Grinding plane irons square and straight?

[LuptonM]

Can anyone advise me how I might grind plane irons on a dry bench grinder so the blade is straight and square ready for honing?

 

[Jacob]

Can anyone advise me how I might grind plane irons on a dry bench grinder so the blade is straight and square ready for honing?

What is the problem exactly?
You check with a square to see where there is too much metal, and remove the excess. If the blade is not parallel sided you'd use an adjustable bevel instead.
I wouldn't necessarily do it in one, but instead just bias my honing pressure to remove more from one side than the other, until it comes out right after several sharpenings.
I don't do "square" for most plane irons, but the idea is the same for a camber.

 

[studders]

I tend to do it by eye and adjust the angle of presentation to the grinder accordingly.

 

[OPJ]

Do you have a table or tool rest with your grinder? Something like this. That's one of the easiest ways to get accurate and repeatable results.

 

[Jacob]

Do you have a table or tool rest with your grinder? Something like this. That's one of the easiest ways to get accurate and repeatable results.

True no doubt, but for a practical working/sharpening regime, accuracy and repeatability are not priorities.
Freehand can be somewhat variable, but is very effective nevertheless.

 

[LuptonM]

Well I have this grinder http://www.axminster.co.uk/axminster-ax ... rod781392/

Initially I thought as a beginner using a wetstone wheel with the jig would be a good idea to get good results. However I find it takes too long but the main problem is that it adds quite a large chamfer to the blade which isn't very good for chisels nor for smoothing planing irons (I am right that smoothing plane irons need to be pretty straight?)

So I wish to use the dry grinding wheel especially as it will save time restoring chisels and plane irons I find at carboots. However the tool rest on the dry grinding wheel is a little useless since plane irons are much wider that it, making free hand grinding hard to control.

So basically I want a reliable way of grinding chisels and plane irons straight and if I want to add chamfer to the blades I can choose to do that myself

Do you have a table or tool rest with your grinder? Something like this. That's one of the easiest ways to get accurate and repeatable results.

Have u tried the veritas tool rest (and maybe the jig that goes with it)?

 

[Jacob]

.....
So basically I want a reliable way of grinding chisels and plane irons straight and if I want to add chamfer to the blades I can choose to do that myself....

Car boot stuff I usually start by honing at 30º (same as what crazy sharpeners might call "applying a 30º micro secondary bevel") just to see how it comes out. If the blade was already in good nick then that's it, all you need.
If not good then the position of the shiny new bevel shows what you need to do next e.g. if the new bevel has a lot of untouched steel between it and the edge then it has been dubbed over and might need grinding. I'd do it all by hand but if a lot of metal needs removing I'd do it on a belt sander 60 grit, freehand again.
Basically all hand and eye, and a lot quicker and easier than ferkin about with jigs, rests etc. Also removes least metal so your blades last a lot longer.

Have u tried the veritas tool rest (and maybe the jig that goes with it)?
Certainly not, wouldn't dream of it, why bother? :lol: :lol:

 

[studders]

I use this one.
Does the job OK though I binned the silly tool clamp thing and glued a bit of hardwood to the grinding platform to make it bigger and more stable.

 

[Alf]

I use the Veritas tool rest - works okay. Wouldn't bother with the jig; better to use your eyes to see where you need to grind than blindly follow the jig, in my experience. (Embarrassing and ancient YouTube vid here, if it helps. Pardon the parrot.) Also you need to keep a light touch on the wheel to avoid over-heating, and the jig in the track just stops one easily removing the steel from the wheel. Nice in theory, not so good in practice.

 

[Paul Chapman]

I'd persevere with the wet grinder if I were you - it's so easy to burn and ruin blades on high-speed grinders. Many people seem to complain that wet grinders are slow but I find mine (a Tormek) is fast. Are you pressing hard enough?

Cheers :wink:

Paul

 

[bugbear]

..it adds quite a large chamfer to the blade

I think you've become confused. You're using "chamfer" to mean "camber".

They're not the same thing at all.

Moving on...

Grinding a straight and square edge is fairly easy. Just mark a line on the blade, and work to it. Since metal is removed slowly (even with a power grinder) it's easy to be accurate.

To mark the blade, either use a carbide scribe, and make a scratch, or coat the blade in engineer's layout blue (or marker pen...) and use "anything pointy"

BugBear

 

[Jacob]

..it adds quite a large chamfer to the blade

I think you've become confused. You're using "chamfer" to mean "camber".

They're not the same thing at all.

Moving on...

Grinding a straight and square edge is fairly easy. Just mark a line on the blade, and work to it. Since metal is removed slowly (even with a power grinder) it's easy to be accurate.

To mark the blade, either use a carbide scribe, and make a scratch, or coat the blade in engineer's layout blue (or marker pen...) and use "anything pointy"

BugBear

Or just draw a line with a felt tip pen.

 

[LuptonM]

I'd persevere with the wet grinder if I were you - it's so easy to burn and ruin blades on high-speed grinders. Many people seem to complain that wet grinders are slow but I find mine (a Tormek) is fast. Are you pressing hard enough?

Cheers :wink:

Paul

It really is slow- can take me more than half an hour even if the blades in good condition
I don't think its that easy to ruin blades if you dip the blade in the cup of water often. I've seen my dad overheat a blade but he's not careful- the metal is left with a blue (sort of oily) looking patch

I use the Veritas tool rest - works okay. Wouldn't bother with the jig; better to use your eyes to see where you need to grind than blindly follow the jig, in my experience. (Embarrassing and ancient YouTube vid here, if it helps. Pardon the parrot.) Also you need to keep a light touch on the wheel to avoid over-heating, and the jig in the track just stops one easily removing the steel from the wheel. Nice in theory, not so good in practice.

hand grinder is seriously cool but I bet its slow (though maybe not as slow as my wetstone grinder-it turns 90rpm)

A belt sander's a good idea jacob since its easy to get a blade straight but I've already bought a grinder. Carboot tools usually come pretty rough with blades ground incredibly badly

I'll think I'll save up for the veritas tool rest (without the jig) and grind freehand.

I wonder if grinding it could be like using a turning chisel on a lathe. My dad's got a small lathe and you can use the groove (running your finger along it) in the toolrest as a guide to get the wood all the same thickness.

 

[bugbear]

To mark the blade, either use a carbide scribe, and make a scratch, or coat the blade in engineer's layout blue (or marker pen...) and use "anything pointy"

BugBear

Or just draw a line with a felt tip pen.

Accurate marking out is a good basis for subsequent work.

I suppose if you're in a real hurry, you could just freehand/eyeball squareness.

Not my style though.

BugBear

 

[OPJ]

Have u tried the veritas tool rest (and maybe the jig that goes with it)?

Yes, I used to own both and they were a bit cheaper back when I bought mine... That was until I sold my grinder and bought one of these instead! :wink:

It does everything I need with ease and accuracy. My grinder setup, even with the Veritas accessories, was never this quick and easy. There's little mess, a minimal amount of sparking and a very low risk of over-heating the steel.

 

[LuptonM]

To save me buying something do u think I could use a hand held belt sander in some way (maybe mounted upside down) to grind tools?

 

[Jacob]

To save me buying something do u think I could use a hand held belt sander in some way (maybe mounted upside down) to grind tools?

Sure can, and much better than a grind-wheel; flat bevel, runs cooler, wider than any plane iron. I grind with 60 grit.
Also you can use it for sanding wood!
I've got a bench grinder and an angle grinder but they are for metal work, not for sharpening* - except spindle profiles.

*PS edit...metal work other than sharpening.. (for Alf see below)

 

[Alf]

Fascinating. What's sharpening if it's not metal work? :?

 

[LuptonM]

To save me buying something do u think I could use a hand held belt sander in some way (maybe mounted upside down) to grind tools?

Sure can, and much better than a grind-wheel; flat bevel, runs cooler, wider than any plane iron. I grind with 60 grit.
Also you can use it for sanding wood!
I've got a bench grinder and an angle grinder but they are for metal work, not for sharpening - except spindle profiles.

The belt sander is like this one http://cgi.ebay.co.uk/CLARKE-BELT-SANDE ... 23ffe90036
accept its made by nutool.

The problem with my idea is how to hold it upside down and stop it moving

I am really going have to think about it. I wish I had got my dad to get this (http://www.machinemart.co.uk/shop/produ ... -sanders-2) instead of a bench grinder. I may end up forking out for one of these in the future instead if I can't get my idea to work-

For a noobie, when it comes to buying equipment its like a jungle out there. Companies are always making u want something u'll never need
At least I think I got my honing equipment right the first time

 

[Jacob]

....
The problem with my idea is how to hold it upside down and stop it moving

Some of them come with brackets so you can turn them upside down or hold them in a bench vice. If not then it's not difficult to make something up. I've got the posh Bosch which sits upside down quite easily, but has brackets too, for horizontal and vertical mounting. That Clarke looks a big bu***er maybe more than you need, but I don't know anything about it.

..
For a noobie, when it comes to buying equipment its like a jungle out there. Companies are always making u want something u'll never need

Abso bloody lutely! Don't buy anything!

At least I think I got my honing equipment right the first time

Er - except you don't need any equipment for honing (except an oil stone). We all get taken in at some point by the sales pitches!