good starter bubble tank. So now I already have my first problem. Finding a plastic suitable for my HCL based etchant. :) Or change etchants already... I want to stick with the muriatic and peroxide for now. The DIY etch tank I referenced in Radio Electronics Magazine for December 1989 ?had you buying acrylic (aka Plexiglass) sheeting and cutting it to the sizes you needed. Then using a solvent glue (WeldOn #3 or #4--or acetone works too I think) and gluing the container together.? It also had you build a carrier so you did not have to fish the board out of the warm etchant.? It used fish tank air pumps and fish tank heaters.? I think places like McMaster Carr have the solvent and probably the plexiglass or if you have a local plastic shop (maybe a sign shop) often have it and will even cut the size(s) for you for a fee, at least the plastic shops.? Also places like Ace Hardware and to a much lesser extent Lowes and Home Depot have acrylic but usually not the 1/4" (6mm) thick that was used in this article. I liked that arrangement because it allowed me to make several tanks the size I wanted or needed. Good luck. Jim Pruitt
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NOT saying DO NOT build a heated bubbler etching
tank ......
but
for any newbies doing it for the first
time........
you don't need heat or bubbles.
I've been etching for 4 years on my kitchen
counter at room temperature and in summer in 65 degree crisp
cold air conditioning
and
never have seen any deviation in my HCL H2O2 etch
bath time.... always between 5 and 7 minutes
and
I periodically wipe bubbles off the copper with a
fan shaped makeup brush and make sure that the metal
ferule on the brush never touches the liquid.
Some guys use rockers to slosh the liquid.
Some guys attach vibrator motors.... the kind in
pagers and cell phones and kink toys...
?to shake away the bubbles that form on the PCB.
?Sometimes I don't even bother with the brush
and
always end up with a pretty PCB.
On 03/05/2019 12:21 PM, Dave wrote:
toggle quoted message
Show quoted text
On
3/5/2019 10:28 AM, Harvey White wrote:
On Tue, 5 Mar 2019 08:26:04 -0600, you
wrote:
Thanks. I had found that one earlier
today. It has been replace by a
more expensive model. After a lot of searching online, it
looks as
though I just need to look for a suitable container, get a
pump, and a
heater. The proper shaped glass vase or something.
Glass is better.? The etchant tends to eat the seal on
rubbermaid
containers, but will work.? You could use an air bubbler stone,
but
that will be attacked by the acid.? At one time, I used an
aquarium
heater to heat the etchant, from what I remember, I stopped that
and
just etched on warm days.
Ammonium persulfate (or perchlorate) does not corrode things the
way
that HCL based etchants do.? I've seen designs that are
effectively
spray etchers, rotating cylinders with holes in them.? Normal
water
pipes (schedule 20 or so) do not get affected by the acid, so an
"L"
of that plastic with small holes drilled in it, fed outside by
an air
pump will handle the bubbler.
Your tank needs to be level for a good bubble flow.
Harvey
I was just looking at those 8x8 inch square glass blocks as an
easy container. The ones that have the rectangular hole already
cut in them. May make a good starter bubble tank. So now I already
have my first problem. Finding a plastic suitable for my HCL based
etchant. :) Or change etchants already... I want to stick with the
muriatic and peroxide for now.
|
On Tue, 5 Mar 2019 13:01:53 -0500, you wrote: NOT saying DO NOT build a heated bubbler etching tank ......
but
for any newbies doing it for the first time........
you don't need heat or bubbles. agitation with new HCL and H2O2. Once it becomes CuCl then you need agitation. Heat will speed up etching. agitation tends to remove "stale" etchant near the board. When you brush the board with etchant using a sponge, you remove the oxidation and don't need agitation. I've been etching for 4 years on my kitchen counter at room temperature and in summer in 65 degree crisp cold air conditioning
and
never have seen any deviation in my HCL H2O2 etch bath time.... always between 5 and 7 minutes
That tends to indicate fresh etchant every time. Since I use a tank, I needed to keep the solution for a while, ended up with about a gallon capacity tank, so different approach. Harvey and
I periodically wipe bubbles off the copper with a fan shaped makeup brush and make sure that the metal
ferule on the brush never touches the liquid.
Some guys use rockers to slosh the liquid.
Some guys attach vibrator motors.... the kind in pagers and cell phones and kink toys...
?to shake away the bubbles that form on the PCB.
?Sometimes I don't even bother with the brush
and
always end up with a pretty PCB.
On 03/05/2019 12:21 PM, Dave wrote:
On 3/5/2019 10:28 AM, Harvey White wrote:
On Tue, 5 Mar 2019 08:26:04 -0600, you wrote:
Thanks. I had found that one earlier today. It has been replace by a more expensive model. After a lot of searching online, it looks as though I just need to look for a suitable container, get a pump, and a heater. The proper shaped glass vase or something. Glass is better.? The etchant tends to eat the seal on rubbermaid containers, but will work.? You could use an air bubbler stone, but that will be attacked by the acid.? At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days.
Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do.? I've seen designs that are effectively spray etchers, rotating cylinders with holes in them.? Normal water pipes (schedule 20 or so) do not get affected by the acid, so an "L" of that plastic with small holes drilled in it, fed outside by an air pump will handle the bubbler.
Your tank needs to be level for a good bubble flow.
Harvey I was just looking at those 8x8 inch square glass blocks as an easy container. The ones that have the rectangular hole already cut in them. May make a good starter bubble tank. So now I already have my first problem. Finding a plastic suitable for my HCL based etchant. :) Or change etchants already... I want to stick with the muriatic and peroxide for now.
|
I dont have plans. because I "winged it" But your free to copy mine. Im 100% satisfied with my setup. https://www.hyperlinks.net/?s=etching&id=m
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On 3/5/2019 11:57 AM, Jim Pruitt wrote: Hello Dave
On 3/5/2019 9:21 AM, Dave wrote:
Glass is better.? The etchant tends to eat the seal on rubbermaid
containers, but will work.? You could use an air bubbler stone, but that will be attacked by the acid.? At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days.
Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do.? I've seen designs that are effectively spray etchers, rotating cylinders with holes in them.? Normal water pipes (schedule 20 or so) do not get affected by the acid, so an "L" of that plastic with small holes drilled in it, fed outside by an air pump will handle the bubbler.
Your tank needs to be level for a good bubble flow.
Harvey I was just looking at those 8x8 inch square glass blocks as an easy container. The ones that have the rectangular hole already cut in them. May make a good starter bubble tank. So now I already have my first problem. Finding a plastic suitable for my HCL based etchant. :) Or change etchants already... I want to stick with the muriatic and peroxide for now. The DIY etch tank I referenced in Radio Electronics Magazine for December 1989 ?had you buying acrylic (aka Plexiglass) sheeting and cutting it to the sizes you needed. Then using a solvent glue (WeldOn #3 or #4--or acetone works too I think) and gluing the container together.? It also had you build a carrier so you did not have to fish the board out of the warm etchant.? It used fish tank air pumps and fish tank heaters.? I think places like McMaster Carr have the solvent and probably the plexiglass or if you have a local plastic shop (maybe a sign shop) often have it and will even cut the size(s) for you for a fee, at least the plastic shops. Also places like Ace Hardware and to a much lesser extent Lowes and Home Depot have acrylic but usually not the 1/4" (6mm) thick that was used in this article.
I liked that arrangement because it allowed me to make several tanks the size I wanted or needed.
Good luck.
Jim Pruitt
Hi Jim,
? I just answered the other message about the Radio magazine instructions so disregard that one. I will call a few sign shops and see what they say and also check out McMaster Carr.
Thanks
|
Hi Rob,
? Funny thing you mention the rocker as Many years ago I bought
some slow rotisserie motors to build a rocker and still have the
parts. I was going to make a wooden cam lobe and have the
tupperware container on a small wide see-saw where the wooden cam
would move the board up and down. I know I don't "need" a bubble
tank but I think it would be pretty nice to have.
Thanks
On 3/5/2019 12:01 PM, Rob via Groups.Io
wrote:
toggle quoted message
Show quoted text
NOT saying DO NOT build a heated bubbler
etching tank ......
but
for any newbies doing it for the first
time........
you don't need heat or bubbles.
I've been etching for 4 years on my kitchen
counter at room temperature and in summer in 65 degree crisp
cold air conditioning
and
never have seen any deviation in my HCL H2O2
etch bath time.... always between 5 and 7 minutes
and
I periodically wipe bubbles off the copper with
a fan shaped makeup brush and make sure that the metal
ferule on the brush never touches the liquid.
Some guys use rockers to slosh the liquid.
Some guys attach vibrator motors.... the kind
in pagers and cell phones and kink toys...
?to shake away the bubbles that form on the
PCB.
?Sometimes I don't even bother with the brush
and
always end up with a pretty PCB.
On 03/05/2019 12:21 PM, Dave wrote:
On
3/5/2019 10:28 AM, Harvey White wrote:
On Tue, 5 Mar 2019 08:26:04 -0600, you
wrote:
Thanks. I had found that one earlier
today. It has been replace by a
more expensive model. After a lot of searching online, it
looks as
though I just need to look for a suitable container, get a
pump, and a
heater. The proper shaped glass vase or something.
Glass is better.? The etchant tends to eat the seal on
rubbermaid
containers, but will work.? You could use an air bubbler
stone, but
that will be attacked by the acid.? At one time, I used an
aquarium
heater to heat the etchant, from what I remember, I stopped
that and
just etched on warm days.
Ammonium persulfate (or perchlorate) does not corrode things
the way
that HCL based etchants do.? I've seen designs that are
effectively
spray etchers, rotating cylinders with holes in them.? Normal
water
pipes (schedule 20 or so) do not get affected by the acid, so
an "L"
of that plastic with small holes drilled in it, fed outside by
an air
pump will handle the bubbler.
Your tank needs to be level for a good bubble flow.
Harvey
I was just looking at those 8x8 inch square glass blocks as an
easy container. The ones that have the rectangular hole already
cut in them. May make a good starter bubble tank. So now I
already have my first problem. Finding a plastic suitable for my
HCL based etchant. :) Or change etchants already... I want to
stick with the muriatic and peroxide for now.
|
Received from Dave at 3/5/2019 05:21 PM UTC: On 3/5/2019 10:28 AM, Harvey White wrote:
On Tue, 5 Mar 2019 08:26:04 -0600, you wrote:
Thanks. I had found that one earlier today. It has been replace by a more expensive model. After a lot of searching online, it looks as though I just need to look for a suitable container, get a pump, and a heater. The proper shaped glass vase or something. Glass is better. The etchant tends to eat the seal on rubbermaid containers, but will work. You could use an air bubbler stone, but that will be attacked by the acid. At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days. Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do.
Ammonium persulfate solution needs to be heated to etch efficiently and heat causes the solution to decompose. It isn't as efficient at etching copper as other more easily obtained chemicals unless the solution is enhanced via the addition of a trace of mercuric sulfate. That's a really big NO NO for anyone without the ability to manage the waste100% legally. Whether or not heated, the solution can't be rejuvenated and must be disposed of when spent... along with any copper it contains. No problem for those who don't care about proper (legal) disposal... a pain in the butt for those who do. I'd forget ammonium persulfate. Ammonium perchlorate sounds similar to ammonium persulfate, but it's a completely different thing. It's a super powerful oxidizer with primary uses being in fireworks and as an ingredient in some solid rocket propellants. I can't find any credible references to using ammonium perchlorate for etching PCBs. The chemistry just isn't right. Use polypropylene or glass and corrosion becomes a non-issue. Note that the material in the soft seal built into the lids of some polypropylene containers isn't polypropylene and could be attacked. That's why I store my solution in a large wide mouth glass jar with a plastic lid left a bit loose to avoid pressure build up. I was just looking at those 8x8 inch square glass blocks as an easy container. The ones that have the rectangular hole already cut in them. May make a good starter bubble tank. So now I already have my first problem. Finding a plastic suitable for my HCL based etchant. :) Or change etchants already... I want to stick with the muriatic and peroxide for now. When it comes to plastic containers, pretty much any polypropylene container from Walmart will do for etching. No lid needed when etching. The recycling symbol for polypropylene is a recycling triangle with "5" or "05" inside and "PP" below, so it's easy to identify. I etch in a plastic pan and store the solution in a glass container with a plastic lid between uses. I use a large 1-gallon or so wide mouth jar that's about half full... and the bubbler tube comes out thru a small hole in the lid... so when bubbling to rejuvenate my solution any minor splashes from the bubbler stay in the jar. If you just use HCl and peroxide and don't let copper build up appreciably in it, there's nothing to rejuvenate so you can forget the rejuvenation part. (But leave the lid a bit loose because H2O2 decomposes to produce oxygen gas and that can cause pressure to build up.) I actually added a fair bit of copper wire to my initial HCl/H2O2 solution because I wanted to let the cupric chloride that forms plus a bit of HCl do the etching... and I rejuvenate the solution with bubbled air rather than adding H2O2. Using this approach the only thing you add is a bit of water to maintain the volume of the solution and a bit of HCl when the solution won't rejuvenate completely to a nice emerald green. That boils down to adding HCl in the amount needed to make up what gets used when etching... and that's not much unless you etch a heck of a lot of boards. It's adequate to just etch until the solution either won't rejuvenate to a bright emeralds green or if you notice that the etching rate is slowing down. I've never noticed the latter. Also, a fritted glass bubbler is NOT affected by the etchant. Stone bubblers (as warned above) maybe, depending on the material, but NOT fritted glass. Fritted glass bubblers are a glass tube with a porous glass bubbler on the end. The stone type will almost always have a plastic tube with a bubbler stone glued/epoxied onto it. The smallest (cheap) vibrating aquarium pump will provide enough air for etching and rejuvenating. You don't need a sheet of bubbles flowing vigorously all over the board, you just need the solution moving around enough to continuously remove the brownish reaction products from the surface of the board. The more you agitate the solution the more undercutting you'll get so a large airflow isn't as desirable as one might think. To it in perspective, you have to etch a heck of a lot of boards to put the slightest strain on a couple of liters of etchant consisting of cupric chloride solution plus HCl. Jim H
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On 3/5/2019 1:56 PM, Jim Higgins wrote: Received from Dave at 3/5/2019 05:21 PM UTC:
On 3/5/2019 10:28 AM, Harvey White wrote:
On Tue, 5 Mar 2019 08:26:04 -0600, you wrote:
Thanks. I had found that one earlier today. It has been replace by a more expensive model. After a lot of searching online, it looks as though I just need to look for a suitable container, get a pump, and a heater. The proper shaped glass vase or something. Glass is better.? The etchant tends to eat the seal on rubbermaid containers, but will work.? You could use an air bubbler stone, but that will be attacked by the acid.? At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days. Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do.
Ammonium persulfate solution needs to be heated to etch efficiently and heat causes the solution to decompose. It isn't as efficient at etching copper as other more easily obtained chemicals unless the solution is enhanced via the addition of a trace of mercuric sulfate. That's a really big NO NO for anyone without the ability to manage the waste100% legally. Whether or not heated, the solution can't be rejuvenated and must be disposed of when spent... along with any copper it contains. No problem for those who don't care about proper (legal) disposal... a pain in the butt for those who do. I'd forget ammonium persulfate.
Ammonium perchlorate sounds similar to ammonium persulfate, but it's a completely different thing. It's a super powerful oxidizer with primary uses being in fireworks and as an ingredient in some solid rocket propellants. I can't find any credible references to using ammonium perchlorate for etching PCBs. The chemistry just isn't right.
Use polypropylene or glass and corrosion becomes a non-issue. Note that the material in the soft seal built into the lids of some polypropylene containers isn't polypropylene and could be attacked. That's why I store my solution in a large wide mouth glass jar with a plastic lid left a bit loose to avoid pressure build up.
I follow the law and don't want to contaminate the environment so I will play it safe. I may just be smart and etch outdoors, reclaim my etchant, and figure out what container can actually keep it from seeping out. Or build a small wooden shed just for chemicals (in plastic bottles).
I was just looking at those 8x8 inch square glass blocks as an easy container. The ones that have the rectangular hole already cut in them. May make a good starter bubble tank. So now I already have my first problem. Finding a plastic suitable for my HCL based etchant. :) Or change etchants already... I want to stick with the muriatic and peroxide for now. When it comes to plastic containers, pretty much any polypropylene container from Walmart will do for etching. No lid needed when etching. The recycling symbol for polypropylene is a recycling triangle with "5" or "05" inside and "PP" below, so it's easy to identify. I etch in a plastic pan and store the solution in a glass container with a plastic lid between uses. I use a large 1-gallon or so wide mouth jar that's about half full... and the bubbler tube comes out thru a small hole in the lid... so when bubbling to rejuvenate my solution any minor splashes from the bubbler stay in the jar. If you just use HCl and peroxide and don't let copper build up appreciably in it, there's nothing to rejuvenate so you can forget the rejuvenation part. (But leave the lid a bit loose because H2O2 decomposes to produce oxygen gas and that can cause pressure to build up.) I actually added a fair bit of copper wire to my initial HCl/H2O2 solution because I wanted to let the cupric chloride that forms plus a bit of HCl do the etching... and I rejuvenate the solution with bubbled air rather than adding H2O2. Using this approach the only thing you add is a bit of water to maintain the volume of the solution and a bit of HCl when the solution won't rejuvenate completely to a nice emerald green. That boils down to adding HCl in the amount needed to make up what gets used when etching... and that's not much unless you etch a heck of a lot of boards. It's adequate to just etch until the solution either won't rejuvenate to a bright emeralds green or if you notice that the etching rate is slowing down. I've never noticed the latter.
Also, a fritted glass bubbler is NOT affected by the etchant. Stone bubblers (as warned above) maybe, depending on the material, but NOT fritted glass. Fritted glass bubblers are a glass tube with a porous glass bubbler on the end. The stone type will almost always have a plastic tube with a bubbler stone glued/epoxied onto it. The smallest (cheap) vibrating aquarium pump will provide enough air for etching and rejuvenating. You don't need a sheet of bubbles flowing vigorously all over the board, you just need the solution moving around enough to continuously remove the brownish reaction products from the surface of the board. The more you agitate the solution the more undercutting you'll get so a large airflow isn't as desirable as one might think.
To it in perspective, you have to etch a heck of a lot of boards to put the slightest strain on a couple of liters of etchant consisting of cupric chloride solution plus HCl.
Jim H
I see people using plastic all the time but thought the square glass block would be interesting. I pretty much understand the rejuvenation part and all that but my main worry is storage and no rusting my stuff in my shop. The info on the fritted glass bubbler is a good tip. I wonder about the plastic tube though that connects it. Will that degrade and if so, how fast? The Radio Electronics article on a bubble tank is something I would like to build and it is only 2 inches wide so I am curious how you would change the hoses out based on the design. I will ask the other Jim about that. And how do you store your etchant safely to avoid rusting any nearby metal/steel? Thanks for all the good info.
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A wood shed assembled with wood pegs, otherwise, you might lose the shed after a while. Just kidding. The muriatic acid is sold in plastic canisters with a good seal. That’s what I use for my etchant as I have a few of those to maintain the PH of my pool. Home Depot sells one galon for less than $10. For the H2O2, I go to the Beauty Salon Supplies shop to get the 30% instead of the 3%.
Jean-Paul N1JPL
toggle quoted message
Show quoted text
On Mar 5, 2019, at 4:55 PM, Dave <theschemer@...> wrote:
On 3/5/2019 1:56 PM, Jim Higgins wrote:
Received from Dave at 3/5/2019 05:21 PM UTC:
On 3/5/2019 10:28 AM, Harvey White wrote:
On Tue, 5 Mar 2019 08:26:04 -0600, you wrote:
Thanks. I had found that one earlier today. It has been replace by a more expensive model. After a lot of searching online, it looks as though I just need to look for a suitable container, get a pump, and a heater. The proper shaped glass vase or something. Glass is better. The etchant tends to eat the seal on rubbermaid containers, but will work. You could use an air bubbler stone, but that will be attacked by the acid. At one time, I used an aquarium heater to heat the etchant, from what I remember, I stopped that and just etched on warm days. Ammonium persulfate (or perchlorate) does not corrode things the way that HCL based etchants do.
Ammonium persulfate solution needs to be heated to etch efficiently and heat causes the solution to decompose. It isn't as efficient at etching copper as other more easily obtained chemicals unless the solution is enhanced via the addition of a trace of mercuric sulfate. That's a really big NO NO for anyone without the ability to manage the waste100% legally. Whether or not heated, the solution can't be rejuvenated and must be disposed of when spent... along with any copper it contains. No problem for those who don't care about proper (legal) disposal... a pain in the butt for those who do. I'd forget ammonium persulfate.
Ammonium perchlorate sounds similar to ammonium persulfate, but it's a completely different thing. It's a super powerful oxidizer with primary uses being in fireworks and as an ingredient in some solid rocket propellants. I can't find any credible references to using ammonium perchlorate for etching PCBs. The chemistry just isn't right.
Use polypropylene or glass and corrosion becomes a non-issue. Note that the material in the soft seal built into the lids of some polypropylene containers isn't polypropylene and could be attacked. That's why I store my solution in a large wide mouth glass jar with a plastic lid left a bit loose to avoid pressure build up.
I follow the law and don't want to contaminate the environment so I will play it safe. I may just be smart and etch outdoors, reclaim my etchant, and figure out what container can actually keep it from seeping out. Or build a small wooden shed just for chemicals (in plastic bottles).
I was just looking at those 8x8 inch square glass blocks as an easy container. The ones that have the rectangular hole already cut in them. May make a good starter bubble tank. So now I already have my first problem. Finding a plastic suitable for my HCL based etchant. :) Or change etchants already... I want to stick with the muriatic and peroxide for now. When it comes to plastic containers, pretty much any polypropylene container from Walmart will do for etching. No lid needed when etching. The recycling symbol for polypropylene is a recycling triangle with "5" or "05" inside and "PP" below, so it's easy to identify. I etch in a plastic pan and store the solution in a glass container with a plastic lid between uses. I use a large 1-gallon or so wide mouth jar that's about half full... and the bubbler tube comes out thru a small hole in the lid... so when bubbling to rejuvenate my solution any minor splashes from the bubbler stay in the jar. If you just use HCl and peroxide and don't let copper build up appreciably in it, there's nothing to rejuvenate so you can forget the rejuvenation part. (But leave the lid a bit loose because H2O2 decomposes to produce oxygen gas and that can cause pressure to build up.) I actually added a fair bit of copper wire to my initial HCl/H2O2 solution because I wanted to let the cupric chloride that forms plus a bit of HCl do the etching... and I rejuvenate the solution with bubbled air rather than adding H2O2. Using this approach the only thing you add is a bit of water to maintain the volume of the solution and a bit of HCl when the solution won't rejuvenate completely to a nice emerald green. That boils down to adding HCl in the amount needed to make up what gets used when etching... and that's not much unless you etch a heck of a lot of boards. It's adequate to just etch until the solution either won't rejuvenate to a bright emeralds green or if you notice that the etching rate is slowing down. I've never noticed the latter.
Also, a fritted glass bubbler is NOT affected by the etchant. Stone bubblers (as warned above) maybe, depending on the material, but NOT fritted glass. Fritted glass bubblers are a glass tube with a porous glass bubbler on the end. The stone type will almost always have a plastic tube with a bubbler stone glued/epoxied onto it. The smallest (cheap) vibrating aquarium pump will provide enough air for etching and rejuvenating. You don't need a sheet of bubbles flowing vigorously all over the board, you just need the solution moving around enough to continuously remove the brownish reaction products from the surface of the board. The more you agitate the solution the more undercutting you'll get so a large airflow isn't as desirable as one might think.
To it in perspective, you have to etch a heck of a lot of boards to put the slightest strain on a couple of liters of etchant consisting of cupric chloride solution plus HCl.
Jim H
I see people using plastic all the time but thought the square glass block would be interesting. I pretty much understand the rejuvenation part and all that but my main worry is storage and no rusting my stuff in my shop. The info on the fritted glass bubbler is a good tip. I wonder about the plastic tube though that connects it. Will that degrade and if so, how fast? The Radio Electronics article on a bubble tank is something I would like to build and it is only 2 inches wide so I am curious how you would change the hoses out based on the design. I will ask the other Jim about that. And how do you store your etchant safely to avoid rusting any nearby metal/steel? Thanks for all the good info.
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This link hopefully will show my tank which has lasted five years so far. It is a jug intended to fit in the door of a refrigerator. It's fairly slim so keeping the amount of etching liquid needed to a minimum. Fish tank heater and bubble device.
Usual thing with dropbox. You are invited to create an account and you can say "no". Then you will be asked to install Flash Player, well that's up to you. I wouldn't. Or you can just click "download" (top right hand side) to see the video.
72/3 Tony G4WIF
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Hey there! Seems the link doesnt work for me - error 404 - "That file isn’t here anymore".
Best regards,
Phil.
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Yeah, you have to logged in to see the
file.? I got the same message then I logged in.? Message shouldbe changed to?:
you have to be logged in to see this file.? Very crappy programming.?
?
J?J
?
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Seems the link doesnt work for me - error 404 - "That file
isn’t here anymore".
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I can't see it and I even went through the whole install dropbox
thing. :-(
Dave
toggle quoted message
Show quoted text
[Edited Message Follows]
This link hopefully will show my tank which has lasted five years
so far. It is a jug intended to fit in the door of a refrigerator.
It's fairly slim so keeping the amount of etching liquid needed to
a minimum. Fish tank heater and bubble device.
Usual thing with dropbox. You are invited to create an account and
you can say "no". Then you will be asked to install Flash Player,
well that's up to you. I wouldn't.
Or you can just click "download" (top right hand side) to see the
video.
72/3
Tony G4WIF
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