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View Full Version : How to Restore Black Finish on Drill Chucks



Paul Alciatore
07-13-2016, 04:41 AM
I am still working on all the rust on my tools from when they were in storage. Currently working my way through my drawer full of drill chucks. I have been starting with letting them soak in a coat of oil overnight and then using a brass brush. That has taken care of the light rust. If that doesn't work I switch to a steel brush. And if that doesn't do it, I am using carefully applied naval jelly. After the rust is removed, I polish them up with Scotch Brite pads of which I have three different grades.

I obviously can not remove any pits this way, but it seems to do a pretty good job. However, the naval jelly also seems to be taking off the black finish on some of the chucks. I don't know what this finish is, but it has been applied between the ribs on the outer collars for a decorative appearance. I wouldn't mind if it was all removed, but it is only removed where there was rust.

So I am wondering what the best way to restore this finish may be. Could it be a paint? It seems to extend into the teeth on the chuck which are also black. So it would seem that paint would chip off. Black oxide? How did they apply it in stripes? Something else?

This is not a name brand chuck, just a Chinese import. I have at least two of them.

MichaelP
07-13-2016, 04:55 AM
This is black oxide. Unfortunately, things similar to Evapo-Rust remove it quite effectively.

If you want to go through the trouble of restoring a similar kind of finish, read on parkerizing. Here is a good thread: http://bbs.homeshopmachinist.net/threads/39446-Let-s-Parkerize-Something!

Toolguy
07-13-2016, 10:19 AM
It's probably black oxide. You don't apply it in strips, you oxide the whole thing, then sand the high parts. Preferably do the sanding with the chuck spinning in a lathe or drill press. Then you are left with alternating black and silver stripes.

Euph0ny
07-13-2016, 10:54 AM
Sounds like the black "finish" is black iron oxide (rust being red iron oxide). Commonly also known as gun bluing or blacking. Any of the proprietary "cold" gun blue/black touch-up compounds will probably serve to restore your black look, though you might have to try a few to get the colour/tone you want.

Using them is pretty simple - degrease the area, swab on the product and let it work for a while, rinse off in water, disperse the water with WD40, oil the part. I find warming the part first and rinsing in hot/boiling water are helpful.

https://www.youtube.com/watch?v=dgYG903kYGo

EddyCurr
07-13-2016, 11:52 AM
Photos and discussion about cold blue in the following thread.
The 'after' photo quality is disappointing. Still, it may offer
some guidence as to whether this is the route for you.


Restoring The Finish on Rusted Spring Steel (http://bbs.homeshopmachinist.net/threads/67606-Restoring-The-Finish-on-Rusted-Spring-Steel) 2015.07.29

.

BCRider
07-13-2016, 12:39 PM
From my own home gunsmithing I've tried a few different cold blue products. The one I've found works by far the best is G96 brand "Gun Blue Creme". It's a gelled product that you'll find at outdoor stores that cater to hunting and which sell gun care products. Shouldn't be a problem what with you living in Texas.... :D

It helps if the item is well warm to the touch before applying the bluing. And needless to say it has to be fully degreased. And wear disposable gloves to avoid skin oils on the surface. For something the size of a drill chuck apply it with an acid brush.

If the finish is a little spotty you can "card" it with some degreased fine steel wool. It'll cut down and even the bluing. Degrease again just to be sure then apply a second treatment. Card off this second layer with a stiff nylon bristle brush. A "hard" toothbrush is just about perfect for this. I also find that doing this last nylon bristle carding under hot running water aids in setting the blue a little better.

At that point dry it and add a thin coat of oil and it should be looking pretty nice.

Paul Alciatore
07-13-2016, 03:59 PM
Boy, I looked at that thread. There is NO WAY that I am going to go to that much trouble for some import drill chucks. NO WAY! IIRC, I bought at least two of them from Grizzly when they were on sale. Probably paid around $15 for them. And they will work just fine as they are.

But thanks for the reference to that thread.




This is black oxide. Unfortunately, things similar to Evapo-Rust remove it quite effectively.

If you want to go through the trouble of restoring a similar kind of finish, read on parkerizing. Here is a good thread: http://bbs.homeshopmachinist.net/threads/39446-Let-s-Parkerize-Something!

metalmagpie
07-13-2016, 04:07 PM
I would suggest chucking up a 1/4" rod about 10" long and using it to hang the chuck in an electrolytic derusting bath. You can clip your black lead right to the top of the rod. With the rod securely chucked, it should conduct electricity fine. A little current and time later and all the rest of the black will be gone and they will look better.

You could also try painting the black cracks with black fingernail polish, drying with a heat gun, then spinning it up and sanding with superfine sandpaper folded over a file (to keep it from going down in the cracks at all). Who knows? It might work, and it won't cost you much, and you will certainly learn something. Please post the results so we can all learn something.

metalmagpie