Caswell Plating

[motorman7]

5 minutes ago, Patcon said:

So you are using a good bit of brightener!? How much liquid in your plating tank?

5 gallon bucket with about 4 gallons of liquid.

[Namerow]

On 9/5/2017 at 6:24 PM, Patcon said:

Did you ever finish all your plating?

Hah! That depends on your definition of 'finished'.   I completed everything I wanted to do, with the exception of the my hood prop rod.  I bought a replacement prop rod from Zkars and it arrived after I'd put the chemicals away and after I'd given Grannyknot back his controllable power supply (which I suspect he figured he'd never see again -- Chris a remarkably generous, patient, and polite guy).  Some observations from my electroplating experience:

• To anyone just getting started on a plating project, I recommend you ignore all the 'budget' plating articles you'll find on the internet.  I spent so much time and money experimenting with these DIY, low-buck recommendations (epsom salts, corn syrup, vinegar, etc.) that I would have been better off spending $500 to get a commercial outfit to do the work for me.  If you really want to do it yourself, just hold your nose and buy the (premium-priced) Caswell chemicals.  They work pretty well, for the most part.
   
• Even with the Caswell chemicals, there's a lot of trial and error involved.  To get a good end result, everything needs to be right and there's zero tolerance for parts that haven't been properly cleaned and prepped. 
   
• I hindsight, I don't think electroplating scales down well to the 'hobbyist' level.  Or to put it another way, I suspect that, 'The bigger the vat and the heftier the power supply, the better the result'.
  

• I had mixed results trying to do multiple small pieces at the same time.  This just seems to increase the chances for error.
   

• The 'Mount Everest' for my S30 plating project was getting a good result for the two-piece engine inspection light housing.  With it hollow configuration and welded-on mounting bracket, it's hard to get complete, even plating coverage over the outer surfaces.  It took me two tries to get a result that I was (sort of) happy with.

  
   
• Plating longer pieces (like the hood prop rod or the rear engine coolant transfer tube) will force you to buy a double-quantity of the Ca$well chemicals in order to get a bath volume big enough to plate these pieces in one shot.
   
• I don't think I'd try this job again without a controllable-voltage/current power supply (add $100 - $150 to your budget).  I tried using a fixed-voltage power supply to start (I used a daisy-chain of automotive 12V bulbs to control the current), but it was a PIA and the results weren't very good either.
   
• I remain a little concerned about the durability of the yellow chromate finish on my parts.  On some pieces, it would wipe right off.  Some people suggest that the parts have to be baked in an oven after plating.  Maybe this 'locks down' the chromate?
   
• I'm thinking about trying a two-stage powder coat as an alternative to yellow zinc plating.  There are some pretty interesting 'glaze' top coats available these days.

 

[Patcon]

I bought a 10 amp CC/CV variable power supply for about $75.

I agree the window for good results seems to be kind of small. It can also be hard to figure out how to adjust the process based on results to get to where you want to be...

[Namerow]

1 hour ago, Patcon said:

I bought a 10 amp CC/CV variable power supply for about $75.

I agree the window for good results seems to be kind of small. It can also be hard to figure out how to adjust the process based on results to get to where you want to be...

Non-chemists messing with chemistry = alchemy

As an engineer, I hate 'hit-and-miss' when I know that science offers a better solution.  Unfortunately, I'm not a chemical engineer

[Patcon]

On 9/7/2017 at 8:23 PM, Namerow said:

Non-chemists messing with chemistry = alchemy

As an engineer, I hate 'hit-and-miss' when I know that science offers a better solution.  Unfortunately, I'm not a chemical engineer

I totally understand and agree!

My wife and her best friend are both chemist, but that still hasn't help me get repeatable results. It can't be as hard as I'm making it or commercial plating would be far more costly.

Edited October 1, 2017 by Patcon

[Patcon]

So here is what I've got so far. I filtered my plaiting tank with a bunch of coffee filters stacked onto of each other on some metal window screen. Sort of hard to do efficiently. I had some brown particles that had settled out on the bottom of the tank but they are fine enough to go through the coffee filters. I spoke to Caswell tech and they said that was ok and when the bath was running it should be cloudy. So that is ok.

The Ph on the plating tank at 4 is too low and can cause the starter chemical to be removed from solution. Too high and the Zinc can precipitate out. You use Ammonium Hydroxide (plain household ammonia) to raise the Ph. I added about 40+ tablespoons to raise my 3 1/2 gallon plating tank about 1 - 1.5 points. Initially, I was concerned I had raised it too high but once I got it mixing and heated up it settled in at about 5.5. I assume my plating tank has been lowered because of the pickle tank I use before the plating tank. Evidently I am not getting all the acid rinsed off the parts and it had lowered the tank Ph. Caswell said I should use a baking soda neutralization after the pickle. I would then have to rinse that. I may just come up with a better rinse method after the pickle tank...

I have some new strut caps that came with the new struts but they didn't look very good. They may even be raw metal, so I decided to use them as test subjects.

I bead blasted both and put them in SP degreaser, thanks Rich for that. I was able to clean the hard crystal out of the crock pot eventually...

I didn't pickle the first part and I checked it for being clean with a water test. Plated it at 1.2A for about 30 minutes. Rotating it about every ten minutes. I also added a tablespoon of brightener to the tank as Caswell thought this was why the plate was dull.

Much better results except for one spot on the first part. I did them one at a time and I strung them on a loop of wire through the center. The mark is a dark stain almost like an oil spot but it was right under where the loop was contacting the part...

Even after I rotated the part away from the wire and plated it some more it didn't go away. I wrote this is off to the overly quick prep work

I did a 60 second blue dip and a 60 second yellow dip. Dried it on low with the heat gun. Did good overall except for the spot which didn't take any color...

 

I ran the second part but I pickled it for a minute or too with no real bubbling. Then plated it the same way. I got a similar spot under where the wire was sitting on the part???? Has anyone seen this happen before ?? @motorman7 @Namerow

This is the finished part after color

So Here are my guesses:

1. Contaminate on the wires I am using

2. Burned the part where the wire met it

3. Didn't plate where the wire met it

4. Contaminate on both parts and coincidentally lined up with both plating wires

5: Plating wire is too small for the amperage

My gut instinct is #1,2 or 4. It seemed like the wire made a secondary mark on the first part where the wire was hanging the second time (The dark stain at 2 O'clock by the weld in the first picture)

Anyone else have any thoughts or solutions?

[Namerow]

I wonder if the wire is acting like an electromagnetic cage, so that it sets up some kind of adverse electrical field in the zone where you get the dull spot?  You'll probably say, 'Why don't I get the same effect when I plate a regular flat washer?'  My guess is that this particular part is 'deep' enough in section that it shows some of the plating characteristics of a hollow tube.  If you're still feeling 'experimental', try this:

Sandblast one of the two parts to take it back to bare metal (hopefully, this will get rid of any residual problems in the dull-plating zone).  Now try a centralized supporting system for the part when it's in the plating bath.  I'm thinking you could take a length of wire and wind it into a coil that's about 10% bigger than the ID of the centre hole in the strut cap.  The idea would be for the wire coil to be under enough compression when you put it in the hole so that it will grab the part.  This is just a WAG... but that's what drives scientific investigation sometimes.

(When you enter the world of DIY plating, I figure you deserve to call yourself a scientist.  It sounds a lot more confident that 'wizard' )

[grannyknot]

How about winding the wire tightly around the threads leaving the face/top free and clear?

[Patcon]

Thanks guys. I had both of those as ideas, but wasn't sure. I thought about taking the parts back to bare metal and try them again. As  they make a good "control" at this point. I thought I would clean the support wire and suspending them differently.

I personally like the sound of "Wizard!"; much more impressive!!

[Patcon]

Well I tried to work on these strut caps some more. Prepped them and was ready to plate. Cut the power source on and it sparked and blew out the fuse. On closer examination it had a lot of condensate on it. Took it in the shop cleaned it up. Opened it up, checked it over and replaced the fuse and it did it again. Saw it arc on the board. So the lesson here is to not store this outside or near the chemicals for extended periods. I suspect the acid fumes damaged the board, so I ordered a new power supply today...

[Namerow]

Uh-oh. I hope it's not the sulphuric/muriatic acid you may have been using as a pickling agent.  I've read that that the fumes from that stuff can be corrosive to equipment and tools if stored indoors.

[Patcon]

14 hours ago, Namerow said:

Uh-oh. I hope it's not the sulphuric/muriatic acid you may have been using as a pickling agent.  I've read that that the fumes from that stuff can be corrosive to equipment and tools if stored indoors.

My plating bench is under a covered roof outside my shop.I keep the bench outside because I didn't want the fumes in my shop. I keep it covered in plastic to keep dirt and sawdust off of it. The power supply sits between the SP degreaser and the pickle tank. So right next door, like 4". I suspect the fumes from all of the solutions can move around under the plastic. All of the chromate solutions have very low Ph's too. The new one will be set out and removed for every plating session

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

@Captain Obvious @SteveJ