How to Fix Bowed Plane Blade
#11
  
Before I take my trusty Harbor Freight (HF) rubber mallet and beat the crap out of my Stanley 2-3/8 iron, I thought I would check here; beat it, or do something a little more scientific?

Right now the iron bows away from the chip breaker, probably a 1/16th inch in a span of just under 8-inches free and un-cinched.  Most of the breaker and iron contact leaks light. It was collecting sawdust and occasional shavings. The two are in pretty decent shape otherwise. I am hoping a decent clamp action, once the bow is fixed, will close the breaker contact.

I'm not a metal or machinist person so was hoping for some guidance.  Your thoughts are appreciated. Thanks,
Bruce
Bruce
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#12
  Re: How to Fix Bowed Plane Blade by hbmcc (Before I take my tru...)
I Have used a ball pean hammer to correct some bowed irons, before.   Just lay it bow up on the bench.    Bad bows.....I may add a shim at one end....


There is a non-hammered way.....involves a wood vise, and three dowels.   Middle dowel is on the top of the bow.   Vise closes down,, pushing the single dowel into the bow.   the other two dowels are on the other side of the iron.one at each end.    You may have to go a little past straight, to allow for springback.


Do NOT clamp the iron into a vise, and try to simply bend the bow out....iron WILL snap/break.....I got lucky, and didn't get any  cuts from it.  

One  could install the chipbreaker on the "wrong" face of the iron ( bevel side) and let it sit a while.....have rehabbed quite a few planes where they had installed the iron "bass-ackwards"   causing a bow.   Flipped the iron over, installed the chipbreaker...no bow.
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#13
  Re: How to Fix Bowed Plane Blade by hbmcc (Before I take my tru...)
Hammer blows will correct that, its sort of hard to screw that up, but an anvil helps. Just take it easy and don't overdo it. If I didn't have an anvil, I like Bandit's dowel/vice technique, especially for one that is really buggered up. But yours ain't that bad, a few blows will do it for you.
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Non impediti ratione cogitationis
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#14
  Re: RE: How to Fix Bowed Plane Blade by bandit571 (I Have used a ball p...)
(10-11-2018, 12:40 AM)bandit571 Wrote: I Have used a ball pean hammer to correct some bowed irons, before.   Just lay it bow up on the bench.    Bad bows.....I may add a shim at one end....


There is a non-hammered way.....involves a wood vise, and three dowels.   Middle dowel is on the top of the bow.   Vise closes down,, pushing the single dowel into the bow.   the other two dowels are on the other side of the iron.one at each end.    You may have to go a little past straight, to allow for springback.


Do NOT clamp the iron into a vise, and try to simply bend the bow out....iron WILL snap/break.....I got lucky, and didn't get any  cuts from it.  

One  could install the chipbreaker on the "wrong" face of the iron ( bevel side) and let it sit a while.....have rehabbed quite a few planes where they had installed the iron "bass-ackwards"   causing a bow.   Flipped the iron over, installed the chipbreaker...no bow.

This method works.  It's a bit easier if the dowels on the opposite side of the bow are flat strips instead of dowels.  Sometimes it's hard to keep the dowels from rolling while clamping.  Also, the blade is steel, not iron.  Most iron will, indeed snap (brittle fracture) unless it's ductile iron (like modern hand planes).  Most vintage planes have steel blades.  Unless yours is laminated, I think you'll be OK using Bandit's method.
Still Learning,

Allan Hill
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#15
  Re: How to Fix Bowed Plane Blade by hbmcc (Before I take my tru...)
Thanks gentlemen! That works for me. 

I wonder, if based on your advice, could the chip breaker and lever cap be causing the blade to bend permanently? Maybe, there is an upper limit to what is safe for clamping compression? (It's easier to know one of the limits, at lever cap, in modern planes--no adjustment.) I intend to work the contact edge of the breaker. I think clamping harder than desired to remove gaps may have exacerbated the blade deflection.
Bruce
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#16
  Re: RE: How to Fix Bowed Plane Blade by hbmcc (Thanks gentlemen! Th...)
(10-11-2018, 10:53 AM)hbmcc Wrote: Thanks gentlemen! That works for me. 

I wonder, if based on your advice, could the chip breaker and lever cap be causing the blade to bend permanently? Maybe, there is an upper limit to what is safe for clamping compression? (It's easier to know one of the limits, at lever cap, in modern planes--no adjustment.) I intend to work the contact edge of the breaker. I think clamping harder than desired to remove gaps may have exacerbated the blade deflection.

I doubt the chipbreaker would cause that.  As far as the lever cap, possible.  Adjustment of the lever cap pressure is somewhat more of an art than science, in my experience you need a clean "click" from the lever cap lever, too much pressure and the iron won't adjust properly, too little and it can move a bit.  You don't want to have to force the lever into place, but you want it firmly in place.  That's the best I can explain it.
Elvem ipsum etiam vivere
Non impediti ratione cogitationis
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#17
  Re: How to Fix Bowed Plane Blade by hbmcc (Before I take my tru...)
(10-10-2018, 11:23 PM)hbmcc Wrote: Before I take my trusty Harbor Freight (HF) rubber mallet and beat the crap out of my Stanley 2-3/8 iron, I thought I would check here; beat it, or do something a little more scientific?

Right now the iron bows away from the chip breaker, probably a 1/16th inch in a span of just under 8-inches free and un-cinched.  Most of the breaker and iron contact leaks light. It was collecting sawdust and occasional shavings. The two are in pretty decent shape otherwise. I am hoping a decent clamp action, once the bow is fixed, will close the breaker contact.

I'm not a metal or machinist person so was hoping for some guidance.  Your thoughts are appreciated. Thanks,
Bruce

I think I'd replace it.  Those irons are plentiful enough.  They are pretty hard for much of the blade.  I think if you try to bend it, it will be harder to do than maybe we think and not worth the trouble.
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#18
  Re: RE: How to Fix Bowed Plane Blade by adamcherubini ([quote='hbmcc' pid='...)
(10-12-2018, 11:11 AM)adamcherubini Wrote: I think I'd replace it.  Those irons are plentiful enough.  They are pretty hard for much of the blade.  I think if you try to bend it, it will be harder to do than maybe we think and not worth the trouble.

Yikes!!  What can it be replaced with? I think Veritas was about $70 for new chipbreaker and blade copy. Hock is about $50. However, going on casual two or three week memory for these numbers; and, a new chipbreaker is a given. A hammer would be a better intermediate step. 

There is a paucity of hand tools where I live, and flee markets are worse than real estate at pricing.
Bruce
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#19
  Re: RE: How to Fix Bowed Plane Blade by hbmcc ([quote='adamcherubin...)
(10-12-2018, 07:53 PM)hbmcc Wrote: Yikes!!  What can it be replaced with? I think Veritas was about $70 for new chipbreaker and blade copy. Hock is about $50. However, going on casual two or three week memory for these numbers; and, a new chipbreaker is a given. A hammer would be a better intermediate step. 

There is a paucity of hand tools where I live, and flee markets are worse than real estate at pricing.
..............................
Seems like you have nothing to lose by attempting to correct the problem yourself...I would not use a rubber mallet tho..too much "rebound"...Instead use a brass or steel hammer or better yet a "dead blow" or lead hammer which you probably don't have..Place the cutting end on a 1/4" dowel and strike the blade smartly in the are of the bend then check to see the progress...repeat as required, check it frequently. .It's quite possible you can save it. Good luck....
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#20
  Re: How to Fix Bowed Plane Blade by hbmcc (Before I take my tru...)
(10-10-2018, 11:23 PM)hbmcc Wrote: Before I take my trusty Harbor Freight (HF) rubber mallet and beat the crap out of my Stanley 2-3/8 iron, I thought I would check here; beat it, or do something a little more scientific?

Right now the iron bows away from the chip breaker, probably a 1/16th inch in a span of just under 8-inches free and un-cinched.  Most of the breaker and iron contact leaks light. It was collecting sawdust and occasional shavings. The two are in pretty decent shape otherwise. I am hoping a decent clamp action, once the bow is fixed, will close the breaker contact.

I'm not a metal or machinist person so was hoping for some guidance.  Your thoughts are appreciated. Thanks,
Bruce
If I read the description correctly, the bow is in the lengthwise direction. This would have nothing at all to do with the cap iron gap. The cap iron gap must be corrected independantly.

The bow in the lengthwise direction "bows away from the chipbreaker (cap iron)" Generally tightening the cap iron screw will pull the iron toward the cap iron. This may completely eliminate the problem. Even if the bow does not completely flatten out, tightening the lever cap ought to eliminate this problem.

I would first fix the cap iron gap so the shavings cannot get through and then see if there are additional problems that can be traced to the bowing.
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