Best way to remove a black blade coating

Artfully Martial

Artfully Martial

Joined
Jun 8, 2005
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The coating on my Offset has always annoyed me. I hate how black coatings look, but this one scratches unbelievably easily, and I'm getting a lot of spots of rust even through the stupid coating.

So how do I get rid of the stuff? Keep in mind that this has a stud lock, which may have to be taken into account.

Also, what would the finish be like underneath the coating?
 
With all due respect, this style of knife is often black epoxy coated because it's made to appeal to a certain niche market. Unless you want to disguise a deployed knife in the dark it doesn't really serve any useful purpose.

You should be able to remove it with Wet & Dry - I suggest 600 or finer. ScotchBrite will also work but may take a bit longer. Quite often, knives are black coated to disguise a poorly finished blade - I would hope this is not the case with the Offset but you may not be any happier with the results of removing the finish. If you bought this knife as an EDC, I suggest you look at knives that are better designed for this purpose and actually have some CQC cred if that's what you need. If you bought it because you think it's 'tacticool', leave the black finish on.
 
A coating is exactly that - some form of externally applied finish, usually a paint or polymer. Paint, teflon, gun coat, etc all eventually wear off and have little abrasion resistance. The one thing a coating has to do, and won't. TiN/TaN, or DLC are much better. They aren't coatings as much as plating - entirely different, and they have high surface hardness and very low friction.

Removing a surface coating is refinishing, so the blade needs to be removed, studs taken off, and whatever abrasive chosen applied. Often you do find a stamped or even cast blade surface that hasn't been finished at all. Sanding that down to even get the flats consistent becomes a lot of work by hand. My experience with an "MTech" karambit has become a low priority project simply because the time involved isn't worth it. I'd still have a $12 knife when done. Chucking a 600 grit 3M flap sanding drum on a cordless drill would have gotten decent results quicker.

It's a lesson most black blade buyers go through - unless it's electrically deposited or plasma ion bond, black blade coatings are a joke and not worth it. Besides, as a tactical note, if "they" can see the blade, they can just shoot you. It's why all military tool blades are left as is from the makers - only bayonets/pilot survival knives are treated, and that's more for rust prevention. Even the Seals use bare blades.
 
Which Offset do you have? Mine's not coated.

I second the sandpaper suggestion. It's possible to simply pop the stud lock out (at least on my speedbump) for easy sanding. Antonio's correct that it might not be great looking under the coating (it's pointless to do a perfect finish to later coat it). You will actually want to remove a bit of steel. Use coarser sandpaper like 220-grit SiC. Make sure to back it with a block so you get good uniform grinds. I would avoid the area directly under the pivot washers (to preserve action). A cutting lubricant really helps things.

This blade will be a bit strange because of the recessed lettering. Either you'll get contrasting letters, or you'll need a way to sand in there (tricky).

If you start with a coarse-enough grit, and sand efficiently, you'll have a blade this small done in an hour or two.

I sanded off the bead blast finish on my Speed Bump:

3408150696_8a0b168085_o.jpg


Phillip
 
Artfully Martial said:
The coating on my Offset has always annoyed me. I hate how black coatings look, but this one scratches unbelievably easily, and I'm getting a lot of spots of rust even through the stupid coating.

So how do I get rid of the stuff? Keep in mind that this has a stud lock, which may have to be taken into account.

Also, what would the finish be like underneath the coating?
Click to expand...

According to Kershaw, the Offset is coated with Tungsten DLC coating.
http://www.kershawknives.com/productdetails.php?id=370&brand=kershaw

This is likely to be a cast iron B to remove as DLC has a very high hardness. (DLC stands for Diamond Like Carbon). Strippers will not work. The only option is sandpaper. And that's a maybe because the coating may be harder than the sandpaper abrasive.

Good luck.
 
I know what you guys mean...I have always hated black blades, it's just, sometimes the complete package wins me over.

I can't imagine that it would require much work, as just rubbing my fingers against the side of the blade can remove enough coating to make it a little lighter.

But that stupid recessed lettering will be another matter altogether...I was hoping someone had developed a chemical solution for this.

I just figured since it's got like 30 rust spots now, I'd have to remove the finish to remove the rust spots....man....this sounds like a pain.

Why can't knife companies consistently give us the option between coated and uncoated, or for that matter, AO/manual. I'll probably remove the AO while I'm in there.

Thanks for the help guys, I may get around to the project tonight.
 
Artfully Martial said:
I know what you guys mean...I have always hated black blades, it's just, sometimes the complete package wins me over.

I can't imagine that it would require much work, as just rubbing my fingers against the side of the blade can remove enough coating to make it a little lighter.

But that stupid recessed lettering will be another matter altogether...I was hoping someone had developed a chemical solution for this.

I just figured since it's got like 30 rust spots now, I'd have to remove the finish to remove the rust spots....man....this sounds like a pain.

Why can't knife companies consistently give us the option between coated and uncoated, or for that matter, AO/manual. I'll probably remove the AO while I'm in there.

Thanks for the help guys, I may get around to the project tonight.
Click to expand...

ZT and Kershaw give you the coated/uncoated option on a few models. I wish it was more available, though.

Most AO knives can be converted to manual with a carbide drill bit and some skill. The Offset is not one of those. The torsion bars are the only thing keeping the blade in the closed position. Without them, you'll have to tape the knife shut or something.

Does your Offset have a black blade or a gray one? Mine's gray. I though it was just a coarse bead blast, but it might be a coating. I don't think it would look too bad to have matte-gray lettering against a polished blade.
 
I have removed black coatings on several knives now.

First step for me has always been to spray some paint stripper on the coating and wait 15 minutes (just follow the instructions on the can) and then wipe-off with a scouring pad. Now polish the exposed metal to your desired sheen.

This is faster than simply sanding and will leave the edge intact.
 
not really helping, but the black finish on my kershaw ram is amazing, its a tungsten DLC i believe, so its not a "paint" put on the blade

3 months of heavy use and not a scratch
 
The DLC on my zt 301 has exactly one scratch, and that was my fault, I slipped with a sharpening rod. The rest of the blade is perfect, it has been used to cut just about everything, a little soap and water and it cleans up great.

If your coating is DLC, try cleaning your knife. I've thought I had rust on mine, when really it was material left on the coating.

Andy
 
CWL said:
I have removed black coatings on several knives now.

First step for me has always been to spray some paint stripper on the coating and wait 15 minutes (just follow the instructions on the can) and then wipe-off with a scouring pad. Now polish the exposed metal to your desired sheen.

This is faster than simply sanding and will leave the edge intact.
Click to expand...

Offset is coated with DLC. DLC is not paint. Stripper doesn't work.
 
I have several knives coated with DLC and had zero problem with any of them rusting. That includes my WH that I carry when running and gets exposed to a lot of sweat, and my other WH that I have used a fair amount at work and sees tough use.

Maybe you should ask Kershaw if the coating might be defective and see if you can send it back.
 
Well, my Avalanche's finish is MUCH tougher. Never had a scratch, very smooth, doesn't fade, doesn't rust.

The Offset is the gray coating, not the black, so as far as I know, may not be DLC. I think the paint stripper option is my best starting position, due to the stupid recessed lettering and symbols in the blade.

My avalanche's coating has held up well, but my D2 Minigrip's sucked almost as hard as my offset's. Even cutting through cardboard boxes makes fade lines.

The best I've ever had was on my old CRKT M16, the little 3 inch AUS8/aluminum handled model. They claimed it was TiNi. It was very shiny, it really looked like a black steel--kind of gunmetal. It was very natural, as scratch resistant as steel was, and was smooth.

I'm glad to hear the positive stories about coatings as well--I'm sure many of them are good, this might just be a bad application--but my personal aesthetic preferences happen to be against black blades, so combined, I think I'm just going to get rid of it.

Now, how do I pop off the thumbstuds?
 
I just used a few light taps with a punch (on the black plastic) to remove the studs on my Bump. I can't say for sure it's the right way, though.
 
Now, how do I pop off the thumbstuds?[/QUOTE]

They can be pressed in or screwed in, either way you can get them moving by twisting with some vise grips with bits of rubber glued to the jaws or just use rags to protect the studs. If they are pressed in you may need 2 pr. of pliers. I am surprised nobody said sandblasting, is there some kind of problem with it?

I stripped my Camillus Beckers with a belt sander and finished them up with some fine paper.
 

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for the lettering (and the rest) you might try a dremel or similar drill with a soft brass, or even nylon, brush bit.
 
bare metal blades are more tactical. they can be used to reflect light and signal to other members of your team, silently, anyone who's gone through mall ninja training knows this :-D but seriously, i'm going with the majority, i do NOT like black coatings. i started too coarse 320, but barely used it, moved to 600, then 1000, then cotton wheel and emory. mine didn't turn out that great, all my friends think it did, but i can see the effups. all in all, it looks better than the worn out black coating.

jimping was a BITCH and still might have a spot or two of black hiding in there. BE CAREFULL, it is very easy to stab the crap out of yourself while sanding the blade, i did :-(
 
I don't know the knife or the steel but if you get it apart so you are working with just the blade it shouldn't take too long to bring it to even a mirror finish.

If you decide to go ahead with it try some paint remover on a portion of the blade to see if it has any effect. If nothing after 5-10 minutes go at it with 800 grit wet-dry sandpaper sanding in one direction only.

If after ten strokes or so nothing is coming off keep trying with heavier paper until you have results. This way you will not have too many deep scratches to remove. Remember, keep sanding in the same direction until the coating is completely removed.

After the coating is removed you can start moving to finer and finer papers. For instance, if you used 320 grit to remove the coating, sanding from tip to ricasso, and have a smooth surface, move on to 400 grit and sand in the opposite direction (edge to spine) until you can no longer see any of the 320 scratches remaining no matter how you move the blade to catch reflections.

Continue on thru 600, 800 and up in opposite directions each time and you will begin to get the mirror. If a satin look works and the surface is smooth you may be satisfied without sanding further than the original grit used to remove the coating.
 
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