Full Gold tracks?

[carasoph]

Hiya all,

After having the same issues with numerous cards, I've done some experiments with the ratios of water+Sodium Hyroxide and I the best results came from this one...

4 Galons of Tap water, warmed to around 122F.
Add 1Lb of Sodium Hydroxide and stir to dissolve...
NOW - here is the tricky part - the water are already WARM...so be EXTRA careful here - the almost reach the boil point in a matter of SECONDS!!!!!!! be sure you wear FULL protection gear (gloves, long sleeves and goggles).
As soon as the SH dissolve - toss the cards inside for 6-12 hours, depending on the ammount.
Rinse with water to clean - it usually needs nothing more the just the water to remove the mask off...

Hope this helps...

 

[SilverFox]

After looking at this... It almost seams safer to eat crushed glass.

Hazards Identification

Emergency Overview
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WARNING! HARMFUL IF SWALLOWED, INHALED OR ABSORBED THROUGH SKIN. AFFECTS CENTRAL NERVOUS SYSTEM, LIVER, CARDIOVASCULAR SYSTEM, AND BLOOD. CAUSES IRRITATION TO SKIN, EYES AND RESPIRATORY TRACT. SUSPECT CANCER HAZARD. MAY CAUSE CANCER. Risk of cancer depends on level and duration of exposure.

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Health Rating: 3 - Severe (Cancer Causing)
Flammability Rating: 1 - Slight
Reactivity Rating: 2 - Moderate
Contact Rating: 3 - Severe
Lab Protective Equip: GOGGLES & SHIELD; LAB COAT & APRON; VENT HOOD; PROPER GLOVES
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Inhalation:
Causes irritation to respiratory tract. Has a strong narcotic effect with symptoms of mental confusion, light-headedness, fatigue, nausea, vomiting and headache. Causes formation of carbon monoxide in blood which affects cardiovascular system and central nervous system. Continued exposure may cause increased light-headedness, staggering, unconsciousness, and even death. Exposure may make the symptoms of angina (chest pains) worse.
Ingestion:
May cause irritation of the gastrointestinal tract with vomiting. If vomiting results in aspiration, chemical pneumonia could follow. Absorption through gastrointestinal tract may produce symptoms of central nervous system depression ranging from light headedness to unconsciousness.
Skin Contact:
Causes irritation, redness and pain. Prolonged contact can cause burns. Liquid degreases the skin. May be absorbed through skin.
Eye Contact:
Vapors can cause eye irritation. Contact can produce pain, inflammation and temporal eye damage.
Chronic Exposure:
Can cause headache, mental confusion, depression, liver effects, kidney effects, bronchitis, loss of appetite, nausea, lack of balance, and visual disturbances. Can cause dermatitis upon prolonged skin contact. Methylene chloride may cause cancer in humans.
Aggravation of Pre-existing Conditions:
Persons with pre-existing skin disorders, eye problems, impaired liver, kidney, respiratory or cardiovascular function may be more susceptible to the effects of this substance.

 

[rainmaker]

I have several questions on the use of Sodium Hydroxide to remove soldier mask.

How do you dispose of it?

Does it need to be neutralized?

How do you know when it becomes ineffective/and or needs to be renewed/replaced?

I have used it in the crockpot and after several batches of boards it is now a clear brown with a layer of sludge/mask pieces.

Rainmaker

 

[goldsilverpro]

If you were to hammermill the boards to about 1/2", you may be able to leach with something that would dissolve both the copper and the gold - HCl/bleach? - HCl/strong H2O2? The hammermill would really gnarl the pieces and expose a lot of copper edges to the acid. It may take awhile for the acid to get underneath the mask. You could speed it up by pouring the acid out and back, every so often, by applying some heat, or by attaching a hopper vibrator to the bucket - or, all 3. I have tried the vibrator for another application and it worked great. Wood shredder/chipper?

Of course, you could dip the boards in liquid nitrogen, right before you hammermill them. You might end up with gold plated copper, solder, and resin/glass powder. Maybe you could pan off (or, blow off) the powder.

Just thinking out loud.