Homebrew PCBs

They are probably no good, metal parts, really low quality, low
volume, likely dead in a short time.

Sureflow or flowjet diaphragm water pumps work and have sufficient
power, one is better suited than the other (no metal bolts) but i
don't remember which check the archives.

ST

On Wed, Mar 19, 2008 at 9:22 PM, garydeal <garydeal@...> wrote:
> Hey, has anyone tried using automotive windshield-wiper fluid pumps to
> spray etchant? In particular, HCl/H2O2 etchant?
>
> Or maybe taken any apart to see if the fluid path is all-plastic? (no
> pesky metal to dissolve?)
>
> Alternatively, is there a suitable small pump available for under say,
> $40? I wouldn't need all that much volume/minute, and just enough
> pressure to get a nozzle to spray reasonably well.
>
> -Gary
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>

Hey, has anyone tried using automotive windshield-wiper fluid pumps to 
spray etchant? In particular, HCl/H2O2 etchant?

Or maybe taken any apart to see if the fluid path is all-plastic? (no 
pesky metal to dissolve?)

Alternatively, is there a suitable small pump available for under say, 
$40? I wouldn't need all that much volume/minute, and just enough 
pressure to get a nozzle to spray reasonably well.

-Gary

Gary

I use a "Waterwerks wwp3000n" pond pump which is able to pump water up 
to the height of 2.5 meters and does 3000 liters per hour (in other 
words about 8.2 feets high and  792 gallons per hour) which works very 
well. The rotor of the pump is acutally all coverd with plastics and so 
is the housing it resides in. There are absolutely no metal parts within 
the stream of the fluid. It was slightly more expensive here (~$50) but 
prices are higher here than in most parts of the world so your mileage 
may varry. The nice thing about the pump is that it's designed to be 
directly put into the pond alsas you could put it directly into the 
etchant (even the power cord is isolated good enough to withstand 
etchants) which greatly simplfies the design of a spray etcher. Might be 
that the pump is not available where you live, but I'm sure similar 
products should. Usually the pump housing of these pumps can be opened 
easily and therefore you could check in the store before you buy it 
wether it suits your needs or not.

HTH

Markus

garydeal schrieb:

>
> Hey, has anyone tried using automotive windshield-wiper fluid pumps to
> spray etchant? In particular, HCl/H2O2 etchant?
>
> Or maybe taken any apart to see if the fluid path is all-plastic? (no
> pesky metal to dissolve?)
>
> Alternatively, is there a suitable small pump available for under say,
> $40? I wouldn't need all that much volume/minute, and just enough
> pressure to get a nozzle to spray reasonably well.
>
> -Gary
>
>

garydeal wrote:
> Hey, has anyone tried using automotive windshield-wiper fluid pumps to 
> spray etchant? In particular, HCl/H2O2 etchant?
> 
> Or maybe taken any apart to see if the fluid path is all-plastic? (no 
> pesky metal to dissolve?)
> 
> Alternatively, is there a suitable small pump available for under say, 
> $40? I wouldn't need all that much volume/minute, and just enough 
> pressure to get a nozzle to spray reasonably well.
> 

The last statement "just enough to get a nozzle to spray reasonably 
well" means you need at least 0.7 bar, or 7 meter head. You are correct 
in that you don't need all that much flow rate. Not sure what pump you 
had in mind but the magnetic drive pumps won't properly spray until you 
get into the $1000+ , 1kW+ range. I suggest you use diaphragm pumps like 
in the spray etcher I made ( see 
http://members.optusnet.com.au/~eseychell/PCB/SprayEtcher/index.html ),
has about 28 meter head (2.8 bar), and still working well after 2 years. 
Shop around for Flowjet brand pumps at caravan sellers.

Any aquarium pump intended for salt water should work.

garydeal wrote:

> Hey, has anyone tried using automotive windshield-wiper fluid pumps to 
> spray etchant? In particular, HCl/H2O2 etchant?
>
> Or maybe taken any apart to see if the fluid path is all-plastic? (no 
> pesky metal to dissolve?)
>
> Alternatively, is there a suitable small pump available for under say, 
> $40? I wouldn't need all that much volume/minute, and just enough 
> pressure to get a nozzle to spray reasonably well.
>
> -Gary
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>