Cleaning Copper

I just read through DTR's Reviews/Tutorials of the 2W Sirus-1-C and it's amazing (both the review and the laser) at the end of the review he states that "The only thing I see that I will need to keep and eye on is I have heard that fingerprints on copper is a killer so I assume the host will take a little upkeep. But other than that it is an amazing piece of work."
:drool:

well, in case anyone experiences tarnished copper on any of their hosts I've learned an inexpensive trick my mom uses to clean the copper bottom of pots and pans... Heat+Ketchup

you heat the copper up, get it fairly hot (not with precious diodes or drivers inside of course!) then apply the ketchup. The vinegar in the ketchup combines with the copper oxide to form copper acetate, which dissolves in water so when you rinse the ketchup off, it should be a cleaner, brighter copper.

you can use Rhubarb too but, really, who besides me has a ton of Rhubarb growing in the yard?

You'll probably all just go out and buy some copper cleaner, I know

and for preventative measures, you might get away using a clear coat of resin or paint to prevent such problems in the first place? :wave:

Why not just use vinegar? I guess the ketchup sticks to the copper better then a liquid that would just run off immediately.

Yeah, I think you're absolutely right about that, it's the ketchup's sticky oozing nature that helps it adhere better than pure vinegar I believe.

Yeah... that what I want...
A Laser that smell like Ketchup....

How about using tarnish remover....


Jerry

You can contact us at any time on our Website: J.BAUER Electronics

Tarnish remover doesn't smell as nice, or cost as cheap, or have as many uses

I clean a lot of copper at work... I get the best results using #0000 ultra fine steel wool, and WD-40

On a cylindrical host i recommend polishing the lenght of barrel.

and if keeping it clean is really important to you, i suggest using a degreaser after, then some regular old spray clear coat. I apply it by spraying a paper towel and rubbing it on the copper the same way i polished it.

Michael.

C.L.R. and steel wool works great, just be careful the C.l.r. is hyper conductive. (ive tricked a few water probes in industrial ice machines with a dab of the stuff)

Just use a mixture of equal amounts of muriatic acid dilluted to let's say 10% and hydrogen peroxide from the store (3%). More concentrated mixtures are used to etch copper for PCB printing, but dilluted aren't so aggressive and will remove the oxide layer in half a minute.
Pure alcoholic vinegar works, too, but it's quite slow compared to acid+peroxide.
You could try vinegar+peroxide, that would work well, too.

Ketchup contains fats and you don't want that on your copper...

Actually a tiny bit of water on some Aluminum foil rubbed onto tarnished copper will cause a near instant reaction. It's a simple replacement reaction that'll work to get the dull oxide layer off. Aluminum is much more reactive than copper and as such works well.
Also works on getting Rust off Iron.

That works if the oxide layer is very thin. Aluminium foil method is usually used for removing tarnish from silver, but it always requires more conductive electrolyte. Tap water is a pretty poor conductor so sodium carbonate or bicarbonate is added to it. Even then the process takes minutes, sometimes even hours to work, given the thickness of the tarnished layer. Copper behaves similarly.

Rubbing only makes things worse as it introduces new grooves which are hotspots for future oxidation.

I've got no experience with laser heatsinks, but based on my knowledge of material properties, I'd try to make a fresh, bright red copper surface using vinegar+peroxide, dry it by wiping and then I'd smear thermal grease at its surface that contacts the host. Grease would ensure no further oxidation could occur, and the metal particles inside would make a tight, conductive fit for the heat to dissipate.

I prefer aluminum anyways... doesn't hold heat as long, not as dense as copper and hardly a need to clean.

When you use the acid approach... I find that the copper tends to tarnish much faster afterwards. And the acid does something else. I notice the copper color is less pronounced, almost like the acid eats some the orange color.

Michael.

Use a metal polisher. I have some POL and it works very good. It leaves also a protective film over the metal that can proctect the metal for long time.

Some examples after using POL polisher.

chipdouglas said:

When you use the acid approach... I find that the copper tends to tarnish much faster afterwards. And the acid does something else. I notice the copper color is less pronounced, almost like the acid eats some the orange color.

Michael.

Click to expand...

That's true if you're using aggressive approach with concentrated acid (real PCB bath). Small cavities form and their surface is squeaky clean. The acid doesn't do anything special, it simply removes everything in the path, leaving pure copper surface.
Copper tarnishes and that's a fact. It's being attacked by the air and the moisture. First it gets orange, and then, at the end, you've got a basic copper carbonate which is green in colour.

Copper is not orange at all. True, clean copper has a bright red tint. The muriatic acid actually pronounces its color vividly. The orange color is due to thin layer of oxides and grease.