Flattening back of plane blade

[Roger Nair]

What I have done with success is to alternate with a coarse diamond bench stone, to define the high spot, then go to the bench grinder or better yet a die grinder and LIGHTLY grind the high spot only and return to the bench stone for a nice long session, then repeat as necessary. Never bear down when power grinding and never go near the edge and keep the blade cool by using the mass of the blade to absorb the heat, the edge and sides are low mass areas. If you feel the blade heating up a little, you have to stop grinding. If you feel the need to quench, then you have ground the blade too aggressively. By alternating you can speed up removal greatly but aggressive dry grinding will result in harm to the blade.

[Robert Hazelwood]

Fresh 80 grit sandpaper will cut much faster than any diamond stone I've used. But keeping it fresh is important- you can remove more material in the first minute or two of use than you can in the next 10 minutes. So try to arrange the paper you stick down so that you can use every bit of it, and once every part is used don't hesitate to change it.

The prominent hump makes things more challenging. The safest way to lap is to only go in one direction instead of back and forth, and don't try to go too fast. You want to keep the pressure centered over the hump, and you do not want to let it rock side to side about the hump. Once you can develop a decent sized flat spot on the hump, that will sit stably on the lap surface, you can try going back and forth and increasing your speed.

Once I've gotten the back flat with 80 grit, I use some worn out section of 80 grit to remove the deepest scratches, then move onto 220 grit sandpaper. Then onto a 1000 grit waterstone, and arkansas stones after that.

[ken hatch]

At some point you should say to heck with it and buy a new Japanese, Hock, Veritas, or even a new Stanley cutter and get on with life. Unless rubbing iron on sandpaper or stone is how you get your jollies there are better ways to spend your time in the shop.

Of course YMMV,

ken

[David Bassett]

... there are better ways to spend your time in the shop....

Yeah! You could be building another bench!

[ken hatch]

Yeah! You could be building another bench!

David,

You have been reading my mail .

My next build is a kick wheel for MsBubba. After that is a toss up between a tarted up shave horse (my current one is a prototype and pretty ugly) or a new bench with an Oak base and slab TBD. Whatever life is too short and there are too many options with respect to cutters to spend hours rubbing iron on stone unless the cutter is a really old forged steel that shouldn't/or can't be replaced.

ken

[steven c newman]

Don't need to be a Blacksmith with the hammer. Instead, use the same amount as you would use on a handsaw plate.....

I usually use the ball end of the hammer....if the iron "hops" went you hit it, back off a bit on the swing. You are not trying to do a horse shoe operation....think of it as more of removing a dent in a fender....

All that sanding to get a perfectly flat back on the iron....results in a thinner iron, ..unless you are simply looking for an excuse to go out and buy a new iron ( that costs more than the plane your are working on..)

Been rehabbing planes for a long time....and I go with what I find to work best.
Defiance No. 3, tear down 3.JPGtoDefiance No. 3, clean up 2.JPG
Both needed flattened...once the crud was removed...Spent about 2 hours or so, not counting the PBlaster soaking...
Defiance No. 3, assembled, side.JPG
Once the bolt for the rear handle is repaired, it is ready to go to work...

[justin sherriff]

I got the back flattened now.
20190910_192803.jpg
I still need to spend some time on my 8000 grit.
Hammered down the hump and then I grinded about 1/8 to 3/16 inch off the end to get to the nice flat I had.

A quick sharpening and was making nice shavings.
20190910_193953.jpg
so far I am liking the feel of the #3 vs a big #4 1/2

[Steven Mikes]

I'm with Steve Newman on this one. Actually I don't even have a ball peen hammer, I just used a soft-faced hammer (one of those yellow/red ones). Paul Sellers has a video somewhere doing this, I recommend it. He puts the plane blade on a piece of softwood (pine) and whacks it on the high spot a few times. The pine has enough give to allow the metal to flex. You stop when you end up with a very slight convex surface on the back. Worked great for me.

[Jim Koepke]

so far I am liking the feel of the #3 vs a big #4 1/2

The #3 is a nice sized plane and gets used more than my #4-1/2. The bigger plane is handy when knocking down a large hump on the face of a board or panel.

jtk

[Doug Dawson]

I just picked up an stanley no3. I am trying to flatter the back of the blade and it is going slow.
Here you can see the high spot in the middle if that was a hollow it would of been a easy job.
Attachment 415781

how should I go about getting this thing flat? Is there a short cut or is ti just going to be a long time at the diamond stone.
I have a coarse diamond stone, 1000 and 8000 shapton stones.

You could try shaving it off with a sharp carbide scraper. Blue up the back to check your work, and repeat as necessary. Me, OTOH, I'd just buy a replacement blade (not necessarily new BTW) and go on about my way.

[Charles Guest]

At some point you should say to heck with it and buy a new Japanese, Hock, Veritas, or even a new Stanley cutter and get on with life. Unless rubbing iron on sandpaper or stone is how you get your jollies there are better ways to spend your time in the shop.

Of course YMMV,

ken

Yes! After having read the responses in the thread it's just bizarre that people would go to the lengths they go to for a cutter easily replaced. I get the mental image of wailing and the gnashing of teeth over a bellied cutter, all in the midst of thousands of dollars in other woodworking equipment, and some extraordinarily arbitrary line being drawn in the sand. It doesn't make sense. It's a Stanley plane iron, made in the hundreds of thousands if not millions, it's not a vintage Aston Martin.

[Derek Cohen]

I agree about getting a new blade. Frankly you really could upgrade your plane by getting a PM-V11 blade. Over at WoodCentral Hand Tools forum David Weaver has been describing his exhaustive testing with a series of steels, and PM-V11 came out on top ... not just for being longer lasting, but producing a better finished surface than all other steels.

Regards from Perth

Derek

[steven c newman]

These last 3 posts sound more like a "Message from our Sponsors"......OP has already FIXED his iron....

[ken hatch]

These last 3 posts sound more like a "Message from our Sponsors"......OP has already FIXED his iron....

Steven,

If you go back and read the original post that the last few posters were responding to it was posted well before the OP posted he had fixed the problem. I stand by my post, there is no "Message from our Sponsors". Unless you just enjoy rubbing iron on stones there are better ways to spend your shop time with little cost, replacement cutters are cheap, much cheaper than my time.

ken

[david charlesworth]

I think we should be much more willing to send back any blade or chisel which has belly, in width or length, to the vendor or manufacturer.

It can be a huge amount of effort try and correct this fault.

I had a student once who came with a set of Sorby chisels. All had belly in the length. We had to send them back twice before the problem was dealt with.

It was only after I had spoken with the workshop foreman that anything was achieved.

Best wishes,
David Charlesworth