Homebrew PCBs

It just so happens my current project is building a spray
etcher. I asked this same question on this group a month or
two ago and since then I done some research on spray 
etching. The pressure should be at least 1 bar for the 
nozzles to be effective. I looked for several weeks for a 
suitable pump. The magnetic drive centrifuge pumps may seem 
ideal for pumping etchant however the smaller and more 
affordable pumps of this type do not deliver the required 
pressures.

The pump I recommend is a 12V electric diaphragm pump used 
for pumping water in recreational vehicles.
The two main manufactures of small 12V electric diaphragm
pumps are Shurflo and Flojet.
Two models were available in my city for reasonable price.
FLojet "Quad II Diaphragm" 4406 series
Shurflo "Aqua King Premier" 2088-422-144

I contacted both manufactures to check for chemical
compatibility, and both replied listing the wetted
materials. Both manufactures used same materials for each
component.

Housing: glass filled polypropylene
Valves: EPDM
Diaphragm: Santoprene

All these materials are compatible with chemicals found in 
common etchants.

I bought the Shurflo 2088-422-144 because it was slightly
higher pressure and Shurflo have more data on their pumps.
I have bench tested the pump and found the pump can happily
deliver 180 kPa at 6.1 liters/minute with 12.1 volts at 5.5
amps.
I found the motor will not run for more than 20 ~ 30 minutes
continuously due to thermal cutout protection. Some
cooling of the motor housing would be necessary for it to
run longer.  Check out the Shurflo 2088-343-135 for better 
performance.




Hope this helps

Adam


mpdickens wrote:
> Does anyone on the list have a specific pump
> (Manufacturer and part number) that they can recommend
> for spray etching? It would be most helpful if the
> recommendation was based on personal experience.
> 
> 
> Best regards
> 
> 
> Marvin Dickens
> Alpharetta, Georgia  USA
> 
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