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.
