jewie27:
Why can' t you just RINSE YOUR GEAR WITH FRESH WATER AFTER EVERY DIVE? It will prevent salt buildup.
This sounds like the best advise to me..
What you can clean your regs with really depends upon what they are made from..
Most regs are made from brass (an alloy of zinc and copper mainly) with a chrome plating.
Chrome is largly chemically resistant, though it is listed as soluble in halogen acids, (i.e. hydrochloric acid) and as reactive with sulphuric acid. It should not be exposed to bases (alkalis) or peroxides.
Info from
http://www.intox.org/databank/documents/chemical/chromium/cie547.htm
Copper is very unreactive but zinc is not.
Zinc will react with acids such as hydrochloric acid to form zinc chloride, which is the very corrosion you wish to clean off corroded regs.
The whole purpose of the acid bath is to dissolve any metal salts which may have formed due to corrosion of the zinc in the alloy, but over do it and you will effectively corrode your reg further!
Reaction rate of the metal depends upon the concentration and type of acid used (i.e the pH of the solution) and the temperature of the acid bath.
Vinegar is a weak acid where the protons do not all dissociate, and is in my mind far more suitable than say HCl, which will lead to chloride ions penetrating into the metal, which increaces corrosion rates, despite the fact that some manufactures recommend its use. Chloride ion incursion is responsible for the "brown staining" you see on stainless steel parts at the swimming pool for instance, usually near welds, and it can increase corrosion in steel by something stupid like 400 times!
Non metal parts should not be exposed to acids, bases or solvents as this is likely to weaken them.
On neutralization, baking soda solution followed by repeated fresh water rinsing should do the trick fine, or just the fresh water rinses. Strong bases such as sodium hydroxide should never ever be used!
On isopropy alcohol (propan-2-ol), I wouldn't use it. It has a tendency to form peroxides, unless stabalized, and brass is very very reactive to peroxides. It is not an alkali anyway so it does not neutralize acid, just raises the pH towards neutral by diluting the acid concentration. It will also damage some plastic parts.
If you own an aluminum reg it is protected by a layer of aluminum oxide, this must be kept away from a large number of things including strong acids/bases, halocarbons, (i.e dichlormethane, chloroform 1,1,1 trichlorethane and many other halocarbons found in degreasing agents) and acetone (nail varnish remover). Most of these will happily remove the anodised layer of aluminium oxide and ruin your reg.
Substances like sand need to be removed physically, sand is chemically inert, it doesn't react or dissolve in anything but hydrofluoric acid, which is so strong it would dissolve most of your reg anyhow!
Hope this provides some useful info
Sholto