Tips for proper Magna-Guide use?

[mcmc]

Hi gang,

Searched, but didn't quite see what I was looking for.

I have a DMT Magna-Guide, and DiaFolds from XCoarse all the way down to XXF (though, my XCoarse is a single-sided one, and thus when used on the Magna-Guide, it has a slightly different angle from the double-sided DiaFolds - wish they had mentioned that in the ad copy! so now I need to buy a double-sided XC, I guess an XC-C one).

I reprofiled and sharpened a knife on it, and it worked great, but had these questions:

1. The slot the metal bar goes into, it matters which side of the slot you push the bar against, right? Since that will slightly alter the angle at which the diamond surface hits the edge? So, do you guys just pick a side to push against, and stay consistently there?

2. The angle changes depending on where the knife is clamped - toward tip, toward ricasso/bolster, deep on spine, shallow on spine... So, how do you go back to the same angle when you go back and re-sharpen a knife you've already given a once-over on the Magna-Guide before?

3. Any other tips on how to best and consistently use the MG?

Thanks!!

ps. I can freehand ok, but I do like the consistent edge angle that the MG can give, hence the thread.

 

[Obsessed with Edges]

Hi gang,

Searched, but didn't quite see what I was looking for.

I have a DMT Magna-Guide, and DiaFolds from XCoarse all the way down to XXF (though, my XCoarse is a single-sided one, and thus when used on the Magna-Guide, it has a slightly different angle from the double-sided DiaFolds - wish they had mentioned that in the ad copy! so now I need to buy a double-sided XC, I guess an XC-C one).

I reprofiled and sharpened a knife on it, and it worked great, but had these questions:

1. The slot the metal bar goes into, it matters which side of the slot you push the bar against, right? Since that will slightly alter the angle at which the diamond surface hits the edge? So, do you guys just pick a side to push against, and stay consistently there?

It doesn't matter. The ever-so-slight variation that might be introduced in that will be so insignificant, you'll never be able to see the difference. There's more variation introduced by the size of the holes in the guide, which allow the rod to move up/down a bit. Even that can be minimized by taking it slow & controlled, so the rod doesn't bounce around in the opening.

2. The angle changes depending on where the knife is clamped - toward tip, toward ricasso/bolster, deep on spine, shallow on spine... So, how do you go back to the same angle when you go back and re-sharpen a knife you've already given a once-over on the Magna-Guide before?

This is the one major thing that's really wrong with any guided setup. I've always wished they marketed these as 'edge reprofiling tools', as opposed to just 'sharpeners'. A lot of people don't know what they're really getting into, when buying one of these. If you've watched any of DMT's videos for these systems, the 'sharpening' they demonstrate in the video amounts to applying a simple microbevel. They place the blade on the hone at an angle that's obviously higher than the factory bevel, and make about 6 strokes per side. And 'voila!', that's it. That will work fine, on a blade that's already got a good primary bevel. But replacing the whole bevel is never demonstrated in the video.

For what it's worth, I've never used my guided sharpeners (Lansky, Gatco and DMT Magna-Guide) to maintain my edges. I only reprofile edges with them (which works great). All of my touch-ups, afterwards, are done freehand. The good thing is, freehand is considerably easier when you have a good, symmetrical bevel to start with. So, I still see great value in the guided setups for putting a good bevel on, in the first place.

3. Any other tips on how to best and consistently use the MG?

Most important thing is to make absolutely sure the blade is clamped correctly, with flush contact between the blade and the inside faces of the clamp. Make sure the blade doesn't move/slip at all. Taping the blade with masking or painter's tape helps, and my favorite means is to use a piece of wet/dry sandpaper (medium/fine grit), with the grit side toward the clamp and the paper backing to the blade, wrapped over the spine, to keep the blade from slipping. Works very well, even when wet, which is sometimes a problem with tape, which can come loose or slip if wet.

Otherwise, keep your pressure very light with the hones, and take it slow, controlled & easy. This will help minimize any movement of the blade in the clamp, and is generally good sharpening practice anyway. Results will always be better. From my own personal experience, the Magna-Guide rod can also come loose from the hone, if you lean on it too hard. Even if it doesn't come off, the rod can still bend or deflect a bit, if pressure is too heavy. This will introduce some more angle variation as well. So keep reminding yourself to keep it light & easy.

 

[mcmc]

Thanks David! That's exactly the kind of experienced input and advice I was hoping for =)

Makes sense regarding the side-to-side movement not being as big a deal as the vertical.

And what you said about the MG being more of a reprofiling aid also totally makes sense, that's kind of where my hunch was leaning. Just too impossible to get back to the same positioning to maintain the same edge.

I like the semi-convex bezel that ends up happening when I freehand anyway.

One thing though - do you have any tips for where/how to place the clamp, or in the sharpening motion, to keep "fat tip" from happening? I've seen knives profiled on the MG that have a pretty even bezel width all the way through, but couldn't figure out how

 

[Obsessed with Edges]

Thanks David! That's exactly the kind of experienced input and advice I was hoping for =)

Makes sense regarding the side-to-side movement not being as big a deal as the vertical.

And what you said about the MG being more of a reprofiling aid also totally makes sense, that's kind of where my hunch was leaning. Just too impossible to get back to the same positioning to maintain the same edge.

I like the semi-convex bezel that ends up happening when I freehand anyway.

Me too. The guided setup does a great job with the edge itself, after which I like to use wet/dry sandpaper on my strop block to convex the shoulders of the bevel. Makes for truly excellent slicers.

One thing though - do you have any tips for where/how to place the clamp, or in the sharpening motion, to keep "fat tip" from happening? I've seen knives profiled on the MG that have a pretty even bezel width all the way through, but couldn't figure out how

By the 'fat tip', I assume you're referring to the wider bevel near the tip? If so, there are a few variables affecting that, most of which relate to the blade itself. The positioning of the clamp makes a difference on some blades (longer ones in particular). I've been in the habit of measuring the distance between the upper portion of the guide, where the rod passes through it, and several chosen areas on the edge (like heel, mid-blade and tip). Try to keep the clamp relatively the same distance from all points. That helps with some, but not all blades. Some blades won't allow a lot of options for the clamp position, depending on the grind & overall profile of the blade.

Another variable is the thickness of the steel near the tip. A blade with an upswept tip will almost always have thicker steel at the tip (edge sweeps upwards to meet the 'spine', which is always thicker than other portions of the blade, further from the spine). Thick steel at the tip will mean the bevel will have to be wider, given the same edge angle.

A third variable is in how aggressively the 'belly' of the blade turns upward to the tip. Some will have a fairly even radius in that sweep, which makes positioning the clamp more equidistant from the sample portions of the edge somewhat easier. In some cases, you'll even see blades with a certain sweep to them, which allows the clamp to be positioned all the way back at the tang, and still produce a very even bevel width along the full edge length. I have one like that, which also features a high hollow grind (steel is relatively thin, until just below the spine); best of both worlds for an even bevel. More often than not, however, you won't be quite that lucky.

And yet another variable is the angle setting you've chosen. Lower (acute) angle settings will produce a more extreme-looking variation in bevel width along the edge, to the tip. Choosing a slightly less acute angle might help some, with thick-tipped blades. But again, that's not guaranteed to work on all blades.

One reason I like to convex the shoulders of my bevels is, it's easier to 'blend in' a bevel this way, if there's wide variation in bevel width along the edge. On very acute edges in particular, the wide bevel at the tip really works to advantage for this, producing a tip with excellent piercing/penetrating characteristics. All of my best slicing knives have been done in this fashion.

 

[mcmc]

Cool, I've never tried the sandpaper stropping - right now I have a two-sided strop, one with 6-micron DMT paste, and the other with 1-micron.

Yup, that's exactly what I meant by fat tip. Thanks for all the description on where to place the clamp, and what affects the edge.

I wish I could remember where I saw a pic of someone who used the MG but seemed to have a very even bevel width all across the edge. So, there's no special way to move or position the dia-fold itself, during sharpening/reprofiling, to get there, right?



On a related note, when you freehand, do you use a dia-fold? Sometimes I have trouble with the tip, since it catches on the circle cutouts. Any tips on that? (no pun intended)

 

[Obsessed with Edges]

Cool, I've never tried the sandpaper stropping - right now I have a two-sided strop, one with 6-micron DMT paste, and the other with 1-micron.

Yup, that's exactly what I meant by fat tip. Thanks for all the description on where to place the clamp, and what affects the edge.

I wish I could remember where I saw a pic of someone who used the MG but seemed to have a very even bevel width all across the edge. So, there's no special way to move or position the dia-fold itself, during sharpening/reprofiling, to get there, right?

I think that's something you'll need to develop a 'feel' for. I don't know if there's really a 'best' motion or positioning. I experiment with these things on a continual basis, and it really comes down to individual feel for it, and what is most comfortable for your hands (this is VERY important; if your hands aren't comfortable, or getting sore/tired too quickly, results will always suffer). What I mentioned earlier, about taking it light, slow & easy, it has a double payoff. Better results at the edge, and it'll really help save your hands & minimize fatigue. Don't know how 'young' your hands are, but mine are beginning to feel some of the effects of middle-age. I'm really paying attention to anything I can do, to keep them from being too sore at the end of the day (and for a couple days after).

On a related note, when you freehand, do you use a dia-fold? Sometimes I have trouble with the tip, since it catches on the circle cutouts. Any tips on that? (no pun intended)

I sometimes freehand with my Dia-Folds. With the tips of the blades, I always kind of 'pull' the edge diagonally across the hone (I do this using the guide also), which keeps the tip pointed in a direction away from the direction of motion ('tip-trailing', in effect). As mentioned before, keeping pressure very, very light is critically important here, so you don't drive the tip into a recess. Just let it gently 'skate' across the surface, and take it very slow and controlled. Placing the pad of a fingertip near the blade tip, very lightly, can help you 'feel' how that portion of the blade is contacting the hone, and lends greater control.

 

[17pes]

Sorry, just saw this post and wanted to jump in and ask a question. I just got a hold of a dmt aligner, and I think I understand about the back bevel and profiling (always just put a working edge on quickly, not even necessarily razor sharp) but since I got on blade forums I've been learning about quite a few new technique and sharpening styles. Any suggestions on something to improve on the edge I can pick up with the aligner stones?

Thanks. Sorry for crashing the thread. Kinda new here.

 

[mcmc]

Thanks David. My hands are ok, so far - had about of RSI/tendonitis a while back, but strictly held to dr's orders and didn't do anything with my hands for one month - it was hard, but then I got stronger and I'm pretty much 100% now. But yeah, hear you about making things easier if you can!

I think I was overly ambitious in trying to follow the angle through to the tip, and forgot how I used to do it - which is similar to how you describe, pulling backward toward the tip. "Duh" =) Thanks for your tips there though.

Would be cool if you had a Youtube vid of you sharpening or honing! =) What knives do you EDC, and therefore sharpen often?

 

[mcmc]

Sorry, just saw this post and wanted to jump in and ask a question. I just got a hold of a dmt aligner, and I think I understand about the back bevel and profiling (always just put a working edge on quickly, not even necessarily razor sharp) but since I got on blade forums I've been learning about quite a few new technique and sharpening styles. Any suggestions on something to improve on the edge I can pick up with the aligner stones?

Thanks. Sorry for crashing the thread. Kinda new here.

Welcome! I think the tips David posted in this thread would apply to you as well.

Have you tried freehand sharpening, on some cheaper knives?

 

[Obsessed with Edges]

Thanks David. My hands are ok, so far - had about of RSI/tendonitis a while back, but strictly held to dr's orders and didn't do anything with my hands for one month - it was hard, but then I got stronger and I'm pretty much 100% now. But yeah, hear you about making things easier if you can!

I think I was overly ambitious in trying to follow the angle through to the tip, and forgot how I used to do it - which is similar to how you describe, pulling backward toward the tip. "Duh" =) Thanks for your tips there though.

Would be cool if you had a Youtube vid of you sharpening or honing! =) What knives do you EDC, and therefore sharpen often?

I've never been too enthusiastic about doing vids. My internet connection is horrid slow, by today's standards. As far as the 'visuals' go, regarding sharpening technique, there are already plenty of good examples out there. Murray Carter's are a reliable reference, and our own 'Knifenut1013' has started doing some of his own; his results have always been impressive, and his posts very informative.

As for my knives, I carry and/or sharpen a variety. I spent a long time collecting them before learning how to sharpen any, so I have a nice stockpile of them to choose from. Don't have the $$ to support the collecting habit as much, so my new focus is on learning how to sharpen each of them. I've done 420HC (Case & Buck), 440A (Camillus), 440C (Boker, older Buck), AUS-8, 8Cr13MoV (A.G. Russell), Sandvik 12C27M (Opinel), VG-10 (Spyderco), 1095 (Schrade, Camillus), D2 (Queen), S30V (Kershaw/ZT and Lone Wolf), and countless 'mystery steel' kitchen knives. Learned a ton about 'abrasion resistance' from the S30V and D2, about burrs & wire edges from 420HC, VG-10, ATS-34. And the differences between steels with very hard carbides (S30V, D2) and those without them (1095 and simpler stainless like 440A, and Victorinox's stainless), and how each responds differently to different abrasives. Still have many more to learn new stuff from, too.

 

[17pes]

Thanks.

I haven't tried free hand yet, other than putting a working edge on. Nothing like the hair splitting stuff that people post up around here. Definitely willing to take a crack at it, but all I have for now is a dmt set and an old coarse pocket stone. Had my interest piqued by the paper wheels method, too.