Bubble bar/wall - not a air stone

Nope. But I use bubble tubing. It creates small bubbles but works ver

well. The cool part is you can make a froth tank with it. Etch faster :)

(Works only on single sided cards though...)

Basically you take a shallow pan and cover the bottom with a spiral o zig-zag pattern of bubble tubing. Then you add some small plasti needles as spacers. Now you place the card with the side you want to etch down and star the bubbler. The card should rest a very very small tad abowe the surface and th bubbles would froth up onto the card. Etching is very fast and i removes the used etchand very effectively from the board as it goes. Paralelling the bubble tubing with heating wire or similar is a goo way to add heater to the tank too

-- KreAtur

----------------------------------------------------------------------- KreAture's Profile:

--Etching, eh? What liquids must the thing survive? I'm thinking you might want to use stainless. IIRC there are some widgets available at pneumatic supply places, basically "mufflers" for noisy exhaust ports on air motors, etc; these are a sort of porous metal. Not sure if they'd work for your app but you might see if they're available in corrosion resistant metals.

Stainless wouldn't work - pretty much any plastic would be okay. The etching solution is ferrich chloride which is an acid. I have been trying to think of some ways of making this other then drilling a lot of holes into a pc of tubing and was wondering if some plastic mesh (like mosquito netting) would work rolled up into a tube. There would have to be lots of layers but would this give the effect I'm looking for?

I would like quite a bit of air if possible.

Also - do you think some breathable nylon fabrich would work?

Try one of the white ceramic airstones, available in 1cm diameter (ish) and 4, 6 or 8 inches long. I have used one of these in ammonium persulfate etchant for a few years and it is still OK.

I also find that it gives more, finer bubbles than the cheaper blue sandy ones.

Feeding it from a good pressure pump (I have a small Fisher laboratory pump) makes the etchant foam - works really well and gets into all the gaps. Watch it doesn't foam over the top though.

Rick.

In message , James Varga writes

James, you can buy something like you intended to make from some aquarium shops, it usually comes with little sucker-posts to hold it in place in the aquarium and is about 2 foot in length.

Aquarium shops sell "bubble bar" its a plastic foam pipe perforated to let the air out. I seen it in 6" - 18" lengths

Steve