DIY Crappy Zinc Plate!

[Dreef1999]

So having been slightly immobile for the past couple weeks with a hurt back I made a little science experiment to keep myself busy. I wanted to see what zinc plating was all about.

I read that you need a solution of
Ammonium Chloride 120 grams
Zinc Chloride 20-30 grams
~1000 grams of H20

Now to get from the hardware store to here you will need Hydrochloric Acid(murietic acid) mine was 14.5% for $10, Ammonia janitor strength(should be 10%) for $3, and a zinc anode from a boat shop.




To review the chemistry
HCl+NH4OH => NH4CL (ammonium chloride) + H2O
2HCl+Zn => ZnCl2 + H2

Some molar weights
Metalic Zinc 65.38g/mol
Ammonia 17.036g/mol
HCl 36.46g/mol
Ammonium Chloride 53.49g/mol
Zinc Chloride 136.315g/mol

I had 10% ammonia, 14.5% acid, and zinc metal
I did everything by weight and assumed the HCl and Ammonia concentration was by weight.

I mixed 140grams of ammonia(10%) with 206.7grams of HCl(14.5%) in a safe glass container. If your percentages are different you will have to change your amounts.

I then measured out 7.84grams of HCl and placed the zinc in over night. Let it sit for a long time and if there is leftover zinc then the reaction should be complete.

Mix the ammonium chloride solution with the zinc chloride and you have a functional zinc plating bath. Place your zinc anode into the bath connected to the (+) end of your power supply or battery (if you are using copper wires don't let the copper wire touch the liquid), hook the item to be plated on the (-) side of the power and place it into the bath.

It should plate but it will probably look crappy. There is a lot of fine tuning to get a good plate and the power source is one of the biggest issues. Additionally the kits have proprietary brighteners which may or may not work in this homebrew solution. I am far from an expert so maybe somebody with some more technical knowledge knows better how to get good results.

I figure this is good enough for rust protection only and for $20 in material costs I am not dissapointed. I have been working on some pennies to experiment so far but I don't think I have had my DC current even remotely close to correct yet.

[Nessism]

I like your line of thinking here.

I recently purchased a zinc plating kit from Caswell Platting and it's been keeping me busy. Researched making up my own kit using this as a guide http://cb750k2.tripod.com/Technical/plating.html but chemistry was never my best subject and the needed chemicals didn't seem to be commonly available.

It's taken me a while to get the feel of the Caswell kit but I'm digg'n it now. Did some bits with the yellow cromate finish this weekend and they turned out great.

Keep up the good work and post some more photos and ideas on your setup. I used a 12V battery and/or battery chargers to push the ions. Have a surplus computer power supply I'm going to adapt at some point but so far the battery is working fine. Here is a thread I posted a while back showing my setup... http://www.thegsresources.com/_forum...d.php?t=144575

[Dreef1999]

I like your line of thinking here.

I recently purchased a zinc plating kit from Caswell Platting and it's been keeping me busy. Researched making up my own kit using this as a guide http://cb750k2.tripod.com/Technical/plating.html but chemistry was never my best subject and the needed chemicals didn't seem to be commonly available.

Yeah! I found that guide too and it was pretty daunting at first. But it wasn't too hard to get to the end product with the HCl and ammonia.
Plus I have enough materials to make 2 more gallons of solution if I want to.

But, the results your kit are giving are lightyears beyond what I am getting right now. I think I have been 'burning' all of my pennies so far and I need much better current control before I can really accomplish anything. A 1.5v D battery is plating a penny in just a couple minutes and I think I read on the caswell site that it takes 10-20 minutes to get a good plate.

[Dreef1999]

Ok big improvements.
First I mixed a new batch with 1/3 less zinc-chloride(now 20g ZnCl2 and 120g NH4Cl)
Acid Dip in 14.5% HCl for 5 minutes minimum.
Tap rinse and dish soap clean
Designate some pliers, tweezers, forceps, or have gloves to touch(gotta keep it clean)
Acetone rinse clip/wire too
Clean Water Rinse

Straight into the Solution.
2 Pennies at once plate pretty respectably off one D battery. (~1.5v at ~1.6amps/in^2
Light polish and it is reasonably shiny.

Too much power and you get a very rough plate that is an interesting white. More appropriate cleaning made a huuuuge difference in the plating as well as getting the power much closer to the target.