Sunday, March 11, 2018

Stanley #4 1/2 Problem

Lately I've had a problem with my Stanley #4 1/2 smoother.  This plane has become my most used plane.  Not long after I got it, I broke the iron trying to remove a belly on the back side and so I bought a Hock iron and breaker.  At the time I flattened the back and all was good.  But lately I've been having a problem with shavings jamming in between the breaker and iron.
Shavings jamming up the works
You can see a HUGE gap between the iron and breaker on the right side.  It's not normally that large; the shavings pry it open more than it normally is.
Here's an end-on view - look at that gap at right!
So I removed the shavings and investigated.  With the iron and breaker reassembled I held it up the the light and could see a gap at both ends.  It's nearly impossible to get a good picture of this.

The chip breaker looked fine.  At some point I had flattened the mating edge for just this reason.
The Hock chip breaker
You can see the leading edge has been flattened
I flattened the back of the iron after I bought it.  You can see the shiny inch or so at left in the next pic.
Back of the Hock iron
Well, something changed.  While I once had a nice flat back and a chip breaker that mated nicely, now I have crap.  A week or two ago I spent the better part of a day trying to flatten the back of the iron again.  I was getting nowhere and bagged it for then.

But the time came again because I really rely on this plane.  So today (Wednesday) I worked on it again.  I spent a couple of hours working the back on a coarse diamond stone.  It's a fair bit better, but I could not get to the outside edges.
Low spot in center, low areas at sides
I hated to do it, but I gave in to temptation and put a back bevel on the iron.  I would much rather have gotten the back flat the right way, but even a coarse diamond stone was not getting it done.  I think it's flat enough that shavings will not get jammed up, but time will tell.

I made the back bevel very small - about a millimeter - so if I want to get rid of it later I can grind it off.  This was a very frustrating exercise for sure!  Now let's see how the plane behaves.

EDIT: after using the plane a bit, I still have shavings jamming in between iron and breaker.  Arrrgh!  Sometime soon I'll work it with some coarse sandpaper to lower the middle 90% or the back.  Then I'll put it back on the diamond stones.  If that doesn't fix the problem, I may find a new iron.  Frustrating!

11 comments:

  1. There should be a secondary bevel on your cap iron in addition to the primary. This secondary bevel should be relatively blunt, ~50deg. It makes a big difference as to how the chip is directed up and out.
    https://vimeo.com/158558759

    You really only need to flatten the first 1/8" or so of the back of the blade. Your working too hard to flatten that much steel at once.

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    1. Thanks, Greg. I've seen that video a few times. I've seen someone else espousing the idea of a steeper front upper edge to the breaker too. I might try that. However, getting the breaker to about 0.2 mm from the iron's edge is a stretch. That's about 0.008" or 1/128", which is tough to see. But my first priority is getting the iron flat and the bottom of the breaker to mate perfectly with it. An eighth of an inch would be tough to hold steady though - I need more surface to reference on the stone. Maybe I'll try 1/2"

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  2. I think I'd call Hock and maybe they will help you out or replace it. You shouldn't be having to tune an expensive iron and chipbreaker every time you use it.
    Steve

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    1. Steve, I didn't mean to imply there was something wrong with the Hock iron. It performed very well for the first couple years I'd used it. But something has changed to get it out of flat. I suspect it was something I've done.
      It could have something to do with the stropping I was doing - maybe it was relieving the sides of the back more than the middle. But that seems like it would take millions of strop strokes to make that much of a difference. Maybe I'm not getting the leading edge of the breaker truly flat. It's something that's hard to verify other than by mating it with the iron. I'll keep working on it to figure it out - I really need that plane!

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  3. Matt, try setting the chipbreaker a bit further back from the iron. See if that does anything to improve the jamming.

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    1. Thanks Ralph. I'll try that, but my low spots at the sides of the iron's back extend about a half inch from thee edge.
      Also, I've read/learned that keeping it close up to the edge is the way to go to avoid tear-out. Thanks for the suggestion.

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  4. Chris Schwarz has a blog entry on tuning up the chip breaker. It involves flatting the mating surface of the chipbreaker and then rolling the edge of that mating surface with a burnisher to create a surface that is more likely to have no gap. Ive tried it, it works great.

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  5. Follow-up --I found the blog on popular woodworking --
    Search -- Fine tune a Handplane’s Back Iron
    By: Christopher Schwarz April 28, 2015

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    1. Wow, thanks a lot TMP. That's really interesting about turning a burr on the breaker. I've got some things to try now.

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  6. I once had a plane iron from someone else where the iron and cap iron had reverse convex warps. There was a noticeable gap when the assembly was out of the plane. I returned them as it was clearly a manufacturing defect.

    My 2 cents on the back bevel is that it can only make your situation worse.

    If you run your lever cap on the loose side, you may want to tighten it up a small amount. Unless you have a burr or something on the cap there has to be enough pressure on the cap to keep shavings from forcing their way in. Some planes have a loose enough fit on the lever cap screw that it can turn when you have everything out and not go back where it was. That could explain the sudden onset of your problem.

    Steve

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    1. Thanks for the comment, Steve. My problem wasn't with the lever cap, but with the chip breaker. My shavings are jamming under the breaker, which is set about a 64th to a 32nd from the edge of the iron.

      I could see the lever cap being an issue, however, as the pressure it applies on the chip breaker should help the breaker to seat against the iron. But the lever cap screw hasn't changed position, so I don't know if that's the issue.

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