Homebrew_PCBs

For a etching tank, I used a tupper "juice" pitcher which can be
purchased from the local grocery store or around here in NJ... the
99-cent stores.

I haven't run into problems with an imbalanced etching solution yet,
but if I did notice sludging that didn't clear up with aeration, I
imagine one
could buy a beer/wine hygrometer for cheap
( http://brewsupplies.com/cgi-bin/quikstore.cgi has them for $5 a
piece ).

and if the sludging still didn't clear up after correcting the sp
density of the water,
then it can be assumed that the solution may need more HCl.
At which point I would add a nonscientific "dash" to the bath every
now and then
until the sludge cleared up.

All that laboratory equipment seems like a bit of overkill to
maintain a simple
bath of CuCl etchant - which doesn't really need a precise PH to
perform
its duty.

--- In Homebrew_PCBs@yahoogroups.com, adam Seychell
<adam_seychell@y...> wrote:

> No reason I can think of. picnic coolers are cheap, and have a good

lid. I built

> my tanks because I needed those dimensions. I coudnl't find

anything off the

> shelf that was narrow and deep enough, base = 45x250mm high = 350

mm.

> Any of the food plastics are ok with strong acids.
> Now you only concern is getting hold of some lab equipment.
>
> Here is lab order list.
>
> 1 * 5 ml class B volumetric pipette
> (preferred to graduated pipette)
> (buy a second in case you break it)
> 1 * rubber bulb pipette sucker
> 1 * 125 ml dropper bottle for indicator (makes life easier)
> 1 * 50 ml glass burette, class B.
> 1 * 0-50°C (or 0-100°C) glass thermometer
> 1 * 250 ml erlenmeyer flask
> 1 * Bromophenol Blue indicator
> (1 gram will last you ever and a day)
>
>
> You also have to make some kind of stand to hold the burette, I

made something

> out of wood that was a *LOT* cheaper than buying a dedicated stand.

Fasten the

> burette with rubber bands to a length of wood, and hold that by a

stand from a

> heavy base using a diagonal pole. The area under the burette nozzle

needs to be

> free to place the erlenmeyer flask.
>
> The deionized water and sodium hydroxide is available from most

supermarkets.

> You also need some ethanol to make up the bromophenol blue

indicator. Its

> probably better to get the right indicator rather trying to use

turmeric power

> because it will be easier to see the end point of the titration,

which makes the

> job easier to carry out.
>
>
> > Thanks Adam - this is helpful advice. Is there any reason not to

use a

> > plastic picnic cooler? I believe these are PVC.
> >
> > Grant
>
> >