Caswell Plating

[Patcon]

Thanks,

That is a good method to start with...

C

[240260280z]

I have a batch of very weak nitric acid to be used for a final dip to brighten the part. I have not started plating yet but I did a lot of reading and it seemed to be a useful final step.

I did crude plating a few years back and it worked fine but the finish was dull.

Edited April 14, 2015 by Blue

[Patcon]

This was a neat site that somebody made about their plating. There is a barrel plater setup here which is really neat and seems to work really good. Notice the 240z parts in the gallery...

 

http://www.nulltime.com/zincplating/site_map.html

[Patcon]

Here's one other thread and a site someone else setup...

 

http://www.lainefamily.com/CaswellPlating.htm

 

http://ferrarichat.com/forum/boxers-tr-m/373912-diy-zinc-cad-lookalike-plating.html

[Patcon]

This was interesting if you really want to DIY

 

http://thefactoryfiveforum.com/showthread.php?14392-DIY-Zinc-Plating-for-Donor-Nuts-and-Bolts

[Namerow]

I've built a DIY zinc plating setup similar to the ones discussed in the Factory Five link.  Used zinc-strip roofing peak strip called 'Moss Boss' (available on special order from Home Hardware and costs ~ Cdn $30...  comes in a 50' roll, ~ 4" wide and has the same consistency as ultra-thick aluminum foil). 

 

I used a big Home Depot white plastic pail for the tub. 

 

I built a stack of 4 rings of the zinc foil to create a full-depth liner for the pail (rings were stapled to two wood strips at the 12:00 and 6:00 positions to provide some support, with a bare copper wire then stapled on top to electrically link the rings). 

 

I used a thin wood strip (half-round dowel) sitting across the top of the pail as the parts support.  The wood strip has a length of copper wire stapled across the length its top surface.  The parts are hung in the electrolyte bath using lengths of copper wire with hooks bent at each end.  The top hook makes contact with the copper wire on the wood strip.

 

Vinegar and epsom salts for the electrolyte.  The sugar is optional, and is supposed to act as a brightener (most people seems to find that it doesn't really do much).

 

My power supply came from my selection of left-over appliance wall packs. You really need to put both a voltmeter sand an ammeter into the circuit to be able to get a sense of what's going on.  I bought two cheapo multimeters for this purpose @ $10 each.

 

I've just started experimenting with this set-up.  Plating process is fast ( ~ 5 minutes).  The results look promising, but I need to fine-tune a bit.  Too much power creates a really granular coating.  Too little power = no visible coating at all.  It's preferable to put a rheostat controller into the power circuit, but I haven't found one yet with an adequate power rating. As you will see from other write-ups, the plating process is directional (line-of-sight), so getting proper coating coverage for shielded areas of the part can be challenging (I've been working with the Z's tailgate latch as my test piece).  Still, the end effect is pleasing (shiny silver), even if it lacks the rainbow appearance of the factory, cad plating.

 

Bead blast the part(s) for a start.  Wire wheel, if you want.  Acid dip (muriatic should be adequate) to etch the surface a bit.  Then clean in two steps:  degreaser (I use acetone), followed by demineralized water.

 

Warning:  If you try this approach, do not leave your zinc foil in the electrolyte bath between plating sessions.  It dissolves!

[Patcon]

Namerow,

If you bought just the chromates from Caswell you could get the yellow rainbow effect on your parts. The chromate also makes the zinc surface harder and more durable. I like the zinc source as the anodes can be expensive, and the more anode you have the more even your plating becomes.

Charles

[grannyknot]

Well I did pick up the Caswell power supply, some brightner (that doesn't work) and some yellow chromate,

the rest of the kit I hobbled together from reading all the links in this thread.

When they say absolutely clean metal is essential they are not kidding, I started this morning and couldn't even get the zinc to stick, those are the pics of the black bolts.  By 6pm I got the hang of it and produced a few usable pieces, on a couple of the pics you can see how the tinyist amount of grease was left in the pivot and it prevented zinc from adhering

all around it.

De-greaser and muriatic acid are a big help, hard to over do them.

If anyone is interested I can list all the particulars.

A big thanks to Namerow and Patcon.

Chris

 

[Patcon]

Absolutely, particulars would be great! How long did you yellow chromate? Did you use any blue chromate? What was your prep routine?

[grannyknot]

No blue chromate, just yellow

 

8 litres white vinegar

800 grams Epsom salts

1 tsp caswell zinc brightner

pure zinc strip anode (positive)

no added heat- 23*C room temp.

no agitation pump

approx .25A per sq. in., after a while I only paid attention to the amp reading and didn't worry about the voltage

clean pieces with industrial cleaner, then soak in paint thinner, acetone then spray with brake cleaner

then wire wheel down to bare metal, the industrial clnr, acetone,brake clnr

then 10 min in 50/50 muriatic acid/distilled water

rinse with distilled water then into the plating tank for 15 min.

remove with gloved hands and burnish with 3m scouring pad, then back in plating tank for another 15 min

remove, rinse with distilled water then 10 -30 sec in yellow chromate solution

rinse with distilled water and dry off the piece with air gun and heat blow dryer

set aside and don't touch for 4 hrs

[Patcon]

Where were you using the white vinegar? As muriatic or as a prep solution? When 240Nix showed me this he was yellow chromating for about 12-15 secs if I remember right...

[grannyknot]

Vinegar and Epsom salts are the electrolyte, the plating solution.

Muriatic acid as a prep solution. Amount of time in the yellow chromate is something you have to watch carefully, it is sort of dunking for a few seconds then pull out to see if the colour is right yet.

It's easy to go too far,(see pic) and when you do you have to start again at the muriatic acid stage and move to plating again.