? etch ?

[LightSoundGeometry]

What is the purpose, if any at all, for the blocks?

how does agitating the etchent help strip the copper?

[Vitrolin]

what blocks???

when agitating the etchant you add more oxygen from the air, the oxygen itself is an etchant and present in all acids,thats why a air pump is the best way to agitate your etchant.
i'm no expert in chemistry but pretty shure thats the way it works from what i remember from school, though it was alot of years ago...

[karbomusic]

how does agitating the etchent help strip the copper?

The byproduct of the etchant/copper ends up blocking the fresh etchant. In fact, if you rub it with a sponge you can take the etch time down to a couple minutes - literally. You can also see this if you look closely, it's the black stuff floating close to the board.

[Pettol]

I agree with karbomusic. In principle.
Chemical reactions normally gain from agitation. It increases speed by introducing "mixing entropy". A car would rust much more quickly if you could stirr it. 

[duck_arse]

you put the board on blocks so's you can steal the wheels, natch.

the blocks under the board in the etch tank will allow the spent junk etchant to drift to the bottom as you agitate, instead of just building up thick on the etching surface. a bubble tank stands the board vertical, and the bad stuff just sloughs off with the bubbles providing all the agitation and convection needed.

[LightSoundGeometry]

I observed faster and harder agitation increases the etch process exponentially ..within minutes as mentioned above.

I was wondering if Small Bear has a recommended solder tip for PCB and Perfing projects ? I am using a WP30 gun or a WES51 and always get the wrong tips for the job.

also, I seem to have gotten fake/bad tips from ebay ..you can just tell once using a tip if its a real weller or not ..the fake ones do not last and the real wellers never die ..my original tip is still on my gun as compared to a cheap tip that last about 1-2 projects and barely works!

http://smallbear-electronics.mybigcommerce.com/soldering-1/