Homebrew PCBs

Hi guys,

Does anyone know off-hand what the required ratio of Hydrochloric Acid 
to Peroxide is when starting off a cupric chloride etch bath?

I've tracked down these 'starter' chemicals on ebay:
   HCl: 
http://cgi.ebay.co.uk/BRICK-CLEANER-CEMENT-REMOVER-CONCRETE-REMOVER-ACID-/250631108343?pt=LH_DefaultDomain_3&hash=item3a5ac736f7
    or 
http://cgi.ebay.co.uk/Disclean-Brick-Cleaner-2-x-5lts-/390122417591?pt=LH_DefaultDomain_3&hash=item5ad51badb7

   H2O2: 
http://cgi.ebay.co.uk/2x200ML-Bell-Hydrogen-Peroxide-9-Anti-Septic-Bacterial-/130392225994?pt=UK_Health_HealthCare_RL&hash=item1e5bfb78ca

This is 17.5% strength HCl, and 9% H2O2. Assuming this is strong enough 
to start a cupric chloride bath (with a sufficient amount of air and 
scrap copper provided), what sort of mix ratio would I need to make a 
viable etchant?

Do I need to target a specific pH? That is, do I need to buy litmus 
paper and so on too?

What about titration and specific gravity control -- is that necessary? 
I have some sodium hydroxide granules in the cupboard (CIF Photoresist 
Developer; I've been using MEGA CPD5 instead because it's less harmful 
and harder to screw up), but would need to hunt down a suitable 
indicator chemical and glassware...

Thanks,
-- 
Phil.
ygroups@...
http://www.philpem.me.uk/