Caswell Plating

[Namerow]

I'm afraid I'm going to have to go metric on you here:

• 100 grams of epsom salts for every 1 litre of vinegar. 

In your terms, that would be 3.53 oz (by weight) of epsom salts for every 1.06 US gallons of vinegar.

Ignore anything you read about adding sugar, saccharine or corn syrup to the bath to act as a brightener.  There are a number of reports that this achieves very little in the way of brightening and can end up creating a sticky mess.

 

I bought some very handy graduated mixing tubs (clear plastic) from the hardware store.  They hold 2 litres of liquid (0.53 US gallons).  Using these, I discovered that my '2 kg' (by weight) container of epsom salts measured out at 1700 millilitres (by volume).  I am using 16 litres of vinegar (4.2 US gallons), so I needed 1600 gm (by weight) of salt.  Using my weight-to-volume conversion factor of 1700/2000, that meant I needed to measure out 1360 mL of salt (46 US fl.oz.) to add to the bath. 

Using fluid volume measures, the mixing ratio is therefore:

• 1360 mL of salt for 16000 mL of vinegar

or,

• 1 fl.oz. salt to 11.76 fl.oz vinegar  (i.e. 1 measure salt for every 11.76 measures vinegar)

You'll probably be using 4 US gallons of vinegar (4 x 128 = 512 US fl.oz.).  That means you'll need to add 43.5 fl.oz. of salt. (512 divided by 11.76).  If you get the same volume-to-weight conversion that I did, the 43.5 fl.oz. volume of salt would weigh 51.2 ounces, or 3.2 lb.

Be sure to check my math before doing your purchasing and mixing.

I'm now using just a single, 4"-wide hoop of 'Moss Boss' zinc foil in my 5-gallon pail.  The inside wall of the pail has a slight draft angle, so I lap-soldered the zinc strip to create a hoop of just the right diameter to lodge about half-way down in the bath.  The pail measures about 10.5" in diameter at that point, so that means I have about 130 sq.in. of exposed zinc inside the bath (i.e. just shy of 1 sq.ft.).  I soldered 12" lengths of solid copper wire at the '9' and '3' positions on the hoop and use these as my connector terminals for the 'POS' lead of the power supply.  They also give me a hand hold that I can use to pull the zinc hoop out of the bath between plating sessions.

 

[Patcon]

Thanks,

The metric is fine and I will check it before I change it out. I have lots of buckets from customers jobs so I will be using 5 gallon buckets. Any particular vinegar? Just white vinegar?

[Namerow]

36 minutes ago, Patcon said:

Thanks,

The metric is fine and I will check it before I change it out. I have lots of buckets from customers jobs so I will be using 5 gallon buckets. Any particular vinegar? Just white vinegar?

Plain old white vinegar.  Ignore the extra-strength 'cleaning' version. I have no idea what they do to make it extra-strength, but it undoubtedly will involve a different pH level.  No sense in adding a new unknown to a process that's already challenging .

[Patcon]

So in between tearing down the diesel I am working on I took a shot at plating again. Before I started and while everything was heating up I worked on my plates. They were black and crusty and I left them overnight in the solution. I assume that was a mistake....So I started with this and wire brushed them and then sanded them smooth

I got the plating solution up to about 120F. The directions for my new power supply say to turn the voltage all the way up and the current all the way down and not to turn it off or on while connected to a load. So you cut it on and short the leads to each other and adjust the current dials until the current is at the level you want.

so I started with these 5" pipes again. The first was run in the tumbler overnight. 15 minutes of plate / rinse / 90 seconds of chromate / rinse

 

Thought the zinc would be a little brighter not so flat grey....

 

The focus is off for some reason. The one on the left is the one from the tumbler. the one on the right was buffed on the buffing wheel. Very shiny before plating. It came out much better...I ran the second one for 120 seconds in chromate.

On the second piece the bottom started to burn or turn black from something. Any ideas?

This is the fourth piece and has a little flash rust around one of the holes. I thought I would try it for fun

This is how it came out all finished...

SP degreaser hot / rinse / acid dip for 20 seconds / rinse / plate for 20 minutes / rinse / chromate for 2 minutes

Not very noticeable but still there

Did this one too but there were areas where the texture wasn't smooth and it sort of looks like pits with zinc in them but they didn't yellow with the chromate

I came up with pretty good color. Still have to work on the finishing before plating. I need to come up with a good solution to make them smooth. If the finish was smooth enough I could get the color pretty good.

One issue I ran into was after chromating I rinsed it and some of the chromate rinsed off along the edges where the finish was smoothing. Has anyone else seen this?

This is how the plates finished. Does the black affect plating? What do your guys plates look like?

[nix240z]

Too much power (IE: current)  will cause black plates and a rough finish on the part. 

Remember you will have to do a lot of trial and error to figure out what will work for your setup.

.

[Namerow]

10 hours ago, nix240z said:

 

 

Edited June 12, 2016 by Namerow

[Namerow]

10 hours ago, nix240z said:

Too much power (IE: current)  will cause black plates and a rough finish on the part. 

Remember you will have to do a lot of trial and error to figure out what will work for your setup.

.

.Are you saying that the zinc anode plate will/should retain a shiny appearance under ideal current conditions?

[Patcon]

The finish on the part seems pretty good. No rough looking at all at least if the part is smooth. I was wondering if the black could be contaminants in the plating solution...

[Patcon]

Found the threads on Black anodes

http://forum.caswellplating.com/forum/electroplating-questions/15358-black-marks-on-finished-zinc-plated-item

 

http://forum.caswellplating.com/forum/electroplating-questions/7741-zinc-anodes-turning-black

apparently not an issue.

On another note is anyone here using the blue chromate prior to yellow chromate?

[Patcon]

I think I made some real progress on this last weekend. I will try to do some samples and make some good pictures and I will elaborate on my technique...

[Namerow]

11 hours ago, Patcon said:

I think I made some real progress on this last weekend. I will try to do some samples and make some good pictures and I will elaborate on my technique...

Looking forward to your latest notes.  I'm still not getting the results I'd like.

[Patcon]

12 minutes ago, Namerow said:

Looking forward to your latest notes.  I'm still not getting the results I'd like.

I may have found a solution for you...