Caswell Plating

[Patcon]

Thanks,

I agree the process doesn't tolerate contaminants. I have looked for MossBoss, it doesn't look like it will be a problem to source on this side of the border. How thick is Moss Boss?

[Namerow]

29 minutes ago, Patcon said:

How thick is Moss Boss?

Rough guess:  1/64" / 0.025"

[Patcon]

9 minutes ago, Namerow said:

Rough guess:  1/64" / 0.025"

Thanks

[Patcon]

So I did a lot of plating. Mostly little carb pieces and such. Got pretty good results.

I found a source for zinc. I bought a 12x12 plate from Fisher Science. I cut it in half and made 2 large anodes.

I folded some tabs on the plate, but I beat them flat, which is a mistake. The zinc is so brittle the tabs will just crack off

Then I started on the line insulator pieces. That didn't go so well...

By the way is this line bracket 280z specific?

so I backed up and was figuring I was having a connection issue at the part. The hanging wires were plating beautifully

T

Those are both raw zinc, no chromate

So I took 4 pieces all the same and wired them all differently. 2 with heavy wire and 2 with lighter wire

I degreased them and put them in the pickle until they quit bubbling..

Then I plated all 4 in the tank at the same time. I rechecked my areas and plated at 0.14 amps/inch

The one on the far left had a heavy wire tied top and bottom and it did the best. Second best was the other heavy wire 3rd from the left. Then the two lighter wires.

I am emailing with Caswell and got this advise:

After plating, try dipping in a very weak muriatic acid dip, about 2 seconds, then rinse and dip again in rubbing alcohol for 5 seconds, rinse and go in to the chromate. Let me know if that helps

I will try that, but these results seem to suggest a connection problem and maybe a not enough current. Thoughts?

 

Edited December 31, 2017 by Patcon

[Patcon]

I also had some issues with this carb shaft. I was getting what I thought was heavy shadowing. So I reran it...

Now it is entirely possible I didn't get it clean enough. So I bead blasted it again and degreased and hung it so as to expose these areas better to the plates. This is what I got.

It came out really good.

As an aside I had this piece not turn out. Evidently after bead blasting there was no circuit into the swivel part of the choke linkage. The bar plated but not the connection.

I stripped it and when I restrung it I added a wire through the barrel and it came out fine...

[grannyknot]

1 hour ago, Patcon said:

After plating, try dipping in a very weak muriatic acid dip, about 2 seconds, then rinse and dip again in rubbing alcohol for 5 seconds, rinse and go in to the chromate. Let me know if that helps

Are they saying the rubbing alcohol is alkaline enough to neutralize the muriatic acid?

[Patcon]

8 hours ago, grannyknot said:

Are they saying the rubbing alcohol is alkaline enough to neutralize the muriatic acid?

I don't know. The only time I have seen someone use alcohol was to dry the part at the end of the process

 

[nix240z]

are you using  circulation pumps in your bath? 

[240260280]

Physics: 

1. Charged particles take the shortest path  (thus the shadowing effect).

2. Charge intensity varies across non-uniform surfaces.

3. Charge is stronger at edges/points (related to #2 above).

 

FYI: By using a rolling drum in a bath, the parts move randomly and the charge intensity on the part surfaces is always changing so there is less shadowing effect and less edge effect.

 

A rectangular bath solution with a stationary part could be optimized by:

• 2 zinc plates running  end to end and crossing in the middle bottom then running up the walls.
• The power supply output would connect to the middle of each side/plate (split it 4 ways).
• The part to be plated (if big and odd shaped like the throttle shaft) would need two or more wires connected to it and turned occasionally
• As Nix says, a circulation of the electrolytic will also redistribute the zinc ions so there are no pockets of depleted solution. An alternative to this would be to move the part in the bath. A string connected to a  disc on a motor  could lift the part up and down within the solution (or it could lift one side of the hanging rod). Some use an aquarium bubbler to mix the solution.

 

[Patcon]

3 hours ago, nix240z said:

are you using  circulation pumps in your bath? 

Yes, I am using a submerged aquarium pump. Although it could be possible I need more agitation, but the surface of the liquid does move

3 hours ago, 240260280 said:

Physics: 

1. Charged particles take the shortest path  (thus the shadowing effect).

2. Charge intensity varies across non-uniform surfaces.

3. Charge is stronger at edges/points (related to #2 above).

 

FYI: By using a rolling drum in a bath, the parts move randomly and the charge intensity on the part surfaces is always changing so there is less shadowing effect and less edge effect.

 

A rectangular bath solution with a stationary part could be optimized by:

• 2 zinc plates running  end to end and crossing in the middle bottom then running up the walls.
• The power supply output would connect to the middle of each side/plate (split it 4 ways).
• The part to be plated (if big and odd shaped like the throttle shaft) would need two or more wires connected to it and turned occasionally
• As Nix says, a circulation of the electrolytic will also redistribute the zinc ions so there are no pockets of depleted solution. An alternative to this would be to move the part in the bath. A string connected to a  disc on a motor  could lift the part up and down within the solution (or it could lift one side of the hanging rod). Some use an aquarium bubbler to mix the solution.

 

That is all good info. Would more current reduce the edge highlighting effect?

My tank is a 5 gallon bucket with two 6" wide plates extended all the way to the bottom on opposite sides.

I may eventually make a plating barrel, but it will have to wait for the next car. There were a couple of threads on the Caswell forum that mentioned getting almost a chrome look from a plating barrel but being unable to get it when hanging parts.

The centers of those parts basically look unplated. That is why they didn't chromate....

[nix240z]

I use 2 circulation pumps from harbor freight  in my 5 gallon bath.  Get the flow right on the parts being plated. I turn the parts every 5 minutes. 

[Patcon]

2 hours ago, nix240z said:

I use 2 circulation pumps from harbor freight  in my 5 gallon bath.  Get the flow right on the parts being plated. I turn the parts every 5 minutes. 

Thanks Steve

I will look into another one