Looking for an easier way to flatten the back of plane irons

[Rafael Herrera]

Last night I cleaned up and restored a 2" iron for an Stanley jack plane. Although I've used the method suggested by David, with good results, this time I used a double sided fine/coarse crystolon bench oilstone. It didn't take very long to get a decent face. The bevel and edge squareness needs a little more work, though. I think it spent about half an hour to prepare the iron and the chipbreaker.

[Andrew Pitonyak]

I generally use a magnet when I want to flatten the back of a plane blade. Lookup Magswitch Magnetic Jigs

Works well to hold the blade so it is not hard on the fingers.

[steven c newman]

Ok.....Not sure how ham-fisted others are around their grinders. Do they press as hard as they can against a wheel.....hoping for a failure?

This is the grinder I have, and use...
The Grinder, flattening a back.JPG
Still has the wheel it was sold with, BTW. The grip I use?
The Grinder, The grip.JPG
I press DOWN on the rest....NOT against the wheel I want a light, vertical rubbing going on. In, back out, check...repeat until done....fingertips will also inform me IF things are getting too warm, and needs a quick dunk. The iron being flattened in this photo is a 2" wide Defiance iron.....

Results?
The Grinder, ready to polish.JPG
Back is now flat, and ready to polish to whatever level one wants....in my case, that would be around 2500 grit.

Counting walking to the shop, setting up, flattening AND polishing....AND walking back to my computer.....time? 10 minutes.....YMMV.

Iron had a hollow centered in the middle, just behind the edge....Bevel is a single one, at 25 degrees. There is now a nice bald spot on my left forearm....

[Andrew Hughes]

Nobody doubts you use this method Steve. Others passing through might read your post and try it on a totally different grinder maybe with a defect. And lastly without the skills you have.
We have to consider others.
I stand by my post using the side of high speed grinder is a lot like poking at a hornets nest.

Good Luck

[J. Greg Jones]

For others passing through, and to support Andrew’s comment, grinding on the side of these wheels is highly discouraged by the manufacturers because of the risk of wheel breakage.

https://www.nortonabrasives.com/en-u...rinding-wheels

[Alan Schwabacher]

I've thought the CBN wheels with a wide swath of grit on the sides (Woodturner's Wonders mega square, for example) might be well suited to flattening plane iron backs, but I've not seen anyone who has one comment on that.

[Ray Bahr]

Hi All,

Couple of thoughts, and apologies if stating the obvious:

Keep the speed down, really really important to not get things hot
Don't flatten the entire back, no need to
I recently picked up a Worksharp 3000 and some diamond disks similar to what is use by jewlery folks, etc. I got some from https://www.ebay.com/b/Craft-Glass-G...44/bn_16515001

Seem to work. I have also used DMT and sandpaper. There is no 'easy' way.

Ray

[Rob Luter]

Ok, that would be easier on my fingers, but how do you prevent the iron secured to the underside of the piece of wood? Maybe hot-melt glue?

Double backed tape. It works great.

[steven c newman]

Couple of items I should point out....just in case some can not read....

1) ALL pressure is down onto the tool rest. It is not like I am jamming the iron into the side of the wheel....

2) I slowly rotate the iron to the wheel, lightly touching. After all, what's the hurry? A light touch is all you need.....

3) Raise some sparks, pull the iron back out, check the progress...repeat as needful......process might take 5 minutes....if that....then go to your favourite stones, and polish as needed.

My left hand was running the camera for the photos....otherwise, it is the one rotating the iron to the wheel's side. The right hand's job is to keep the iron vertical, and pressed down on the tool rest. Fingertips to tell me when the iron is getting a bit warm, and needs a dunk in the cup of water.

I also have a disc/belt sander...that I can use for the same operation...however, not everyone out there has such a machine.....but, they usually will have a grinder. And IF they take care of that grinder, and have GOOD wheels on board. I suppose there are some out there that will get in a big hurry, jam that metal as hard as they can against the side of the wheel.....one, you WILL burn that steel, two, the grinder WILL throw the iron right back at you for doing such a stupid thing...way before the wheel would break.....unless the iron gets caught somewhere inside the grinder. Which is why the "Ham-fisted" remark....

That's ok, go back to those hours of sheer drudgery flattening the back of an iron on a stone.....Then complain because the stone is no longer flat.....


You could buy a 1" x 30" belt sander....make sure the table and platten are 90 degrees to each other....and go that route....it will work, IF you can also KEEP the iron at 90 degrees to the table. Too good a possibility of the iron leaning a bit in or out....I tried this ONCE....was not worth the effort.

[J. Greg Jones]

I can read, and comprehend, just fine. The manufacturer states one of the steps to avoid wheel breakage and injury is ‘Don’t grind on the side of the wheel.’ It doesn’t also say, ‘unless you grind on the side of the wheel like Steven does-then you will be fine.’ Grinding on the side of the wheel is an unsafe practice. If it works for you and you are ok with the level of risk, carry on. However, it is an unsafe practice and to promote it in a public forum without acknowledging the risks as stated by the manufacturer, is just irresponsible.

[Andrew Hughes]

Well said Greg. One problem with giving advice is we never know how far someone will take it. For instance developing a skill doing something that has grave consequences.
Don’t take it personally Steve. We all do stuff that not to be passed on.
I myself have practiced the safety squint too many times. When I’m too lazy to find my glasses.
I fully know and understand if you hang around the barbershop long enough your bound to get a haircut.
Are we cool?
Good Luck Always

[Jim Koepke]

Grinding on the side of the wheel is an unsafe practice. If it works for you and you are ok with the level of risk, carry on. However, it is an unsafe practice and to promote it in a public forum without acknowledging the risks as stated by the manufacturer, is just irresponsible.

People should be careful about mentioning procedures including practices to be deemed unsafe by conventional wisdom. There are many people new to the field who may not have learned safe practices or how to be careful in various situations.

At one time it was common for me to mention shaving arm hair to test a blade's sharpness. Another member brought up the point of how this can be very dangerous. Those of us who use or have used a straight razor to shave know the techniques involved to not draw blood.

Anyway due to the concerns of another over the safety involved in my method of sharpness testing it is now seldom mentioned.

Another point people would be surprised to learn is how many woodworkers do not have a grinder in their shop.

jtk

[J. Greg Jones]

People should be careful about mentioning procedures including practices to be deemed unsafe by conventional wisdom. There are many people new to the field who may not have learned safe practices or how to be careful in various situations.

At one time it was common for me to mention shaving arm hair to test a blade's sharpness. Another member brought up the point of how this can be very dangerous. Those of us who use or have used a straight razor to shave know the techniques involved to not draw blood.

Anyway due to the concerns of another over the safety involved in my method of sharpness testing it is now seldom mentioned.

Another point people would be surprised to learn is how many woodworkers do not have a grinder in their shop.

jtk

Jim, your analogy is seriously flawed. This is not about ‘technique’. Sure, people can shave arm hair successfully to test blade sharpness. People can also use a table saw without a blade guard or splitter and never have an injury as a consequence because they have developed a ‘technique’ that serves them well. There is no ‘technique’ that prevents a grinding wheel from flying apart if one ignores the manufacturer’s instructions to not grind on the side of a wheel not designed for that purpose. It happens. I’ve seen it. I had to file the worker’s comp report to get my employee’s injuries reimbursed. No amount of ‘technique’ is going to overcome some instances of ‘stupid’.

[lowell holmes]

I have diamond hones and use them to flatten and sharpen chisels and plane irons. I have three hones with progressive coarseness.

[James Spangler]

FYI, I did try Steven's suggestion yesterday. I have a Rikon slow-speed grinder with a 150 grit wheel and very gingerly used one side to lap an old plane iron. I ended up with the edges worn back more than the middle, and I was careful to put only slight pressure at the center of the blade. So dangerous or not, it does not work for me. I also checked the platen on my old belt sander and verified that is is indeed not flat across, so not worth revisiting it to flatten irons.

There is a Woodcraft store and a Rockler store within driving distance from me. If I happen to get a coupon from either, I may go there and buy a Work Sharp 3000. Not in a big hurry, but still a consideration.

Thanks again to everyone who responded.