# Hand Plane Blades: How straight is straight enough?



## KentInOttawa (Jun 25, 2013)

I was recently using my old Stanley #5 for the first time. I had already done some lapping and fettering to get it working better, but I didn't go overboard for fear of hurting its value. Since then, I've been reading a lot more about planes, and I realise that this plane has much more value as a user than as a collectable. Good, that's what I want.

Anyways, the mouth of this plane started jamming with very fine chips. My investigation showed that the Sweetheart iron that was installed in this plane (a type 16?) was quite bent and twisted. I swapped out the iron and the plane started to work well without clogging.

By using my metal bench vise as a press, I was able to get most of the really bad bends and twists out, but this iron still isn't "perfectly flat". Okay, it's not even close. I checked it on my granite block after straightening and I can still slip a .015" (!) feeler gauge between the iron and the granite. I checked out the flatness of both my granite block and my flattest anvil. The granite was flatter than I can measure, but the anvil was at least .020" out of flat.

So how do I straighten this blade, and how straight is straight enough? Do I also need to flatten my anvil?


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## OSU55 (Dec 14, 2012)

Not sure how to flatten the blade. The chips jamming in the mouth was probably due to chips getting under the chip breaker. The chip breaker has to mate flat with the blade - no gaps. The blade is probably scrap.


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## Ocelot (Mar 6, 2011)

The entire blade does not have to be flat, only the first 1/4" or so where the chipbreaker meets it. That much can be flattened on your surface plate with sandpaper or on a diamond plate.

-Paul


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## KentInOttawa (Jun 25, 2013)

OSU55 and Paul, you're entirely correct about where the chips are getting stuck. The iron has already been flattened for the first 1/4", but the chip breaker still does not fit tightly against the blade because the entire blade is bent and twisted that badly. The chip breaker is working fine with the replacement blade; it just isn't strong and heavy enough to pull enough of the twist out of the blade to make it fit tightly.

I have made the situation better with the judicious use of force on the twisted blade; I just haven't been able to get enough of the twist out of it for the chip breaker to fit correctly.


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## TheFridge (May 1, 2014)

I sometimes use a 1/2" dowel hit with hammer to help straighten spots of an iron.


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## jdmaher (May 4, 2011)

If it's just a user, why not just buy a replacement blade?


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## Ripthorn (Mar 24, 2010)

I would just toss the blade. An inexpensive replacement from HD can be had for $3-5 and those work relatively well. I have one in my #4 and it takes whispy thin shavings.


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## donwilwol (May 16, 2011)

Some pictures would help. Are you sure it's not a problem with the chip breaker?


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## rwe2156 (May 7, 2014)

The only way to flatten hardened steel is heat it to kill the temper. Then retemper if you've managed to get it flat.
If you can flatten a plane blade without doing that I would question the quality of the steel.

I would get a new blade. I recommend Hock or Veritas. I wouldn't buy a used one.


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## OSU55 (Dec 14, 2012)

Try this link http://www.stanleytoolparts.com/beplcu.html. 2" double iron for $3.50. It's best to buy several if you can use them to spread the shipping cost.


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## KentInOttawa (Jun 25, 2013)

Don,

When the chips are jamming in the breaker, they only ever jam on the right side (when viewed from the flat/breaker side of the iron). I did the sharpee trick and tried reflattening the blade quickly this morning using 120 grit sandpaper on granite and a course diamond plate (220?). Neither wanted to take the surface down quickly, but they revealed a definate hump just about 3/16" back from the cutting edge.









Just before this flattening, I checked the clearance (gaps) in the breaker, and I got about .004" on both sides. This does not make sense to me; equal gaps but clogging only on one side?

The chips breaker fits well on another blade, with less than .0015" gap, my thinnest feeler gauge. Nice shavings can be made with that other blade.

TheFridge,

Where exactly would I be hitting this blade? I'm guess somewhat centred on the high spot in the above photo?

-------

Forgive me if I seem to be missing something obvious here, but just investigating this, doing that small amount of flattening, trying to get a good photo, and then writing up this entry have stressed both my brain and my vision to their limit for the day. I will need to let them recover for a day or two before I can get back in the shop to do any more.


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## Ripthorn (Mar 24, 2010)

> The only way to flatten hardened steel is heat it to kill the temper. Then retemper if you ve managed to get it flat.
> If you can flatten a plane blade without doing that I would question the quality of the steel.
> 
> I would get a new blade. I recommend Hock or Veritas. I wouldn t buy a used one.
> ...


This is not entirely true. Think of how hand saw blades can be hand tensioned by hammering them. Even though the steel is hard, it still has some give. Hitting it in the right spots will create internal tensions that can straighten it out to a degree. A hand plane iron is usually at about 60-62 HRC, which still has some give to it, regardless of the quality of the steel.


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## RichardHillius (Oct 19, 2013)

How flat does a plane iron need to be? If it's not flat it won't seat against the frog securely and when you push it into a piece of wood it will flex and chatter. I have run into a few twisted irons in my time and I just swapped them out for ones that where already flat. Spare irons shouldn't be that hard to find be it antiques or new replacement brands. It also has to be flat enough that there are no gaps between the chip breaker and the iron or you will get shavings wedged between the two.


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## bandit571 (Jan 20, 2011)

Depends on which way the "bends" go.

Might see what happens when the chipbreaker is attached to the iron.

Might also check the chipbreaker for flatness, as well. Have had to tap more than a few cb's back into flat. I check then by laying them flat on a flat surface. First one face, then the other. I try to rock the cb to test where it may be bent at. Sometimes, they are bent right in the middle with the curved side up. I will then flip it over, use a punch and the hammer, and a few whacks right into the highest spot. Flip it back over, and recheck. Some take a few tries, some don't. THEN I can mate the cb to the iron. I look to get a knife edge where the chipbreaker will sit on the iron. That way, when the two are tightened together, the edge will deform just enough to seal any small gaps. I also polish the curved part of the chipbreaker so chips have a smooth path up and away.

Do NOT place the iron in the vise and then use your hands to "pull it back into straight…..irons will snap
DAMHIKT…..


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## KentInOttawa (Jun 25, 2013)

*Bandit*

Thanks for the reply. I can rock both the iron and the blade on my flat surface (granite), and I can measure the height of the corner that doesn't touch it at rest. I've even managed to take some of the really bad bends out of the blade using the techniques that you describe. I did use the vise for that, too, although only as a sort of a press; it helped with one gnarly ~5 degree bend in the tail of the iron.

Here's what's stopping me from continuing to straighten the blade now:

I don't want to use the granite as an anvil
the top of my flattest anvil is about .030" out of flat
my eyes (vision) are really very, very bad right now; I'm recovering from a very serious contusion. The iron is about .020" out of flat at the one corner and possibly more in the middle, but I just cannot see (or feel) where the bends and high spots are. I can see light between the blade and a straight edge, but my resolution is so low that I can't see where the two touch. When I know where to hit (see the picture above), I can get the blade straight enough (see below).








as mentioned, I can measure the gaps at the corners with a feeler gauge. When I put the iron and the chip breaker together, the gap between them is BIGGER than the sum of the gaps. "Does not compute".

How can I straighten it when I don't know where to hit? Are there any other techniques (like a hydraulic press) that I could use?

*OSU55*

Thanks for the link. I have some other irons and am currently using 1 pair in the #5, but because that looked to me to be an awesome price, I went to check the link out. That site should be a case study about failed customer service. Here's why:

they were out of stock of everything I tried to find (blades, caps and irons for #4 & #5 planes)
they refered me to SERVICE NET, where they had the parts. But Service Net's FAQs say that they won't ship them to me; I'm Canadian, eh!
The Service Net FAQs then send me to 2helpU so that I can find my local Stanley service centre.
2helpU will only let you select your country by tunnelling down through the appropriate continent, then selecting your country. Apparently, Canada isn't in North America! In fact, according to 2helpU, it isn't on any continent.
There is no way to contact 2helpU

*Stanley, are you listening?* It's faster and easier for me to physically get to Lee Valley from here (6 miles away) than to find your service centre online (right in front of me).


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## Ripthorn (Mar 24, 2010)

If you have a machinist style bench vise, you can put in a small piece of round rod or similar at the crown of the bend and then begin to slowly tighten. Once it looks like you have over travelled a little bit, loosen and check, as it will spring back some.


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## Ripthorn (Mar 24, 2010)

As a side note, if I had a Lee Valley 6 miles away, I would have precisely zero dollars in my bank account…


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## donwilwol (May 16, 2011)

> As a side note, if I had a Lee Valley 6 miles away, I would have precisely zero dollars in my bank account…
> 
> - Ripthorn


Ain't that the truth!!


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## KentInOttawa (Jun 25, 2013)

> As a side note, if I had a Lee Valley 6 miles away, I would have precisely zero dollars in my bank account…
> 
> - Ripthorn
> 
> ...


The only reason that Lee Valley's stock hasn't exploded is that I can buy good tools on the used market too easily, so I spend my money before I've accumulated enough for the good LV stuff. The result is more or less the same for me though; my bank account IS empty.

My plane collection increased by about 50% this week. I received a Record 045C and a 778, as well as a Stanley 71. The Records came from 2 different sellers. Both these planes look like the original owners bought these planes, dropped the blades in and tried them out, without ever sharpening them. I suspect the somewhat predictable results caused the planes to be packed away (one in the original box) until they were eventually sold.









I can't wait to get these tuned and taken for a whirl.

I took Ripthorn's recommendation and adapted it a bit. I've used a straight edge to find a high point on the blade, and then placed the blade in a vise with a round pin clamped against the high point. I also shimmed the other side of both ends to allow the blade to flex a bit more. The shims were just something that was convenient and flat. As a bonus, they came with handles ;-) I did not clamp it very tightly; just enough to get some pressure.









It looks kind of scary. I'll check the blade in a day or so to see if I applied enough (or too much) clamping pressure.


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## bandit571 (Jan 20, 2011)

Oh, you will know instantly IF you apply too much..









I had to have this welded back together…..Ohio Tool Co. No.0-7…..the one with the Globe logo on the blade…

Took a bit of tune up after, blade works fine, now.


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## KentInOttawa (Jun 25, 2013)

I can see how that could really get your attention :-D

I also found out why I was having such a hard time figuring out my blade. I continued to clamp and straighten the blade using variations like above. Then I started to notice up to .020" differences from one edge to another, and the blade was bent along its length. Imagine a board with TWO bows (low spots) on the face! So I gave a quick 120 grit flattening and used sharpees to show high and low spots. Here's some pics of the results (I've "highlighted" the shiny [high] spots with black sharpee so that it is easier for *me* to visually process):


















Think about the high (black) spots shown in the photos, especially along the keyhole. Using my board analogy, this is like having a slot down the middle of the board with similar twists on each side, which means that the high side of one twist is beside the low side of the other. That means that the keyhole has a more severe twist than the blade. Damn! I'm having difficulty straightening out a blade and now I find out that I need to straighten out the hole. Dr Gumby, my brain hurts!

Follow this: When checking the entire blade, I could slip a .020" gauge under the edges, *but* I only checked the gap of the one face. After seeing these high spots, a decided the check the gaps on either side of the keyhole separately: .015 & .018". That's a difference of .033" across the width of the 1/2" keyhole. It's ever so obvious now why the chip breaker was twisting so badly.

It's going to take a few days for me to straighten this blade, but, thanks to the folks who've responded, I've been able to work through my injuries and flatten the blade enough to understand what is wrong with it. I also have a couple of effective ways of correcting the blade. I'll post some pictures of the flat blade within the week.


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## rwe2156 (May 7, 2014)

Buy another blade its not even worth the time its taken you to post the narrative.

.....just sayin'


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## KentInOttawa (Jun 25, 2013)

> Buy another blade its not even worth the time its taken you to post the narrative.
> 
> .....just sayin
> 
> - rwe2156


If it was just about getting the chip breaker to fit the blade, or for the #5 to stop clogging, you'd be right. But I was trying to "think through" how to repair a twisted blade with *a LOT of things working against me*. Two years ago, I was run down by driver that did not correctly perceive that there was a pedestrian in the intersection he was turning into. Among other things, I received a Traumatic Brain Injury (TBI) for that failure.

It has taken a lot of time and work, but the vision therapy that I'm doing has allowed me to start some relatively simple tasks in the shop.

This posting, as long-winded as it is, is helping me to recover from my TBI by reinforcing my vision therapy. Working in the shop does the same thing. Just a few months ago I would have had trouble figuring out how to assemble 2 boards precut with a through mortise. Yes, it was that bad. Today, with the help I've received on this thread, I've been able to determine how the twists and bends caused that gap between the blade and the chip breaker. The neuronal connections that have been re-established will continue to help me as my long recovery progresses.

Many thanks to those that helped me get over this particular bump in my path.

So, for me, it has been worth the effort.

.....just sayin


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