Thread: Trying to flatten a plane blade

Tiger.....Rather than spending all that money on diamond stones etc to try and flatten a useless blade, why no go out and buy a good Hock or Rob Cosman blade....you will be amazed at the improvement.

Cheers

John M

Originally Posted by ravna

Tiger.....Rather than spending all that money on diamond stones etc to try and flatten a useless blade, why no go out and buy a good Hock or Rob Cosman blade....you will be amazed at the improvement.

Cheers

John M

Funny, the standard Record blade in my #4 is the same thickness as the Hock that's actually in the plane right now, and the Record is plenty hard all on it's own.

I don't think the Hock iron is going to make much, if any improvement.

Not that I ever had a problem with the old Record iron myself anyway...


Tiger, put a back bevel on the blade and be done with it, please. Flat backs are not even the slightest bit essential to a properly working plane. Maybe they're nice to have, maybe they save some trouble down the track when sharpening but there is no good reason to chase one down and you can get there without spending any effort at all.

Flatten what you can, spend no more than 5 minutes on it. Take note of where it's flat, and then put a slight bevel on the back of the blade so that you have a nice, sharp edge all the way across. Once you start running into the flat area on the back as you wear the iron out, then you get your flat back, no extra effort required.


If you're adamant about getting the back flat however, I can help there as well.


(In case you didn't know, I sell waterstones, diamond plates and soon, replacement irons for iron planes.)

Stu.

...put a back bevel on the blade and be done with it, please. Flat backs are not even the slightest bit essential to a properly working plane

so long as you achieve a 'polished back meeting a polished front bevel' by polishing a back bevel.

Sorry, thought I'd throw that in... pedantic terminology which may be useful to some.

If the corners of the back of the blade are hollowed, back beveling will still take some time. If the stone is wonkey... then the same problem (of the stone being wonky) will raise its head.

Tiger talks about flattening the corners... if this means that the back of the blade has been 'dished/hollowed' at the corners (and I've noticed this several times on old secondhand blades... I put it down to a misinterpretation about 'rounding the corners of a blade'), then a regrind of the edge may be needed. A quick grinding method (not necessarily needing a bench grinder) may be needed, and a diamond stone may be of benefit. A fast cutting diamond stone or combo may be ideal, particularly if it can be multi-roled for all other edge cutting tools and also for rehabbing, such as for chisels.

Rsser did a lot of testing when his arm was laid up... seem to remember he was posting detailed results... ??

Regards flattening a waterstone - despite being informed many times that granite offcuts and mdf is not 'flat', I still use a plasterboard 'sanding mesh' on granite/kitchen benchtops/mdf to flatten waterstones... but I don't seek perfection, only planing results as measured by touch and 'results after finishing', not microscopes and micrometers.

However, a shaving that can only be measured by a micrometer, read under a microscope is cool to read about.

Question:
Is there a fast cutting stone, able to stay flat, for fast and dirty flattening and material removal, which fits into the typical 'medium and then fine' waterstone sharpening regieme?

Sorry Tiger... not so much as a hijack as a lobb back into Schtoo's court ('cause he has very relevant experiience here due to his sharpening experiments.)

Sorry Schtoo...but please provide an answer 'cause your sharpening experiments and attention to detail could help a lot of us out and I think the answer lies in the stock you sell!

With best intentions...

Thanks guys for your thoughts. Schtoo glad that it's not just me with these Record plane irons, they are hard. I remember I did another one of these and it also had high corners but it was not as bad as this one.
Not much comment on the diamond stone but I think I'll get one, I've done most of my sharpening on a Bear oilstone which cuts well but have been unable to flatten it properly. Just have to decide what size to get but I would like to do plane irons on it.

I have two more possible explanations for the jamming, that I have experienced in the past.

One is that if the blade have been flattened on a hollow stone by the previous owner, there will be a small curve to it. If you put that on a flat stone and put pressure on the sides with your fingers, because it's so thin it will bend and lie flat on the stone, but when you take your fingers off, the blade will flex back into the curved possition it had before. When you look at the scratch marks it will look flat, but it's not. To correct it you will need to only use one finger in the middle of the blade to establish a new flat surface.

The other thing I can think of is how you have flattened the chipbreaker. If you put it flat on the stone, the flat surface near the cutting edge will be straight with the edge of the top end. That way, when you screw to the blade and chipbreaker together, the middle will go down in a curve and thereby forcing the ends up, creating a small gap near the cutting edge. It rests on the "inner" side of the surface. You will need to change the angle by flattening it with the top end lower than the stone. Then it will rest on the front of the surface closest to the cutting edge.

Does it make any sence what I'm writting. English is not my first language, so it can be a little difficult to explain technical things. Anyway i hope it helps to your troubleshooting.

Besides that, I agree with Clinton on flatness. There's scientific flatness and there's practical flatness. I have a 10 mm glass plate and some granite bathroom tiles, and that is more than good enough in my opinion. If you can't distribute even pressure with your fingers throughout the whole flattening process, science is not gonna help you anyway. But that's just my opinion.

Thomas

Ok, yes, nice and clean, maybe polished (but maybe not) meeting point at the very tip at an acute angle will do. Both the Record and Hock are as sharp as the steel can support, or close enough to it.

Difference with the Record and Hock is that the Hock is nicely ground on both sides, the Record is as rough as guts. Not even flat on the bevel side, but it still delivers the goods with enough tension on the cap iron and lever cap...

If the iron is being worked in the middle, but not the sides, it's bowed and that's a real problem. Still, I'd make the back bevel large enough to make sure it's the full width of the blade, then do the bevel side so you have an edge the full width. Back the cap iron away from the edge, maybe 2mm or so, and keep it right out of the way and use the iron for rough work, because it's not going to be worth snot until you can get that cap iron to close up all the way across.

And I'd be looking at a new iron. Luckily, these are not too expensive. Well, at least they won't be when I get around to putting some up for you unwashed masses. Looking at about $42-45 shipped for your #4, blue steel laminated to plain steel, 2.2mm thick. Not yet though, still need to run a few through the wringer before I start offering them and I won't do that until I know what I'm sending out, first hand. They'll be good, but just how good I need to know. Anyway...

If you're heck bent on getting that blade flat, find out at which point the back is actually flat. No need to be perfect, just how far back from the edge is the off corner. Grind the iron back to that point, and get it working again. The steel you grind away is not being lost, since as it is, the blade is a pain in the backside and getting rid of the problematic steel will save trouble in the long run and it's worth it to just blow it all away. Seriously.

However, if you need a stone to work that over then I'd recommend either a diamond plate of some kind, coarse to start with. No finer than #400 and make sure it's flat. Wet down the plate, add a drop of dishwashing liquid, and gently rub back and forth. Keep at it, periodically cleaning off the swarf and replenishing the water and drop of soap, until it's as flat as you need the blade to be.

If you need stones, then yes it can be done, but it's not going to be easy or inexpensive and I'd have trouble suggesting spending the money for a blade that sounds like it's better off being replaced. It's a #4, and blades are available. If it was a unique iron, then maybe it's worth the effort.

(John M, you were right! Ha ha!)

I'm not rich, and right now I'm kinda stretched thin for anything for myself. I've got some stones ranging from the useless to what can only be described as brutal in their hatred for hard steel, and I wouldn't waste my time flattening, I'd save my lunch money for a new blade.

Right now, I've got a sintered diamond plate on the sink, and it's not real fast but the thing will NOT dish. Loads up a little, but not a show stopper. It just keeps going and going, and the nice part is the 22mm ally backing plate and the fact that you can push on it as hard as you want, it doesn't care. Do the same with an electrocoated diamond plate, and it's in the bin before you're 5 minutes in. I've got fast stones, hard stones and hard and fast stones. I've got stones that will chew up and spit out any steel you've ever heard of, and even with all that just sitting there, I still wouldn't put too much effort in a blade that's not worth it.

However, since Clinton asked nicely (and he's big enough to hammer me into the ground if I don't comply!) I'm actually using a Sigma Power ceramic #1000 (hard), followed by a Sigma Power ceramic #6000. After that I use the Sigma Power #13000, but that one's a luxury (even if it's a nice stone). The #1000 is hard enough, fast enough and will not stop no matter what you do to it. It's what the Shapton Pro #1000 would be like if it wasn't hobbled by not needing a soak, and was a little finer in grit, and had harder abrasive in it.

Where most folks see soaking as trouble, the simple fact is that not soaking actually compromises how well these medium grit stones can cope with being worked hard. I'd like to go into details, but I'm running out of room here I think. Simply put, for a #1000 grit stone, soaking is a benefit not a hindrance.

Just for comparison, the Shapton Pro stays a little flatter then the Sigma (but not by enough to actually notice, and I only know by extrapolating collected data), The Sigma cuts just as quickly but the Shapton will not last as long as the Sigma and is more expensive as well. The Shapton is also quite fragile where the Sigma is nearly indestructible.

The Sigma #6000 is good enough for most planing and for chisels all by itself. The edge can be improved of course, but what it gives you is enough to pop hairs, pare end grain, etc, etc. The edge is good, and honestly has no equal at this grit level. The Chosera #5000 is nicer to use than the Sigma, and is quicker but leaves a finish that's not anywhere near as good as the Sigma. I like the Chosera as a user, but I'd be a fool to select it as my only #4-6000 stone.

I could use diamond plates of course, but they are a little fragile and I usually reserve them for just using on stones. I've used them with steel in the past though, and will probably do so again in the future, but I've got so many stones that I suppose I better use up some of them first.

Stu.

Originally Posted by Schtoo

And I'd be looking at a new iron. Luckily, these are not too expensive. Well, at least they won't be when I get around to putting some up for you unwashed masses. Looking at about $42-45 shipped for your #4, blue steel laminated to plain steel, 2.2mm thick. Not yet though, still need to run a few through the wringer before I start offering them and I won't do that until I know what I'm sending out, first hand. They'll be good, but just how good I need to know. Anyway...

This sounds interesting - I shall definitely be keeping an eye out for those!

Thanks Schtoo for your reply, I've contacted you through your website.

(and thanks Tiger, for your patience with my 'kinda' hijack)

oh,

Clinton asked nicely (and he's big enough to hammer me into the ground if I don't comply!)

... I feel compelled to explain that to the www community, but you've stumped me. ... but I'm a good bloke! honest!

Folks, yes Clint is a very nice fella, but if I recall right, he's about a foot taller than I am.

Over here where I am 'oversized', anyone bigger than myself sticks in my memory...

Got the email too, thanks.


NZStu, I don't know when they'll be up. I don't have one of my own yet (forgot to grab a few last time I was in Miki) but as soon as I do and make some token attempts to get them sharp and flat backed, I'll be putting them up for sale. Probably offer to get them ready to go for a token fee as well, just to take that potential minefield out of the equation. They're already surface ground so they are flat, but I think polished and very sharp might be a nice bonus for some.

I'm just not sure how to ship a chunk of razor blade without it losing it's edge or losing one of the postman's fingers during the trip...

Another Stu.

Originally Posted by Schtoo

NZStu, I don't know when they'll be up. I don't have one of my own yet (forgot to grab a few last time I was in Miki) but as soon as I do and make some token attempts to get them sharp and flat backed, I'll be putting them up for sale.

Another Stu.

I'm in no rush - just planning on upgrading the blade on my jointer sometime in the future when funds and priorities allow it...

(loving the chisels btw )

Schtoo you make some good points, I could just grind back to the flat stuff. But why take the easy way out when you can make things more difficult . I bought a DMT Diamond stone Coarse grade. Put the plane iron on and at first it seemed to cut but after 20 mins or so it didn't seem to do anything, checked the iron, it's a little better (I would have got extra coarse diamond stone but they didn't have any stock).

I then got out my float glass, the coarsest grit I hand on hand which was 100 and kept trying. Now I one edge is fine, the other edge is much better, now there's only about 4 mm left to do. Probably good enough for now. I had thought that the diamond stone was going to make quick work of it, it gave me a nice polish but that's all.

Originally Posted by Schtoo

I'm just not sure how to ship a chunk of razor blade without it losing it's edge or losing one of the postman's fingers during the trip...

Dip the cutting edge into a hard, molten wax of sorts. Our countersinking bits we get are usually protected this way so it must be available somewhere.

Originally Posted by Tiger

Schtoo you make some good points, I could just grind back to the flat stuff. But why take the easy way out when you can make things more difficult .

I then got out my float glass, the coarsest grit I hand on hand which was 100 and kept trying. Now I one edge is fine, the other edge is much better, now there's only about 4 mm left to do. Probably good enough for now. .

Hi Tiger,

I'd grind back to the point where the dubbing of the edge is gone as Stu said.

More importantly, the problem you are trying to solve is to stop the chips jamming between the backing iron (aka chipbreaker) and the plane iron.

Use a file or hammer to get the chipbreaker to match the profile of the plane iron. Hold chipbreaker in position and adjust until there's no daylight left in the gap between the two.

This is what the gentleman from Denmark was alluding to.

Reassemble plane

Problem solved (I hope.)

Cheers,

eddie

Thanks, Eddie, as it turns out I'm still having problems with the chipbreaker but it has improved. Will try the file.