Have I completely messed-up the cap-iron of my plane?

[baldpate]

Hi,

I've got a Stanley No. 4 which I bought new about 20/30 years ago (not sure exactly), but which never performed very well. It had been consigned to gather dust on a shelf for the past few years (I've acquired a couple of nice Record planes, and learned to sharpen & adjust them).

I recently 'rediscovered' the Stanley and had a look to see if it could be tuned-up. One thing that was obviously wrong (apart from the fact that the cutter was pretty blunt!) was that both irons were not square. After squaring & sharpening the cutter, I had a go at squaring the front edge the cap iron. I was obviously too heavy-handed, because now the cap iron only just clamps onto the front of the cutter when the cap-iron screw is fully screwed down (i.e the irons only just lightly clamp together).

My questions:

1. Was I wrong to bother with squaring the cap iron? Reading around on the subject, it seems that the function of the cap iron is to make (in effect) a thicker, more stable, cutter: is that right? If so, I wonder now if it mattered that the front edge of the cap iron was out of square with front of the cutter (were talking about 1mm over 2 inches). Perhaps I should have left it alone.

2. Can I now correct the problem? Perhaps by putting a thin shim between the cap and cutter at the top end of the cap iron? Or maybe I should just buy a new cap iron !

There's a lot of stuff on Google about sharpening cutters, but nothing I can find about cap irons.

Anything you can tell me will be gratefully received - Thanks.

Chris

 

[Recky33]

You could always bend it a bit more on the curved bit in a vice, that will put some tension back in it

 

[matthewwh]

If it's the old thin type with a big curve then I'd go for the 'maybe' option. There's fettling, and then theres the moment of quiet inner acceptance when you realise that you can't polish a tu*d.

Cap irons are the single biggest problem with bench planes and changing them is probably the cheapest and most significant improvement you can make.

I fitted a QS 1-3/4 to my Record compass plane and the change was like night and day - amazing.

 

[Jacob]

..... the cap iron only just clamps onto the front of the cutter when the cap-iron screw is fully screwed down (i.e the irons only just lightly clamp together).....

You could bend it a bit - stick it in a vice and give it whack. But it doesn't matter that much anyway, as much more important is the pressure of the lever cap on to the cap iron thereby pinning the blade down tight to the frog.
Even more important is whether or not it planes OK, so I'd check that first - you might need to fettle a bit. :roll:

Cap irons seem to be the single biggest problem with bench planes and few minutes fettling them will be the cheapest and may be the most significant improvement you can make. :lol:

 

[Paul Chapman]

much more important is the pressure of the lever cap on to the cap iron thereby pinning the blade down tight to the frog.

I do wish you'd stop advising people to use the pressure of the lever cap to force the blade into contact with the frog, as you've done several times lately. If you need to use a lot of force on the lever cap then it indicates other problems with the plane.

Cheers :wink:

Paul

 

[Jacob]

... If you need to use a lot of force on the lever cap then it indicates other problems with the plane.

Cheers :wink:

Paul

If you don't use enough force then you will have problems. Within reason of course - just firmly clipped down.
I keep going on about it because others keep going on about problems with cap irons, which in my view are easy to fix.
3 or 4 people have raised the issue recently. I didn't know people found them so problematic.

 

[bugbear]

One thing that was obviously wrong (apart from the fact that the cutter was pretty blunt!) was that both irons were not square. After squaring & sharpening the cutter, I had a go at squaring the front edge the cap iron. I was obviously too heavy-handed, because now the cap iron only just clamps onto the front of the cutter when the cap-iron screw is fully screwed down (i.e the irons only just lightly clamp together).

My questions:

1. Was I wrong to bother with squaring the cap iron? Reading around on the subject, it seems that the function of the cap iron is to make (in effect) a thicker, more stable, cutter: is that right? If so, I wonder now if it mattered that the front edge of the cap iron was out of square with front of the cutter (were talking about 1mm over 2 inches). Perhaps I should have left it alone.

2. Can I now correct the problem? Perhaps by putting a thin shim between the cap and cutter at the top end of the cap iron? Or maybe I should just buy a new cap iron !

In a plane with a lateral adjuster, getting the blade dead square is not super important. If it's only a little out, the plane will work fine, and the blade can bought square gradually (by just emphasising your sharpening pressure) over the course of normal sharpening.

It is a little more important that the cap iron edge be parallel with the blade edge, since the cap iron is the thing that ultimate fixes the blade (and hence the cutting edge) in place.

I assume you've either filed or ground the cap iron, quite a bit.

If you're really removed a significant amount of the curved portion of the cap iron, I think it's (effectively) a goner, and I would trawl boot fairs (or this forum) for a replacement. Cap iron don't normally get a lot of "use", and even a broken, rusty, cheap plane can be a cap iron donor.

One thing that occurs to me ('cos I've seen it) from what you describe is that the cap iron has a "saddle back" curve i.e. an upwards curve in its body (not the tightly curved end). If this is the case, some simple pressure should ... bend it back.

As long as the cap iron is a good-ish fit, the lever cap will do the rest, since the cap iron is quite flexible (all things being relative).

BugBear

 

[woodbloke]

much more important is the pressure of the lever cap on to the cap iron thereby pinning the blade down tight to the frog.

I do wish you'd stop advising people to use the pressure of the lever cap to force the blade into contact with the frog, as you've done several times lately. If you need to use a lot of force on the lever cap then it indicates other problems with the plane.

Cheers :wink:

Paul

Paul is absolutely correct. If you really have to force the lever down then it's far too much...I've broken the lever before now with too much pressure. All thats' needed is to make sure that once in place, the iron/breaker combination is held firmly to the frog. If it can be moved from side to side (in other words, it's a tad loose) then the lever cap can be tightened a fraction till it's held securely - Rob

 

[Jacob]

....If you really have to force the lever down then it's far too much...I've broken the lever before now with too much pressure. ,,,,

OK let me explain.
You need as much pressure on the lever as can be done easily WITHOUT GETTING ANYWHERE NEAR TO BREAKING THE LEVER. If you break the lever than that is MUCH TOO MUCH PRESSURE.
If you can't make a reasonable judgement of what is a firm (but reasonable) grip than stick to BU planes - they are relatively ***** proof. Or are they - it'd be quite easy to over tighten the cap iron screw? How do you get on with that?

 

[GazPal]

... If you need to use a lot of force on the lever cap then it indicates other problems with the plane.

Cheers :wink:

Paul

If you don't use enough force then you will have problems. Within reason of course - just firmly clipped down.
I keep going on about it because others keep going on about problems with cap irons, which in my view are easy to fix.
3 or 4 people have raised the issue recently. I didn't know people found them so problematic.

Aye, but excessive, unnecessary pressure via the lever cap reduces adjustability and can potentially negate the practicality of both lateral and cutter adjuster. Per the lever cap, the difference between too tight and just right can sometimes prove a balancing act in itself. This is quite separate to the function of the cap iron which adds rigidity to the blade and reduces chatter while deflecting shavings.

-------------------

Placing the cap iron in a vise and easing or increasing the bend via leverage or "Hitting it with a hammer" can produce the desired effect of helping things along, but always carry out adjustments in small increments and avoid over dressing the cap iron's leading edge. I much prefer Record/Clifton Stay-Set capping irons in terms of function and haven't had problems losing a deflector, nor had one fall away when fitting or removing a cutting iron. :?

 

[Paul Chapman]

....If you really have to force the lever down then it's far too much...I've broken the lever before now with too much pressure. ,,,,

OK let me explain.
You need as much pressure on the lever as can be done easily WITHOUT GETTING ANYWHERE NEAR TO BREAKING THE LEVER. If you break the lever than that is MUCH TOO MUCH PRESSURE.

So good of you to explain that, Jacob. I'm sure we'd have never worked that out for ourselves..... :roll:

Cheers :wink:

Paul

 

[Jacob]

....If you really have to force the lever down then it's far too much...I've broken the lever before now with too much pressure. ,,,,

OK let me explain.
You need as much pressure on the lever as can be done easily WITHOUT GETTING ANYWHERE NEAR TO BREAKING THE LEVER. If you break the lever than that is MUCH TOO MUCH PRESSURE.

So good of you to explain that, Jacob. I'm sure we'd have never worked that out for ourselves..... :roll:

Cheers :wink:

Paul

That's what I realised. Hope that was helpful. :lol: :lol:

 

[bosshogg]

 

[Tony Spear]

....If you really have to force the lever down then it's far too much...I've broken the lever before now with too much pressure. ,,,,

OK let me explain.
You need as much pressure on the lever as can be done easily WITHOUT GETTING ANYWHERE NEAR TO BREAKING THE LEVER. If you break the lever than that is MUCH TOO MUCH PRESSURE.

That reminds me of my chilhood!

(In another context) "Grandad, how much should I tighten this nut?"
Reply "Just until the bolt nearly breaks!"

 

[baldpate]

H again,

this morning, a bit of careful bending (aka 'a few whacks' ), combined with some light work on the front edge of the cap-iron with a diamond stone, seems to have done the trick. I also adjusted the frog slightly to close up the mouth a bit more.

Anyway, the end result is now a very usable plane which is taking nice thin shavings with little effort. And I've learned a thing or two about cap irons into the bargain.

So thanks to everybody for the advice and information.

Chris

PS: particular thanks to Mr bugbear - you were spot on about the "saddle-back curve" - I hadn't noticed it before. It was your post above all that convinced me I hadn't perhaps taken so much material off as to make it irrecoverable, and that the 'bend it a bit'approach was worth a try.

 

[bugbear]

That reminds me of my chilhood!

(In another context) "Grandad, how much should I tighten this nut?"
Reply "Just until the bolt nearly breaks!"

I am reminded of a poem:

Timing Toast

There’s an art to do it.
Never try to guess.
Toast until it smokes,
Then 20 second less.

--Pier Hein


BugBear

 

[Jacob]

That reminds me of my chilhood!

(In another context) "Grandad, how much should I tighten this nut?"
Reply "Just until the bolt nearly breaks!"

I am reminded of a poem:

Timing Toast

There’s an art to do it.
Never try to guess.
Toast until it smokes,
Then 20 second less.

--Pier Hein


BugBear

:lol:
In our house we set fire to it then scrape it. The tricky bit is to not leave it burning for too long.

 

[jimi43]

....If you really have to force the lever down then it's far too much...I've broken the lever before now with too much pressure. ,,,,

OK let me explain.
You need as much pressure on the lever as can be done easily WITHOUT GETTING ANYWHERE NEAR TO BREAKING THE LEVER. If you break the lever than that is MUCH TOO MUCH PRESSURE.

So good of you to explain that, Jacob. I'm sure we'd have never worked that out for ourselves..... :roll:

Cheers :wink:

Paul

I still haven't worked it out...***** that I am! :roll:

So far though...I haven't broken one...even with the full pressure of the Mole wrench brought to bear on it! :lol:


I think I will stick to infills...you only need a hammer to work them there things.... :mrgreen:

Jim

 

[bugbear]

I think I will stick to infills...you only need a hammer to work them there things...

Unless it's a Norris, Holtey, Sauer & Steiner, Entwistle...

BugBear

 

[jimi43]

I think I will stick to infills...you only need a hammer to work them there things...

Unless it's a Norris, Holtey, Sauer & Steiner, Entwistle...

BugBear

For which you need a posh hammer... :mrgreen:

You don't trust that twiddly thing do yer?

Jacob says it doesn't work! 8)

Jim

Jim