Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list  

Subject: Re: [Homebrew_PCBs] Old Dynaart equipment and Sodium Persulfate

From: Harvey White <madyn@...>
Date: 2012-02-26

On Sun, 26 Feb 2012 09:32:25 -0500, you wrote:

>On Wed, Feb 15, 2012 at 4:11 PM, Harvey White <madyn@...> wrote:
>
>> ∗∗
>>
>>
>>
>> I was wondering if anyone had either of these pieces of equipment and
>> if they had any particular pointers. As I mentioned, the superfuser
>> seems to be able to do the job in 1 pass.
>>
>> Harvey
>>
>>
>I had an older model of the tank. Don't know if there are any design
>changes on your model.

A lot, from what I can see.

Minimal: one heater rather than two.

Significant: Entire box is made of transparent acrylic. From what I
can see, the original one was made as an insert on a plastic (gray)
file box.

Same: Pumps, though. You must have the pumps running to heat the
etchant.

>
>I think I used ammonium persulfate (may have been sodium) in the tank.
>Worked well, but does need a fair amount of enchant in the sump of the
>tank, also the enchant has a limited life span once it's dissolved in water.

Yep, so does Hydrogen Peroxide/Muriatic acid without adding more
oxygen. I figured that one in.

>
> I had problems with the magnetic impellers on the pumps falling apart. Get
>spares. Don't store enchant in the tank. Especially any enchant that tends
>to crystallize.

Ah, then I'll drain it out. Thanks.

> Think it permeates the sintered magnetic material on the impellers and
>cracks them. (a lot of guesswork here).

Possibly. I know that the peroxide etchant eats bubble stones, or at
least, the ferric chloride does.

Oh, and for experiments, there's a shock product for pools that is
about 4 something/lb, contains potassium monopersulfate. Two bags of
that in a gallon of water will etch boards, about 9 dollars/load,
though. Need to find a cheaper source of the pure stuff.

Note: you want to make sure that there are no air bubbles on the
board. I had a board where the holes in the pads did not etch
properly due to air bubbles.

Thanks,

Harvey

>
>-carl
>
>
>
>
>
>
>
>>
>>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>