Caswell Black Oxide coating -EASY!! (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

MrMoMo

That's not rust, it's Canadian patina...
Joined
Nov 11, 2005
Threads
172
Messages
2,456
Location
~Kingston, ON, pero soñando de Panamá
So, I'm currently rebuilding an FJ40 (or two) and just couldn't bring myself to put the old rusty nuts and bolts back to hold it together, but also hated the fact that without doing this I would have a huge bin of useless nuts and bolts. (And would need to spend a small fortune on new bolts!)

I knew there had to be a better way than individually sand blasting or wire wheeling each piece of hardware, and after that, having to set up some sort of electroplating system.

I took a few long hard looks at the Caswell Copy Cad system, and though it looked great, I couldn't begin to imagine the time or math it would take to figure out how much current would be required for the surface area of 37 nuts and bolts in a batch, let alone having to wire them all up individually.

I found the Eastwood Hardware tumbler and thought I would give it a try for "batch cleaning" where I could start it up and walk away. That system worked like a CHARM!

So, now that I knew the cleaning worked, I had to find a good coating system. Paint wouldn't do, it adds to the diameter and chips off. Zinc or "copy cad" coating would work, but it's not exactly a simple setup, or large batch process. I could send them out to be done, but then the cost factor eliminated the purpose.

Yesterday I tried Caswell Black Oxide - it's a totally simple straightforward and very inexpensive process (I paid $39 CAD, and have used about 1/10th of the solution so far to do everything you see in the video). If you have small parts,
like hardware, that you want coated black - check this out!

 
Black oxide has a fraction of the corrosion resistance of zinc. Yellow zinc plated parts will look much better for a much longer time.

There’s no need to calculate the surface area with each batch of zinc plating. There are a couple different ways of approximating the necessary current. One of which is to calculate it for one part in your first batch and witness the amount of hydrogen gas being produced on the part. You could then adjust the current output of your power supply on the following batches to approximate the same reaction.
 
I found the Eastwood Hardware tumbler and thought I would give it a try for "batch cleaning" where I could start it up and walk away. That system worked like a CHARM!

A cheap method I use is soak the rusted parts in citric acid in a glass beaker. I buy it as a powder form (food grade), weigh a few grams, add water to desired concentration, leave overnight, rinse & dry when done. It works great with rusted iron and tarnished copper/brass and if you heat up the water it works faster. The acid seems to work on the oxide only as I presume is too weak to attack the metal itself.
 
I've used "rust dissolver" in the Eastwood cleaner at the same time as the green media, it does a good job of speeding up the process as well. I do batches through with Superclean to degrease, then rust dissolver to get all the rust off, and then polish. They come out like new!

 

Users who are viewing this thread

Back
Top Bottom