Oh sorry, I forgot to mention the hydrometer. I've only seen
1.100 to 1.200 g/mL range. Any equipment that is used for doing a
measurement then I don't recommend no name brands. This stuff is
only for education purposes. I originally tried to save a few
dollars and bought by first lab equipment from an educational
supply that had cheap plastic burettes, glass hydrometers. I
later bought proper brand name glassware that come with a
specified tolerance. When I compared readings to no name brand
equipment the differences were very high. >30% error for
hydrometer and 4% error for the burette. When making measurement
you should some idea of the tolerance of the instrument being
used. Otherwise you are wasting your money.
Luther m stroud mentioned, having all this lab equipment might be
an overkill. He brings up a good point. How about setting up your
etching tank and start etching circuit boards before investing in
some lab ware. You don't need any fancy equipment to prepare the
copper etchant. Only some kitchen scales and measuring jugs.
Later, when your etchant starts to become exhausted you may
decide to buy the equipment and restore the etchant.
Adam
grantfair2001 wrote:
> Thanks again Adam.
>
> The Rex Allers article suggests obtaining a hydrometer to monitor the
> density of the etchant, which should start out at a density of 1.17
> g/mL, and will increase as copper dissolves into the solution. He
> suggests a hydrometer with an expanded scale of 1.15 to 1.25 g/mL.
> According to my tentative understanding a range of 19 to 31 Baume
> would work here, does this seem right?
>
> I note that American Science and Surplus has some Chinex lab glassware
> (student grade) at low prices. The beaker and erlenmeyer flasks are
> available in the sizes you suggest:
>
> http://www.sciplus.com/category.cfm?subsection=4
>
> Would any of their pipettes do the trick?
>
> The Rex Allers article shows titration using the burette and beaker,
> is the erlenmyer flask better in some way?
>
> Grant
>
> --- 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.
>
>
>
>
>
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