Material for scrubbing Cu-clad boards

Yup..That's what I use. Or whatever generic synthetic scouring pad I can get.

In the past I've tried Rag with abrasive( Vim, toothpaste, baking soda),400 grit wet sanding paper, copper wool and steel wool.

Scotchbrite also removes the burrs that you get from x-acto hacking copperclad to make prototypes.

This one

ftp://jjlarkin.lmi.net/BB_fast.JPG

was hand-hacked and then scrubbed hard with soapy water and Scotchbrite. Solder practically leaps onto it, at least for a few days until it tarnishes. That's an EL gate driving a gaasfet, making a

John

...

He probably is in or near Tripura, Mizoram, or Manipur, some Indian States that are 300-500 Km east of Kolkata.

Archimedes' Lever wibbled on Tuesday 16 March 2010 11:55

I've used those blocks after etching to get nice bright copper prior to a quick spray of hobby grade conformal coating. 000 grade (super fine) steel wool would be OK too, as long as you wash all the strands off afterwards.

It depends on the acid. Ferric chloride, which is popular among hobbyists, is stopped even by a fingerprint.

If you use toner transfer, it is essential that the copper is clean, otherwise the toner will not stick reliably.

That's right. I'm in Aizawl, Mizoram.

A laser printer prints on both conductive and non-conductive surfaces, but you want clean copper because you want the resist directly on the copper, not on a fingerprint.

Neat, India to the East of Bangladesh.

After many years of research and cribbing from professional PCB manufacturer techniques. There is a trick to this. Industrial manufacturers go alkaline clean. A good product with NaOH detergent like dish washing detergent. Then a weak acid cleaner. like 5% Ammonium Persulfate. This microetchs the surface to allow good adhesion of the dry film. The acid removes the copper oxide while the alkaline solution strips any grease from fingerprints etc.

Yep. Joined to the main part of India by a narrow strip of Indian territory to the north-west of Bangladesh.