Caswell Plating

[SteveJ]

Wastewater treatment plants will sometimes specify conformal coating on electronics in the control systems to prevent this from happening.

[Namerow]

Many years ago, I was invited to make an inspection tour of a government research facility (big building, big test rigs).  It was located about a mile away from two steel mills, separated from them by an open harbor.  The facility manager showed me a bunch of expensive electrical panel that he said had been ruined by the SO2 carried in the air from across the harbor.

[240dkw]

I worked in a sour gas plant and there was a story that back in the 80's when it was Gulf they make keepsakes to hand out to the kids during school tour, by pouring molten sulphur into small blocks with the Gulf logo on them. All the kids would take them home and they ended up on top of the family TV or in a china cabinet. Well needless to say the following year Gulf was going around replacing TV's and paying someone to polish all the tarnished silver. 

[Patcon]

3 hours ago, 240dkw said:

I worked in a sour gas plant and there was a story that back in the 80's when it was Gulf they make keepsakes to hand out to the kids during school tour, by pouring molten sulphur into small blocks with the Gulf logo on them. All the kids would take them home and they ended up on top of the family TV or in a china cabinet. Well needless to say the following year Gulf was going around replacing TV's and paying someone to polish all the tarnished silver. 

DOHHHH!!

[Captain Obvious]

10 hours ago, Patcon said:

I thought about seeing if any of my "Sparky" friends wanted to take a shot at repairing it for giggles

I'd be happy to, but honestly, if you actually saw arcing on the PC board, it's probably a goner.  

Was it a real expensive unit?

[Patcon]

The arcing was from a larger vertical cylinder to an adjacent part. I assume that is a capacitor but who knows not my field of expertise. I would be glad to ship it to you for grins and giggles...

The unit is pretty cheap about $65 to $70 shipped...

[Patcon]

Dr.meter

4.2 out of 5 stars 189 Reviews

Dr.meter 30V/5A Single-Output DC Power Supply 110V/220V Switchable with Alligator Clip included, US 3-prong Cable,PS305DM

 

I thread all polished hardware on to 18g brass wire. I found that other materials are unpredictable and left pieces in the same soak dull

 

Then dip in muriatic acid 50/50 distilled water until it quits fizzing.

Rinsed in distilled bucket

 

Per Joe Newsom

 

Let hang into degreaser at 120 degrees until ready usually about 15 min.

Rinsed in distilled bucket

 

Load into zinc tank. Which is constantly heated to 75 degrees with one of submersible heater for fish tank. Loads were calculated to run at 5 amps the max my rectifier will do, for 15 min.

Trying to remember to rotate in middle of load became challenge.

Rinsed in distilled bucket

Dipped into Blue Chromate for about 5-10 seconds

Rinsed in distilled bucket

Dipped into Yellow Chromate for about 15 seconds

Rinsed in distilled bucket

 

Yellow chromate I mixed myself using 10 oz of sodium dichromate which I bought cheaply on eBay and 1 oz sulfuric acid ( battery acid) to one gallon of distilled water.

All other products were bought at Caswell

 

Hope this helps. I really noticed the difference in the properties of the zinc by adding brightener at the beginning of each day I was going to zinc. Noticeably different outcome when I didn’t add it in the beginning of my day.

@joe newsom

So you pickle before you degrease and you wait for the fizzing to stop? I have degreased before pickling and I don't know whether to wait for the fizzing to stop or not. What causes the fizzing?

[Namerow]

I hate anecdotal evidence, but I will say again that the variable with the most pronounced  effect in my plating experience was the regular addition of of the Caswell 'brightener' liquid to my electrolyte bath. 

I don't know why.  I have no formula or explanation to offer.

Alchemy!  Sorcery!

I too want a Caswell franchise where I can sell overpriced, unexplained chemicals to optimists just like me.

[joe newsom]

 
Here is power supply
 
Dr.meter
4.2 out of 5 stars 189 Reviews
Dr.meter 30V/5A Single-Output DC Power Supply 110V/220V Switchable with Alligator Clip included, US 3-prong Cable,PS305DM
 
I thread all polished hardware on to 18g brass wire. I found that other materials are unpredictable and left pieces in the same soak dull
 
Then dip in muriatic acid 50/50 distilled water until it quits fizzing.
Rinsed in distilled bucket
 
Let hang into degreaser at 120 degrees until ready usually about 15 min.
Rinsed in distilled bucket
 
Load into zinc tank. Which is constantly heated to 75 degrees with one of submersible heater for fish tank. Loads were calculated to run at 5 amps the max my rectifier will do, for 15 min.
Trying to remember to rotate in middle of load became challenge.
Rinsed in distilled bucket
Dipped into Blue Chromate for about 5-10 seconds
Rinsed in distilled bucket
Dipped into Yellow Chromate for about 15 seconds
Rinsed in distilled bucket
 
Yellow chromate I mixed myself using 10 oz of sodium dichromate which I bought cheaply on eBay and 1 oz sulfuric acid ( battery acid) to one gallon of distilled water.
All other products were bought at Caswell
 
Hope this helps. I really noticed the difference in the properties of the zinc by adding brightener at the beginning of each day I was going to zinc. Noticeably different outcome when I didn’t add it in the beginning of my day.
 

Here are some pics of the set up. It is not much to let look at but it works for me.


Sent from my iPhone using Classic Zcar Club mobile

[Patcon]

@joe newsom

Now if we could just figure out a DIY for the Blue Chromate. It is pretty expensive and  would allow for a larger dipping tank...

[Namerow]

22 hours ago, joe newsom said:

Loads were calculated to run at 5 amps the max my rectifier will do, for 15 min.

Good write-up.  Thanks for taking the time. 

Not much difference in your methodology vs. mine, except for four things:

• Use of brass wire:
  
  Your comment about this making a difference is intriguing (although not intriguing enough to make me drag out all my chemicals to try it out).  It would seem to be a matter of net conductivity at the contact point(s) between the wire and the part.  I used copper wire (should be better  than brass).  Not sure that it was a determining factor in the quality of my plating, but seem to have observed a difference with brass vs. 'other' (steel?).
   
• Batched jobs
  
  I had miserable luck trying to plate multiple pieces at once.  Too much difference from one part to another, so lack of reliable way to control for best net result.  I adopted an approach of max. 2 parts at a time.  Took forever, of course.
   
• Current setting
  
  Many detailed write-ups on zinc plating specify a current setting based on the immersed surface area of the part(s) being plated.  Current set to high = fluffy/flaking zinc over-deposit on the part.  Current set too low = long plating times or minimal plating activity.  I have a notepad full of surface area calculations.  You seem to have gotten away with a 'let 'er rip' approach, by just cranking your power supply up to max and putting as many parts as will comfortably fit on your wire.  Is so, I am in awe.
   
• Yellow chromate
  
  I used Caswell's stuff.  Your DIY formula is interesting, but I don't think the yellow chromate dip is the determining factor in the end result.  Nor the blue chromate dip.  Instead, it's the quality of the zinc plating job that, in my experience, determines the quality of the final finish.  The chromate dips embellish a good zinc plating job, but they won't rescue a badly plated part.  In fact, they just exaggerate any deficiencies.
   
• Zinc
  
  I used 'MossBoss' roof flashing.  It's an uncoated, thick zinc foil.  I lined my electrolyte bucket with it.  Although not shown in your photos, it appears that you used Caswell's zinc plate and hung it on one side of your bucket.  In theory (emphasis on 'theory'), my approach should be better because it reduces the directional effect.

Things we've done the same:

• muriatic acid dip
• distilled water dip between every stage of the process
• Caswell chemicals for the electrolyte bath
• Caswell brightener added on a regular basis (with notable effect)
• heated degreaser bath (I used an ammonia/water/TSP solution in a crock pot -- I think you used the Caswell stuff)
• heated electrolyte bath (I think I ran mine a bit hotter than yours... maybe 100 degrees F)
• size of electrolyte tank (mine bucket might be about 10% smaller in depth and diameter)

 

The main things I had problem with were:

• hyper-sensitivity of end results to the prep and cleaning of the parts.  Once a part displayed a 'flaw' after initial plating, I had to take it right back to the sandblasting stage to get rid of the problem.  Wire-wheeling and acid-dipping wouldn't get rid of it.
   
• irregular plating over large surfaces (e.g. timing chain inspection cover) and parts with bends (e.g. brake line clips)
   
• inability to get satisfactory results when trying to plate multiple parts in on go

Edited November 9, 2017 by Namerow

[Captain Obvious]

I don't know anything about plating other than it's one of the black arts and I suspect that small seemingly immaterial details might not be so immaterial. For example:

About brass vs. copper wire: Was the copper wire nickel plated, or bare? Who knows what nickel would do in the mix...
Also, since brass contains zinc, maybe the localized zinc source helps prevent marks where the wire was? (As opposed to high purity copper with no zinc)

About the sacrificial zinc anode: I couldn't find details on just how pure Caswell's zinc plate is, but I did find an MSDS for Moss Boss that says it could be as low as 98% zinc and as high as 2% copper. Who knows what copper would do in the mix on the plate... MSDS here:
https://www.menards.com/msds/103923_001.pdf

Just musing...