Which Congress Tools stone to select to sharpen M4?

Cow51

Cow51

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Hello, I'm looking into new stones for my Sharpmaker and came across Congress Tools 1/2 triangle stones. I heard good things about them, especially the ruby stones. However, in one of the threads I was reading someone mentioned the ruby won't work well on S30V, so I figure it won't work well on M4 either? If so, what stone should I select to sharpen M4?

Thanks
 
I did a recent informal review of using their stones in the following thread, those are the most optimal ones to use for high vanadium steels such as M4. Note in that thread, it mentions I'm not recommending those stones yet as even though I've gotten good results testing them on several knives, I don't know how well they'll hold up with use and over time. You will definitely need to lap them at some point to keep them flat. But if you want to get some, that thread should give some ideas to get started. Short version is you want the MoldMaster SiC stones to cut high vanadium steels, and you likely want a couple of grits: something coarse for bevel setting (I'd suggest the 150 or 240), something medium (320 or 400), and something finer (600 is as high as they go). What I did in several sharpenings was work thru that progression, then refine and finish with super light strokes on the UF ceramic stone in Sharpmaker, followed by strop.

https://bladeforums.com/threads/using-congress-tools-sic-stones-with-sharpmaker.1529283/
 
Though they are Coarse enough to not really be bothered by the Vanadium carbides, Silicon Carbide is not hard enough to shape them.

That said, I've had the best results from the Coarse/Fine DMT and if I want really sharp a microbevels with the Spyderco UF.
 
Using SiC stones to plow steel at the coarse end of spectrum--having used these hands-on with several knives and compared to the Spdyerco diamond rods which is OP's only other option if he's using Sharpmaker--I think the SiC stones do a better job of just plowing the steel, setting clean bevels, etc. And do it a heckuva lot faster than their diamond rods. Agree you still need to finish with something different like UF, which I included in my write-up, and that using diamonds outside of Sharpmaker is even better--the optimal choice. Man I wish Spydie would add a few higher diamond/cbn grits, and maybe one lower grit too.
 
Anyone ever try the Idahone rods for the Sharpmaker? (They're on THIS PAGE, listed as Triangular Honing Rods in C,M,F).
 
Jason B. said:
Though they are Coarse enough to not really be bothered by the Vanadium carbides, Silicon Carbide is not hard enough to shape them.

That said, I've had the best results from the Coarse/Fine DMT and if I want really sharp a microbevels with the Spyderco UF.
Click to expand...
What is the consequence of Silicon Carbides not being able to shape Vanadium carbides? I assume SiC is Silicon Carbide?

maximus83 said:
I did a recent informal review of using their stones in the following thread, those are the most optimal ones to use for high vanadium steels such as M4. Note in that thread, it mentions I'm not recommending those stones yet as even though I've gotten good results testing them on several knives, I don't know how well they'll hold up with use and over time. You will definitely need to lap them at some point to keep them flat. But if you want to get some, that thread should give some ideas to get started. Short version is you want the MoldMaster SiC stones to cut high vanadium steels, and you likely want a couple of grits: something coarse for bevel setting (I'd suggest the 150 or 240), something medium (320 or 400), and something finer (600 is as high as they go). What I did in several sharpenings was work thru that progression, then refine and finish with super light strokes on the UF ceramic stone in Sharpmaker, followed by strop.

https://bladeforums.com/threads/using-congress-tools-sic-stones-with-sharpmaker.1529283/
Click to expand...
I checked out your review, thanks for that. Has your impression of them changed? They sound like they might work for what I need them for. I want to use them for the occasional light reset, while in between being maintained by F/UF stones and a strop. I don't have many knives, they will probably see to 3-4 knives.
 
If you're only going to do the occasional "light reset"--I think you could probably get by with the Spyderco diamond or cbn rods, that might be the better way to go if your plan is basically to buy a knife, keep the factory bevels, just mainly maintenance sharpening. In that case, I don't think you NEED the silicon carbide stones, I'd probably get the CBN rods and then just touch up on UF ceramic if you're staying with Sharpmaker. Of course, the ultimate best way to go--agree with Jason--is to go freehand and use diamond plates like the dmt coarse he suggested.
 
What's the difference between the SiC and CBN?

I would love to try freehand, unfortunately time and money won't allow it now. That's why I like the SM because it quick and easy.
 
For very coarse sharpening, the SiC stones can grind off the steel as effectively as the diamonds or cbn can. But....as Jason said, the SiC material cannot actually "abrade" (sharpen) the carbides that would be in your M4 steel, because the carbides are harder than the SiC material. At higher grits, this would make a much bigger difference and you'd absolutely want diamonds or cbn to sharpen a steel like M4. At lower grits, it doesn't matter as much because you're just coarsely grinding off metal. Jason is saying you'd get the most optimal results with DMT coarse diamond stone, and I agree with that having used that stone to sharpen some of my knives, but the catch is you'd have to switch to freehand, which you said you'd prefer not to.

Given you want to stick with using SM, and the way you plan to use it, I would just get the Spyderco CBN rods and use that to help maintain your knives. I'd only get the Silicon Carbide stones if... (1) You absolutely have no plans to go freehand and will stick with Sharpmaker, and (2) You want to try to do major bevel resetting, edge profiling, etc, on your Sharpmaker.

In reality, you could have the best of both worlds if you don't mind spending a couple $$. Get 1 pair of the MoldMaster Sic stones in either 150 or 240 grit, entirely for coarse profiling and bevel setting work on Sharpmaker, which the Spydie diamond/cbn rods are not good at and very slow. Those coarse SiC stones will profile an edge pretty darn fast, for Sharpmaker. Freehand is still faster, but those SiC stones make it go about as fast and clean as it can possibly go to reprofile an edge on Sharpmaker. 1 pair of those stones plus shipping will be less than $20. Then get a pair of the Spydie CBN rods, which are a higher grit at about 400 mesh, and CAN abrade your high vanadium steels, and you should be covered on all bases. Use the SiC stones only for profiling or major edge repair, use the diamond or cbn rods for your primary sharpening stone for your M4 and other steels. That combo, plus maybe a UF ceramic, will do you pretty good on the SM.
 
F308gt4 said:
You could clamp a diamond plate (or a DMTdiafold) to your sharpmaker rods. Best of both worlds, do a search, there have been lots of pics posted.

Edit: see a pic on post #18 of this thread:

https://www.bladeforums.com/threads/full-sharpmaker-setup-vs-edgepro-cost.1346858/
Click to expand...

Yes that is a good idea. I've seen those before too. In general, if a person wants a guided sharpener like SM and doesn't want to go with the expensive gadgets like Wicked Edge, something like this, or even building your own jig-type setup that you can set different angles and put full size stones into, seems like an interesting idea. I've always wanted to try that, but ya know, so many projects, so little time. :-) IIRC, T tiguy7 has made some jig-type sharpeners that you can adjust to multiple angles, and has threads with pics showing those with full-sized stones on them.
 
The SiC stones iirc are harder than vanadium by a little bit. Is that not enough to sharpen them? I'm just trying to understand Jason's comments in more detail.

I use SiC on the edge pro without issue. I then take it to a SiC strop. I did just recently get some diamond paste and strop on some denim to finish... But only did that on one Knife thus far. I haven't sharpened much recently.

If I were getting stones for my sharp maker I would get the SiC stones (still plan on this eventually). Then finish on strops. Good workin edge. I'm not sure what finer stone options are available for the SM that are more abrasive than the ceramic stones.
 
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cbwx34 said:
Anyone ever try the Idahone rods for the Sharpmaker? (They're on THIS PAGE, listed as Triangular Honing Rods in C,M,F).
Click to expand...
These are high-alumina ceramic. Not gonna work well with vanadium. They will sharpen the steel around vanadium.
 
View attachment 810841 View attachment 810840 My jig looks like this. It was made for the 2 1/2” X 11 1/2” X 1/2” Norton stones, but it works with the 4” X 10” DMT diamond stones and any thing else smaller than that. I also use it with Shaptons, lapping plates with tape backed abrasives, Arkansas Stones, and more recently the new DMT Hard Coat abrasives (shown).
 
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Hey T tiguy7 , thanks for posting, that is sweet! It seems like best of both worlds, a system that lets you maintain a more consistent angle, and flexible enough to accommodate any type of full size abrasive on the market.

For myself, I'm focusing on freehand right now, but seems like this could be really useful for folks who wanted a guided setup but not wanting to get into the expensive proprietary setups like WE. Have you ever made these jigs for sale?
 
I don’t have time to go into production, but the concept is pretty simple for do it yourselfers. I leave one side set at 15 degrees off vertical and the other at 20 degrees. That way I can finish up on a Sharpmaker if I choose. In use I point the edge at the center of the earth and grind away. To do the other side of the blade, I rotate the jig 180 degrees. With an angle cube, I can set the angle to 1/10 of a degree.
 
I picked up a DMT Diafold, It should tide me over until I can get some bench stones. Thanks M maximus83 and everyone else for clearing things up!
 
cbwx34 said:
Anyone ever try the Idahone rods for the Sharpmaker? (They're on THIS PAGE, listed as Triangular Honing Rods in C,M,F).
Click to expand...

Mo2 said:
These are high-alumina ceramic. Not gonna work well with vanadium. They will sharpen the steel around vanadium.
Click to expand...


Thanks... I just wondered if anyone had tried them... wasn't paying attention to the steel being discussed. (Ooops). :confused:
 
cbwx34 said:
Thanks... I just wondered if anyone had tried them... wasn't paying attention to the steel being discussed. (Ooops). :confused:
Click to expand...
I would love to try them — I already own several ceramic honing rods/set-ups, so I’m going to have to wait for a weak moment to pull the trigger! Thanks for the link!
 
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