Thread: Sharpening setup

Just to add a bit more grist to the mill... I've recently been down this path and have now arrived at a situation where I can put a reasonable edge on a blade at not too great an expense. I use these components:

. Scheppach Tiger 2000 waterstone wheel (Tormek copy from Hare and Forbes - $149 on special)
. Honing guide (eBay $6)
. 150/600 diamond plate (eBay approx $80)
. 1500 Shapton waterstone (eBay $71)
. Leather Strop (eBay $7.15)
. Green Compound (eBay $3.50)

I use the Scheppach to create the initial bevel. This is easy to do and doesn't require any specific skill. I then use the diamond plate to refine the edge. Doing this freehand requires some skill but the honing guide makes it easy. I follow this with a polish on the Shapton stone. I use the metal ruler trick to put a micro bevel on the 'other' side. Then a further polish on the strop.

So all up it's been an investment of ~ $300 to give me an edge that's more than adequate for my purposes. I know some will say that 1500 grit is still too coarse, and it may be for some people, but I'm happy with it. I take comfort from Paul Seller's advice that for many years he only sharpened to 400 grit. If it's good enough for him then it's good enough for me.

Do diamond plates wear out? Well they certainly lose their aggressive cutting ability quickly but I've had mine for nine months now and still use it effectively on a daily basis. As far as I can tell it's flat. Is the Scheppach a quality machine? Absolutely not but it does the job reasonably well even though the stone needs replacing already ($55) and it's only a few months old. Sure I'd love a Tormek but I can't justify the cost.

The only other tip I've picked up recently was from a Youtube video about freehand sharpening. In the video the presenter did something I haven't seen anyone else do, he had the blade running north/south as he was using it on the stone. This allowed him to easily align the bevel to the surface of the stone but more importantly it eliminated the backwards and forwards rocking that occurs when I try to sharpen the normal way, which leads to a convex bevel. It may not work for everyone but certainly does for me.

Interesting. One of the questions I'm looking to answer is: How sharp is sharp enough? If you think 1500 is good to go it puts a new light on my question. I'd be really interested to hear what others think is 'sharp enough'.

Allow me to complicate things a little more with a question from Paul Sellers' blog:

"If the chisel on the left was sharpened to 250-grit, and it was, and it slices nicely across end grain pine like this, is that sharp enough?"

Chisel.JPG

If it does what you need it to do, then, by definition, it's sharp enough.

Originally Posted by Tccp123

"If the chisel on the left was sharpened to 250-grit, and it was, and it slices nicely across end grain pine like this, is that sharp enough?"

the answer is NO! it is not sharp enough because it won't be able to split an atom, and you have to account for every possible use that the chisel may encounter even if your "plans" say to pare end grain pine. who knows what could happen, plans change all the time.


ps. if it's good enough, then it's perfect.

Originally Posted by rob streeper

Interesting. One of the questions I'm looking to answer is: How sharp is sharp enough? If you think 1500 is good to go it puts a new light on my question. I'd be really interested to hear what others think is 'sharp enough'.

it depends on what you are doing with the edge tool.

The other day I heard the opinion that cutting edges used to produce show surfaces need to be much sharper than those used for non-show surfaces. The example was a router plane blade used to excavate a trench, and a smoothing plane blade. I'm not sure I agree as sharpness also impacts on the level of effort required to sever wood fibres.

I think a better way to put the question is how fast can you get to "sharp enough". I can get from picket edge to sharp enough in about three to five minutes which is good enough for me. That is from a grinder to two stones to green honing. Refreshing the edge takes about 30 seconds, certainly under a minute.

Originally Posted by Tccp123

Allow me to complicate things a little more with a question from Paul Sellers' blog:

"If the chisel on the left was sharpened to 250-grit, and it was, and it slices nicely across end grain pine like this, is that sharp enough?"

Chisel.JPG

250 grit what?

Norton Abrasive's 2015 Industrial catalog suggests that cotton fibre impregnated with 120 grit is good for polishing stainless steel.
Elsewhere in the catalog, Norton suggests that their Fine India oil stone (at about 340 grit or P400 or 35 micron) is equivalent to a 4000 grit water stone.
and Norton's Medium India stone at 240 grit is equivalent to a 1000 water stone.

so 250 grit without additional information doesn't tell us much

Originally Posted by ian

250 grit what?

Norton Abrasive's 2015 Industrial catalog suggests that cotton fibre impregnated with 120 grit is good for polishing stainless steel.
Elsewhere in the catalog, Norton suggests that their Fine India oil stone (at about 340 grit or P400 or 35 micron) is equivalent to a 4000 grit water stone.
and Norton's Medium India stone at 240 grit is equivalent to a 1000 water stone.

so 250 grit without additional information doesn't tell us much

I think the grit size is irrelevant in this example, that's just a furphy. What he's asking is if the chisel can take very fine shavings off end grain pine is it sharp enough. In other words if the tool can demonstrably do the job asked of it isn't it irrelevant what sharpening method produced that result?

What I've found is that most chisel blades can take a fine edge but only a few can keep it in use. All of the chisels are from reputable vendors and have more or less good reputations so I assume that the bulk of users of the various brands I've tested are satisfied with the respective edge holding abilities of their tools only because 1) I haven't read critical comments on the 'net and 2) The prices, and therefore (I assume) demand, for these brands are respectably high.

I have a lot more work to do on this study but it won't answer the question of how sharp is sharp enough thus I'm interested to hear opinions from all who care to offer them on the issue.

Originally Posted by rob streeper

I have a lot more work to do on this study but it won't answer the question of how sharp is sharp enough thus I'm interested to hear opinions from all who care to offer them on the issue.

Ask our mate knifegrinders, I'm sure he could tell you in BESS

Originally Posted by elanjacobs

Ask our mate knifegrinders, I'm sure he could tell you in BESS

That system won't give the answer I'm after.

Originally Posted by Tccp123

Allow me to complicate things a little more with a question from Paul Sellers' blog:

"If the chisel on the left was sharpened to 250-grit, and it was, and it slices nicely across end grain pine like this, is that sharp enough?"

Chisel.JPG

Makes me question a lot of the buzz around sharpening stuff.

Originally Posted by rob streeper

Makes me question a lot of the buzz around sharpening stuff.

Now you've hit the nail squarely on the head!! Paul Sellers briefly touches on this when he distinguishes between those who sharpen so that they can cut wood and those who sharpen so that they can say "I have the sharpest blade"

Nothing wrong with either motivation... just saying.