Filling Pitted Round Knife with Epoxy for refurbishing

[dikman]

I would have expected some change after all that time. I did it using lead sheet as the anode and it worked pretty quickly.

As for the broken tip, I would grind the flat/straight part to bring it to a point again. You could use an angle grinder or a bench grinder if you don't have a belt sander. The trick is to take it slowly and keep cooling the metal.

[AlamoJoe2002]

Dikman: I have a belt sander...I'm looking for design ideas to change the symmetrical profile to asymmetrical...almost a two in one round knife.

7 hours ago, dikman said:

As for the broken tip, I would grind the flat/straight part to bring it to a point again. You could use an angle grinder or a bench grinder if you don't have a belt sander. The trick is to take it slowly and keep cooling the metal.

I was thinking I need a sharpening board to mount the blade on for sanding. I'm thinking about using a handheld sander in straight line sanding (lateral as opposed to round) movement. If I can use the 10 inch portable sander I can really work on a gradual reduction of material to the cutting edge. I have a feeling I will be starting out with 80 grit paper or more aggressive sandpaper and hours of relaxing mind numbing meditation while I hand sand this blade down.

My goal is a sharp shinny blade and something like world peace...

Joe

 

[Tugadude]

Bikes with surface rust get a bath in oxalic acid solution.  Seems to do the trick.  Heard hydrochloric acid works too.

Caution is urged.  Protection and safe disposal required.

[dikman]

Ok, if you want to make big changes to the shape then yes, you're in for a lot of slow sanding/grinding, given that it's already hardened. There are lots of photos of different shapes that came up when I did a google search some time ago.

As for your last statement, sharp and shiny is achievable, world peace not so likely.

[bruce johnson]

On 5/28/2021 at 4:06 PM, AlamoJoe2002 said:

I have an CS Osborne, Newark NJ,  Round Knife due in which will be my 1st round knife. The metal blade is pitted. Hopefully I can work on the blade without removing the handle. I would like to remove the rust using electrolysis by suspending the blade into solution and adding current to remove the rust. Then instead of removing material to the lowest pitted level, I propose to fill in the pitting with a metal epoxy, then begin profiling the blade by hand using various grits of sandpaper.

Do you have a few words of guidance for the electrolysis rust removal? 

How about products for filling in the pitted metal?

How do I protect the manufacturing stamp when I begin to sand down and profile the blade? 

I also like the idea of reworking the #70 Blade into a more custom knife similar to the Terry Knipschield non-symmetrical Round Knife.

Then again, I want my first knife sharp, shinny, and a pleasure to use as it will be mine!

Joe

I don't want to rain on the parade, but that knife probably won't be what you want. I get several a year like that. Good chance with all that pitting you may arrest the ongoing corrosion but the steel may be pretty crumbly. That broken tip is pretty big and no small feat to grind a new shape without taking out any temper that may be left in it. By the time you get to thinning the edge there may not be much left. CS Osborne Newark marked knives are not particularly rare and I just don't see any work on this one to be time well spent. 

[AlamoJoe2002]

Thanks Bruce. You have got me thinking...may be I need a new specimen to spend my time on. I truly am looking forward to learn how to properly sharpen and use a round knife.

The blade is still in the electrolysis bath. The pitting is still bubbling the rust away. It has been 24 hours and I don't see much of an improvement to the blade material. I will keep up the process and see how long it takes in solution for the reaction to stop.

So in the mean time I am now on the look out for a round knife to clean up, sharpen , and make it mine. Right now I paid $26 US for the knife. I will begin the hunt for a new specimen. I feel honored to have Bruce weigh in on this project. If anyone has a vintage round knife they would like to pass along at a reasonable price please send a PM. I say vintage because the train of thought is the newer manufactured knives on the market are produced with lesser quality steel.

JOE

Joe

[dikman]

For only $26 I think it's worth persevering with it! I'm sure you will end up with a usable blade. As for your last statement I understand where you're coming from but it's not necessarily the case, it will depend on the manufacturer. The older blades would have been plain carbon steel (hence the rust) but there are many steels available these days that are better, with greater edge-holding and toughness. Personally, I am fond of carbon steel, even though it requires more care, and that knife of yours has a great patina which reflects its age.

[Frodo]

list of gun shows in your area   the pitting shown is easily sanded off,  

 if you want to use that knife for years and years, have the pits knocked off and the edged trued by a pro. 

 

• JUNE 5-6, 2021 – PA, GETTYSBURG | Gettysburg Gun Show. ...
• JUNE 11-12-13, 2021 – PA, OAKS | Oaks 3-Day Gun Show !!! ...
• JUNE 12-13, 2021 – PA, LEESPORT | Leesport Gun Show. ...
• JUNE 26-27, 2021 – PA, YORK | York Gun Show.

[chrisash]

There is so much talk about poor blade quality and the need to keep polishing the blade, I do wonder what difference it makes to the average (if there is such a thing) leather worker who cuts out one item maybe a day rather than the professionals who may spend all day cutting out, after all, many but not all would probably just cut out one Wallet, or Bag, maybe a couple of belts in one go so how blunt would a knife get in that process

[chuck123wapati]

6 hours ago, dikman said:

For only $26 I think it's worth persevering with it! I'm sure you will end up with a usable blade. As for your last statement I understand where you're coming from but it's not necessarily the case, it will depend on the manufacturer. The older blades would have been plain carbon steel (hence the rust) but there are many steels available these days that are better, with greater edge-holding and toughness. Personally, I am fond of carbon steel, even though it requires more care, and that knife of yours has a great patina which reflects its age.

Ditto what Dikman said also what Frodo says clean it up and have a new edge put on and enjoy it, your way over thinking this whole process. After the new edge is on you can then more easily learn to keep it sharp.