306uf smoothing/rounding corners

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stalag2

Joined
Aug 12, 2012
Messages
79
Hello

I recently bought a spyderco 306uf to start freehanding and so far im quite pleased with the results even with my subpar skill level...However i find the chamfering to be very rough and it somewhat annoys me when dealing with flexible blades and also with wharncliffe type edges.
Also, i would like to use those edges for honing and deburring, how could i smoothen and round them without ruining the stone, my wallet and my wrists ?
 
A common and simple method is to just rub the corners of the rods against each other, if the roughness isn't too extreme. If there are some major bumps in the ceramic, you'd be better off contacting Spyderco for replacements. I think they've been pretty good about taking care of it, when it comes up.

Edit:
I wrote this assuming you were using the UF rods for the Sharpmaker. Now I see you're talking about the UF bench hone. But, same principles apply. Burnishing with another ceramic hone can work.
 
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Use a DMT credit-card dia-sharp coarse to files your 306UF corners & edges. This process either break-in the DMT or ruin it, well at least you will have a 306UF with rounded corners & edges which you can sharpen edges with recurve & serrated.
 
Sounds good but since i dont have a spare diamond stone at the moment ill give a try with my broken grey mini pro file and see how it turns.
Ill get a diafold thingy or whatever my gunsmith has in stock later tho as i really want to round them off.

Also i noticed quite a lot of tooling marks on the whole surfaces, nothing really bumpy but its noticeable once the stone starts to darken, i heard people using DMT benchstones to flatten and lap the whole surfaces, is it worthy to do so considering the price of it ?

Thanx for the advices guys!
 
stalag2 said:
Sounds good but since i dont have a spare diamond stone at the moment ill give a try with my broken grey mini pro file and see how it turns.
Ill get a diafold thingy or whatever my gunsmith has in stock later tho as i really want to round them off.

Also i noticed quite a lot of tooling marks on the whole surfaces, nothing really bumpy but its noticeable once the stone starts to darken, i heard people using DMT benchstones to flatten and lap the whole surfaces, is it worthy to do so considering the price of it ?

Thanx for the advices guys!
Click to expand...

If using a diamond hone to scrub/smooth/flatten ceramics, just be aware that it'll change the effective 'grit' of the ceramic. Almost always goes smoother (less aggressive) than the original factory finish. Spyderco's process (binders and finishing techniques) is what makes a 'medium', 'fine' or 'ultrafine' finish on their hones, since they're all made with the same actual particle size of abrasive. Making them less aggressive may or may not be a good thing, depending on if you want that or not. I've done this with three ceramic hones (using a coarse DMT), and all of them are effectively a much finer grit now, almost glassy-smooth. Great for final polishing stages, but may backfire if done to a medium (grey) Spyderco hone; it won't perform as a 'medium' anymore.
 
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David has excellent points about effective-grit.

306UF is a diamond-polished from baked Fine stone. I ruined a DMT 8XC & (partially ruined) 8C to flatten my 306UF. The 306UF factory surface is not suited for straight razor & japanese hair shears because its low/hi/streak/stripe failed my precision requirement. Mine 306UF surface is now flat & glass smooth 90%, except for 6 small low-corners.

Question yourself if you really want to flatten 24 sq inches of ceramic stone? If you decide to flatten, get 2 of those cheapo HF 4sided diamond stone and hopefully you over-estimate the whole effort, making it more fun than sweat.

I flattened a 8x2F to become a 8x2UF. Flattened 8x2Med to who know what effective grit but still cut faster than a Fine but far from Fine. So I still don't have a super-flat Fine, not sure how I would/could get one or flatten from. These 8x2 stones actually much easier to flatten, I would say 3 or 4 times easier to flatten than the 306UF.
 
How long was the process to flatten your 2 x 8 fine stone compared to the 3 x 8 uf ?
Given med and fine being "right off the oven" how was the finish on them ? ( i noticed my pro files and 204 rods to be slightly concave and not that straight so i wonder how "bad" it looks on such a large surface.)
Could you post a picture of the scratch pattern produced by your lapped med stone ?
Given the factory process for UF surface finish is it safe to say we wont ever see an UF option on the pro file set or any kind of contoured shape ?
 
Est sweat times: 2x8Med 2.5hrs; 2x8F 3.5hrs; 3x8UF 10+hrs

Factory surfaces were rough and untrue flatness (+- 0.5mm) pushed me to wasted/invested all that time:mad:

A little later, I'll edit-post a 50+x mag pics of the lapped 2x8med scratch pattern.

To smoothen out a contour file, just put some 65microns diamond paste on a piece of hard leather or buy DMT flex-sharp coarse => wrap & rub away... yeah excercise those fingers:p

Edit: Scratch patterns on 420J table knife(butter soft hrc) and already you can easily see the lapped ceramic produced highly polish burnished surface. A lapped-medium produces more polish surface than dmt-eef (3micron diamond) because the lapping diamond plate rounded ceramic abrasive surface.

scratchpatterns.jpg
 
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Great! Thanx a lot.

The effect on the medium one is kinda incredible, are you still able to remove enough stock with it to repair moderately dull edges or is it already a finishing stone only ?
How does the stone handle the steel swarf clogging compared to a non lapped medium ?
 
stalag2 said:
Great! Thanx a lot.

The effect on the medium one is kinda incredible, are you still able to remove enough stock with it to repair moderately dull edges or is it already a finishing stone only ?
How does the stone handle the steel swarf clogging compared to a non lapped medium ?
Click to expand...

For the pictures, I use heavy pressure rubbed the heck-out-of the blade (the flat part, not edge). Yes, lapped-medium will remove&burnish metal like a 1k-4k stone depend on amount of pressure. I've tendency to use heavy-pressure, so swarf clogged mine reg & lapped stones up quickly. I use pencil eraser, bkf or AluminumOxide stone to clean them up.
 
Good pics, bluntcut. :thumbup:

That scratch pattern from the 'lapped' Spyderco medium is especially interesting, and seems to confirm what I'd assumed about mine, after I lapped it on a coarse (45 micron) DMT. For all intents and purposes, I couldn't 'feel' any difference in finish, between both my medium and fine Spyderco hones (both sides of a DoubleStuff hone), after I lapped them. Both ended up very glassy-smooth. They do work great for polishing, though. I have an extra DoubleStuff hone that didn't get lapped, so I don't feel like I've given up anything. :)
 
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