Here's an interesting philosophical question

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

johnelliott

Established Member
Joined
16 Apr 2003
Messages
1,105
Reaction score
0
Location
Near Swindon, Wiltshire
I expect we've all had to deal with this one- one has a tool and it is new and sharp. Could be the blades in one's planer thicknesser, perhaps the blade on a table saw, maybe even a decent TCT router bit.
Anyway, as I was saying, it starts off new and sharp. One uses it, perhaps a lot. Eventually it starts to become less sharp. It still works, still gets the job done, but not quite so well, a bit slower, the usual blunt tool symptons start to show themselves.
Now, the big question- at what point does one say, time to invest in a new blade or having this one sharpened?
I'm not looking for advice, BTW, just interested in other peoples' viewpoints

John
 
John,

The right answer should be when the bluntness of the blades etc either affect the quality of the work or compromise user safety.

For me, it all depends on what I using and using it for.

Bandsaw blades; I run them into the ground because I think I don't have the time to keep changing them! When I put a new one on I think how beautifully it cuts. Table Saw blades; the same! Router cutters; I make sure these are in optimum condition and change whenever necessary.
Dowel Bits; I virtually use a new one on each job! All hand tool blades; I keep razor sharp at all times.

I dont have a planer, thicknesser but if I did, this is one set of blades I would keep pretty sharp. In fact my machinery needs are pretty low, so for me its an easy question to answer!

Why the question, just out of interest?! I'm sure answers give alot away on peoples way of working and attitude to the work!!

Regards
 
Planer blades are a good example of the problem. They can take some time to remove, but fitting the new or reground ones can take ages, due to the time and care needed to get them absolutely right. Much easier to leave them in. Got to be changed eventually, but eventually is a bit vague, isn't it?

The reason for posting about this is that it's something I think about while I am working and I wonder if others think about it too

John
 
My answer is keep 'em sharp. The time you take sharpening and setting up is more than offset with the time and grief it takes to do a job with blunt blades. That said there's nothing as sweet as working with real sharp tools. That pleasure alone makes it worthwhile. Also I took on the advice of a tech lecturer the hard way as a young lazy app, " sharp tools do the job you want, it's only blunt tools that cut you." :oops:

Drew
 
I'm not making myself sufficiently clear.

The difference between sharp and blunt tools is fairly obvious. However, the progression from sharp to blunt is obviously a slope, my question is whereabouts on that slope does one say that the time for re-sharpening (or replacing)and all the time and hassle involved has come?

John
 
Smoke billowing from your machine (or out of the top of your extractor) is a good sign that your blades need sharpening. :twisted:

Just joking. As soon as you feel more than the normal resistance, get em sharpened.

Doughnut

P.S. A diamond hone works wonders for tickling up router cutters and planer knives.
 
i`d say its probably horses-for-course, it depends on what job your trying to achieve.

i.e. if your ripping out some rough sawn then prehaps you don`t need your table saw blade to be 100%

but if your trying to use your router table as a joiner (a-la-norm) you probably want your spiral-straight-cutting bit to be as sharp as possible.


I think everybody probably has a "importancy" list in thier head of how sharpe tools need to be, some people probably sharpe everything when it starts to get dull, some probably leave some tools on the "dullness curve" for longer than others.

I bet there is an interesting relationship between experience and tool-sharpening tolerence. (i.e. the more experienced you are, the shorter time you leave tools between sharpening).
 
It is an interesting question and one that I do think about. If I am just doing odd bits and pieces, ad hoc, and I think a tool is starting to need sharpened then I probably wouldn't do it then, unless it was something like a router bit that takes seconds to change. Hand tools only take a few minutes to sharpen so chisels and plane irons get done at the time.

If I am setting up to do a larger project then I would make sure everything was nice and sharp from the start, likewise if it is something that relies upon having a very good finish then I would sharpen or replace before I start.

I have to be honest and say I nearly always end up buying new blades and not having blunt ones sharpened, but this is rather wastefull.
 
I bet that if someone invented throw away planer blades that were cheap to buy, very quick to fit, and did the job as well as traditional ones, we would all be changing them 3 or 4 times as often as we do now.

If this is so, it suggests that planer blades are never changed when they should be!!
 
Just Briefly John

If their good Blades then get them Sharpened every time, Thats why you pay for good blades the steel is good and will sharpen up as good as new. The guys that sharpen Router Blades and Spindle blades will soon tell you when they are shot.
 
where i come from, we hone our planer blades between grindings while they are still in the machine :shock: . does anyone else??
 
Doughnut,

Yep, me too. Got one of those little diamond honing whatsits, and as long as you concentrate you don't lose too much blood... :shock: :wink: I can never get the edge as good as when they're fresh from the saw doc though. :roll:

Cheers, Jester
 
johnelliott":zmvjraci said:
I'm not looking for advice, BTW, just interested in other peoples' viewpoints

John

A quote from my opening post. I suppose forums are very much like normal conversations, people often don't really hear what the other person is saying.

John
 
Just a general point here,

When I reply to posts on these forums I cant refer to previous posts while I type my own! Probally there IS a way of doing this but I havent been told. Consequently, its near impossible to accurately refer back to original points and as the posts change slightly as they go on I end up sometimes talking about something completly different to what was requested in the first place!!!

Regards
 
yes John

And my viewpoint is that you should hone planer knives while they are in the machine to keep them in top condition between grindings.
 
Well my view is that it doesnt hurt to spend a few minutes honing up between sharpening to givew a decent finish, after a few honings maybe then its time for a resharpen. Had anyone considered that the extra friction caused by dull tools may cause extra strain on the motors and shorten the life of the machine? Just a thought :idea:
 
If honing keeps blades in top condition, why would they need grinding/sharpening?

I do agree that dull tools should be sharpened, BTW, in fact that seems pretty obvious to me

John
 
johnelliott":2q10fsd8 said:
If honing keeps blades in top condition, why would they need grinding/sharpening?
John

John,
Normally edge tools have two angles on them, one ground the other honed. The more you hone the wider the second angle land becomes. Thus you are trying to remove more metal with the honing, which takes longer and is slower. :(
The regrind on a wheel or stone restores the first angle removing the land caused by honing, therefore honing becomes a quick :D way of restoring the edge again and the cycle continues hone, hone, hone, sharpen :!:
 
Back
Top