Convex grind change possible?

[Roefisher]

Hi folks,

I was just wondering what options I have now that I want to change my convex grinded blades. The knives I am thinking about are an F1, a Northstar and an Aurora.

What I was considering doing was cutting a 1mm bevel on them like my flat and hollow grinded blades or maybe even going a bit furthur back and making a little scandi grind. I have an Edgepro sharpener so I can do full reprofiles fairly handy.

How would those ideas work or does anyone have a better option? I am open to any ideas other than, "leave it alone Mark, you headbin!"

Mark

 

[British Red]

Roefisher,

I'd try it. Several people on here have tried it - some with great results. The more I try it, the more I hate the convex grind. I can't get on with my F1 and asked Mike Stewart to consider a scandy or flat ground Aurora (don't advise anyone else to try this ). Others love their convex but I just can't get on with it. Some went to the extent of lending me a couple of BRKTs (including the North River). Nope. Just plain don't like it.

If you get any good at it, you do my F1 - if you can take it back to a scandy or flat. I believe Stuart Mitchell has done this for someone and Leon1

I'd love to hear how you get on with doing this

Red

 

[Roefisher]

That's for the support, Red - phew!

Now, I was thinking on starting off with the smallest change first. By that I mean a 1mm bevel and leaving the rest of the blade convex shaped. Then if that needed furthur adjustment either in the bevel length or blade profile, go on from there. I suspect that I'll end up cutting off the convex belly and have a flat blade but that's still to come.

All being well, I am going out to the river all day tomorrow so I'll hopefully get a start made on the Northstar sometime around thursday or friday. We'll see how that goes but I am really looking forward to trying this!

Mark

 

[British Red]

Sounds great mate - if you have a wee search around here, you'll find several more in the "don't like convex camp". I suspect its a bit like the down vs synthetic argument - its a personal thing. For me though - flat grind all the way!

Really love it if you would post how you get on as I am seriously debating throwing my F1 away since I don'y like it and its really bad wyrd to pass on a bad blade

Red

 

[Ahjno]

Sounds great mate - if you have a wee search around here, you'll find several more in the "don't like convex camp". I suspect its a bit like the down vs synthetic argument - its a personal thing. For me though - flat grind all the way!

Really love it if you would post how you get on as I am seriously debating throwing my F1 away since I don'y like it and its really bad wyrd to pass on a bad blade

Red

In that case I'm offering it a good home for free and no charge - just for you Red, because it's Christmas

 

[British Red]

You aren't the first mate - but, as I said, I have a problem with passing on bad blades - I dunno - I'll keep looking at it till I can think of what to do with it

Red

 

[Xunil]

I love convex ground knives for outdoors use, but I always slim my F1 blades down, while maintaining its convex shape.

The F1 is a fine piece of kit but far too thick through its cross-section, which can make it less effective in use and more difficult to look after and maintain over the long term.

If you're going to regrind it/them with a Scandi style grind it seems more practical, at least to me, just to trade them for Scandi knives.

I have an F1 that I've used for several years and it cuts like a dream. It has a tapered tang, the blade is far thinner (although still convex) and it's drop dead easy to keep sharp.

An unmodified F1 may be stronger, but it does everthing else less well than my reground blade. I've just stripped its scales off for refitting, but I can post a pic of my reground F1 compared to a standard F1 if you'd like to see the difference in cross-section.

 

[British Red]

Xunil,

I'd love to see the pictures please (although I'd probably get it ground flat instead). When you say you stripped the scales off, was it a Micarta one (I guess it wasn't the thermorun style)?

I here what you say about thinner but I've tried thinner convex and they still don't work as well as a flat grind in my hands. I guess trading is possible, but I feel wrong about trading something that I think is an inferior knife. BTW, how does anyone bore with that point? Its so round that it carves bowls not holes

Red

 

[Xunil]

I'll try to get some pix sorted tomorrow in natural daylight.

It was a Micarta model - I took to Micarta off, tapered the tang (which sooooooooo improves the feel of the F1) and fitted Curly Birch, which looked great and held up over several years of hard use.

I ripped the Curly Birch off last week with the idea of fitting some new scales, but I've not had the time as yet. What I have done is drop the point slightly and slim the blade cross-section right down.

There's nothing I can do with a Scandi ground blade that I can't do with my modded F1 and vice versa.

Out of the box though, you're dead right. The F1 point (as well as the rest of the blade) is meant to be as close to unbreakable as a knife can be, which is manages very well by having so much metal there. It's still one of the very best production outdoors knives available purely because it is to damned strong, but many users find it very difficult to maintain and use due to its thick cross section and exaggerated convex.

 

[British Red]

Look forward to seeing the mods. We'll agree to disagree on the equality of convex vs flat I hope.

I personally am beginning to think theres a reason why almost every wood working tool and chefs knife in the world is flat ground. There is of course one type of tool that almost always comes convex - and thats an axe. If I planned to baton a knife (impact cutting) a lot I can see an advantage in all the extra metal protecting the cutting edge. Push cutting though most closley resembles the action of a chisel (chisel or sabre grind) and being able to lay the grind completely flat to the cut makes sense where a convex must mean one needs to use a more obtuse angle, slicing demands the flat grind and narrow spine of a chefs knife to asisst in minimal resistance. Now in bushcraft we tend to want to do all these things, so any knife is a compromise - I just like the compromise of a convex least I guess. If I batoned more and really "hard used" my knife for levering and prying, I'd probably swear by the F1 (rather than at it ). However I always carry an axe for heavy work and use my knife mainly for push cutting wood and slicing meat. I completely understand that others use what they like - its not just a question of ability to maintain the edge though - the blade geometry lends itself to different jobs (unless the convexing is so miniscule as to be effectively flat ground). Anyhow, your mileage probably varies - everyone elses sure does

Red

 

[Xunil]

You've started something now...



I've no problem with agreeing to disagree, however:

I NEVER baton a knife, regardless of grind. I've never had to and don't ever anticipate having to, despite years as a survival instructor (and knifemaker).

A carpenter or chef has next to nothing in common with an outdoorsman, although I agree that an outdoors knife has food preparation and some wood cutting high on its list of primary tasks. Most of my knife use is as a slicing tool.

Cutting tools vary the world over and even within the same country there can be startling variations.

I've spent a lot of time in Norway and Sweden, including showing and selling my knives, and what most people over here aren't aware of is that the vast majority of their Scandi ground knives go back to a maker at some stage to have the blade reground when the secondary bevel gets too steep to take a good edge.

Most Scandi ground knives over there are sharpened with a secondary bevel, which eventually ends up with an angle so unworkable the blade has to be completely reground to re-establish a semblance of it's original grind.

It's only over here that people almost obsessively sharpen Scandi ground blades at more or less the exact angle they are originally ground to.

I like Scandi knives. In fact, I like them so much that I make them, and I own and use several bought and traded with Norwegian makers when I've been showing over there, but I've yet to find any argument in favour of one grind being vastly superior to another. My own preference is for convex for a lot of reasons. It makes a tougher blade overall, disperses stresses more efficiently (more valuable on longer blades) and performs heavier cutting far more efficiently.

I also prefer it for personal reasons because I find it drop dead easy to look after.

As you say, my mileage is different, and so are we all

But at the end of the day, as I've often said, I'd be grateful for a piece of broken glass if the chips were down and I needed a cutting tool. We have the luxury of selection based on preference, and equipment to hand when needed. That is one of the fundamental differences between bushcraft and survival. The skills may have some crossover points, but the kit and situations don't.

It makes for interesting discussion though

 

[British Red]

Interesting - I'll debate it over a campfire with you some time. I guess our uses are probably different. I don't like batoning either (although I will confess to having done it a few times when camping out on pocket kit only to get at some dry wood inside wet wood when fire making or to start a split to continue with wedge and baton - that said a Mora was quite sufficient for the task). Funnily enough, most of my field knife tasks are carpentry of butchery though. Either way, as you say, the best tool is the one to hand (even a hollow ground one at a push ). My knife choices have always been personal. When I used to carry a single blade folder as a backup (switched to a Leatherman now), it was an unbelievably narrow blade. Caused a few raised eyebrows but it was amazing at fine work (remember tapping a tree with it once - bored the hole, and carved the gutter in a hawthorn branch to tap it with). Odd looking thing but it really complemented rather than replaced a fixed blade. I'm working on a new design just for me right now with a rather nice knife maker that will gibe me the "precision" I prefer. Suspect everyone else will raise an eyebrow, but time will tell

Look forward to the piccs

Red

 

[Andy]

Look forward to seeing the mods. We'll agree to disagree on the equality of convex vs flat I hope.
I personally am beginning to think theres a reason why almost every wood working tool and chefs knife in the world is flat ground.

I too look forward to seeing the mods you've made to an F1 blade, Even Peter who owns fallkniven said the F1 has more metal then he'd choose for his own knife but pointed out you can take away but can't put it back on.
Kitchen knives however work very very well with a full convex grind. I find a good convex edge knife will cut as well as a scandy or better once it's deeping in but is harder to control (something which is made much easier with my Guycep knife since it's thinner and very sharp indeed). Since I kitchen knife is normally cutting straight down this isn't such an issue, I find it means the edge is always kept fairly thin and quite to touch up with a ceramic hone (sharpmaker) and cuts as well as any other kitchen knife I've used. A convex grind on a global kitchen knife is a world away from the F1 though

 

[Ahjno]

You aren't the first mate - but, as I said, I have a problem with passing on bad blades - I dunno - I'll keep looking at it till I can think of what to do with it

Red

You shouldn't have
What about using the Lansky system? Seems a better option than re-grinding it free hand ... (that is if you can use the system for re-grinding).

 

[Stew]

Go for it Mark - it'll be interesting for you and us.

Admittedly, I don't understand why you don't sell them and buy something that suits what you want but each to their own.

What sort of angle will you go for?

 

[addyb]

I'm kindof on the fence here between a convex and a flat ground blade. It's almost as if I can't decide whether I want that extra edge strength that only a convex provides or if I want a bit more "sliceability" that is inherent with a flat grind. I'm not even going to touch on the Scandi grind subject because that's already been covered.

I will admit though, that back when I was teaching myself how to freehand sharpen like a pro (seriously, I'm REALLY good at it. ) I ruined a perfectly good SAK by accidently convexing only the edge bevel and not the entire blade. What I ended up with was a razor edge that rolled very easily. Live and learn!

My two cents,

Adam

 

[Andy]

It's almost as if I can't decide whether I want that extra edge strength that only a convex provides or if I want a bit more "sliceability" that is inherent with a flat grind.

if you get a convex grind as thin as a flat grind it will slice better. It might help to think of two ways to make a convex knife from a flat grind knife, one is to add bits of metal to give a nice round shape with a stronger edge, the other is to remove to corners between the edge bevel and the primary grind. The first one is the F1, teh second is the global kitchen knife. My dad always used to use a thick load of newspaper or leather with some wet and dry to remove metal behind the edge to make sure that the knives didn't end up with a thick edge which is the tendancy with kitchen knives. This was many years ago, since leather or newspaper doesn't bend as mucyh as a soft mousepad the amount of convexing was less (think a big wheel compared to a small wheel)

 

[addyb]

Thanks!

 

[jamesraykenney]

Sounds great mate - if you have a wee search around here, you'll find several more in the "don't like convex camp". I suspect its a bit like the down vs synthetic argument - its a personal thing. For me though - flat grind all the way!

Really love it if you would post how you get on as I am seriously debating throwing my F1 away since I don'y like it and its really bad wyrd to pass on a bad blade

Red

Not if you send it to an American...

I will even send you one copper penny to forestall the bad 'mojo' of giving a knife away...

 

[Shinken]

Xunil,

I guess it comes down to what you intend to use your knife for personally.

When i go on my lil wilderness trips 80% of the cutting my knife does is on wood. I make feather sticks with it, tent pegs, carve spoons, forks, butter knives, make pot hangers et cetera.

Now you can do all these things with Convex grind blades but for me scandi does them better. Also opinion seems divided as to how people traditionally used scandi grinds, i hear a lot of people say with a secondary bevel and maybe more say without a secondary bevel. More likely both were used and most probably both used succesfully.

My humble opinion of course