Thread: The second edition of my metal plane-making 'manual' is done

Originally Posted by MartinCH

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I also noticed that you have solved the "Stanley no 1"conundrum.

I use a Stanley number 2 a similar way that, but it big compared to your plane. The number 2 come out pretty often in projects.

Martin, if you are alluding to the long-asked question of "What was the #1 intended for?", I don't think I've solved that at all, but I have certainly discovered for myself that a small smoother can be a very handy piece of kit at times, either for working small patches on a large area, or for very small projects. But I've held a #1 in my hands just once, and never got to use it so I can't comment on its usability or usefulness.

I've got 3 small rear-bun smoothers atm (don't ask why!)

Bun smthrs.jpg

The #1 is ~140mm long with a 32mm cutter & weighs 519g (converting from Patrick Leach's numbers). The nearest I have to that would be the plane in the centre above, at 150mm L, 32mm cutter, and weighing 725g. i.e. a bit heavier than the #1. This is a nice little plane with a sweet action, and easy to use:
RB b.jpg

It's slightly larger brother at the top is 170mm long, has a 38mm cutter & weighs a hefty 1025g., which puts in in the #2 range (175mm, 35mm cutter & 1020g, again from Patrick's figures). This is also a very sweet little thing:
RB c.jpg

In fact, I can't decide which of these is my preferred 'keeper' - sometimes I think it's the #1 size, sometimes the #2. I'm sure I could live very happily with one or the other, but every time I decide which is the keeper & which to pass on, I change my mind (which I guess is a good indication there's not a lot of difference!).

A plane about the size of the larger one is what I recommend as your first attempt at a dovetailed body, it doesn't have to be curved, straight sides can look just as handsome with some nice infill wood. The one on the right uses a Veritas adjuster & block-plane blade (made for demonstration for my 'manual'):
Small RB smthrs.jpg

This size takes very little material, you can use a standard block plane blade (or as I have suggested, the Veritas small plane kit ) and it's a manageable project - not too much cutting & filing compared with a larger plane.

You can go smaller, of course, but cutting & fitting tiny dovetails is a bit more fiddly & maybe not the best choice for your first attempt. The smallest double-iron planes I've made are 110 & 125mm long respectively, with ~20mm cutters:
Mini smthrs.jpg

Of these the bun-style is quite comfy to use despite its size & very handy for small work:
RB a.jpg

The other was made purely for fun, as part of a chest of "turn of the century' tools I made during one of the lock-downs. It's usable, but not comfy:
Handled smthr.jpg

It's about 20mm shorter than the #1 & weighs in at 475g, so also a bit lighter, but I would pick the rear-bun plane any day for serious work. Which does make me wonder what a #1 would be like in the real world.....

Cheers,

Small plane are handy IMO as well. It rare in project that I don't reach for the number 2 plane for some aspect. If I have problem area, the last thing I want to do is shave any more than area to clean up. Too likely I find "new problem" areas and so the loop starts.

But this use of small planes with chipbreakers to smooth restricted areas does point to one of the main issues with number 1 as a user plane - that is that there is no use.


While on this topic, of why planes are what they are, /I am of the opinion that curved coffin plane had a propose. They put a wider blade closer to surface - as the sole was smaller, such would not see some undulations that a square plane would see. This allowed a user to smooth to acceptable level just that little bit faster, particularly if there was only one plane at your disposal. I don't know for sure as haven't researched but I assume payment was tied to parts produced and one or two more parts per day would justify rounding the sides.

The difference I concede would be small and I also have the luxury of multiple planes to chase small spots when needed.


PS- each one of little planes is delight - I can imagine few reasons why you have three, sometimes things just need to made.

Originally Posted by MartinCH

....../I am of the opinion that curved coffin plane had a propose. They put a wider blade closer to surface - as the sole was smaller, such would not see some undulations that a square plane would see. This allowed a user to smooth to acceptable level just that little bit faster, particularly if there was only one plane at your disposal....

Martin, that's a plausible idea, though I'm not sure how much curved sides lets you work into a dip - sole length would be the major determinant of how tight a radius of dip you can manage, imo.

I had a long prattle in my original 'manual' on curved sides in chapter 3 where I discuss design considerations, but edited it down to a few sentences. I've done as much reading as I can find on the topic & as far as I can discover, there is no clear functional advantage of curved over straight sides. Curved sides do add a little stiffness to the body, which begs the question of why the larger panel & jointer planes were always parallel sided (I'd think they need as much stiffness as possible), but the only longer planes I've seen with curved sides are some of Konrad Sauer's (and they are gorgeous-looking things!). My conclusion is they were simply following tradition - the 'coffin' shape had been used on wooden smoothers for centuries before Spiers et al started making bench planes in metal. Of course, you then immediately say, aha, there must have been a reason for that, and again I've read a couple of suggestions, the most common being it was to reduce weight & to reduce friction. But wooden soles have little friction & the weight saving isn't huge, & again, if those were the reasons then why were longer planes invariably parallel-sided?

I can tell you from experience that there is one disadvantage to the coffin shape, it makes them easier to tip when you are using it at a skew, as one often does, and the smaller the plane, the easier it tips. Not such a disaster with wooden bodies, but it's a good reason to make sure you put a goodly round chamfer on the sides of your metal plane - a sharp corner can put a nasty little crescent in soft woods like cedar, damhik!

So after much thought on the topic, I've concluded that the coffin shape is more about appearance than function, but I'd be happy to be persuaded otherwise....

Ian

Thanks so much. This is bloody brilliant!

Sent from my Pixel 6 Pro using Tapatalk

Hi Ian

"the most common being it was to reduce weight & to reduce friction"

It is a safe bet it was not for friction
-Friction force

	=	friction force
	=	coefficient of friction
	=	normal force

No area in friction force calculations, unless you account for the small weight change


"Curved sides do add a little stiffness to the body, which begs the question of why the larger panel & jointer planes were always parallel sided (I'd think they need as much stiffness as possible)"

That the panel and jointer planes need to see undulations as their purpose of flattening. Form following function, at least for enduring designs.

PS - not trying to be OTT. When I first encountered coffin planes, I considered for moment or two what was the functional advantage that kept the design alive.

Originally Posted by MartinCH

....
PS - not trying to be OTT. When I first encountered coffin planes, I considered for moment or two what was the functional advantage that kept the design alive.....

Martin, I'm still considering the matter after 60 years.....

One thing is for sure, traditions tend to die very slowly. Lever caps appeared very early on infills, and even on planes without screw adjusters (which Spiers never fitted to infills), they are undoubtedly more convenient. Yet right to the end of the infill era, you could still order wedged planes instead of lever-caps on some models, including mitre planes - the metal plane with the longest history & tradition.

The 'coffin' shape was established long before metal bench planes came along, but the first metal bench planes made in quantity (the 'box mitre' style), were very plain & regular, possibly due to the more limited materials & tools available to early makers but I wouldn't extend that argument too far, as some continental 16thC all-metal planes were quite elaborate, and smiths had been a pretty skilled bunch since before mediaeval times. So perhaps the plain "English" mitre was more about economy of manufacture & keeping them affordable in a market where buying ready-made planes was still pretty novel.

By the time the infill as we know it arrived on the scene, (at least 100 years later, sometime in the 1840s), available materials had advanced considerably, sand-casting had developed to a very high degree, & tools like files & hacksaw blades had probably become cheaper & more reliable, so it would have been far less difficult to build a body in the traditional coffin shape, either cast (as the first infills were,) or by fabricating. It always pays to offer the customers goods they easily recognise!

However, there is a slight additional cost to making a curved-sided plane, due to the extra steps involved in making & fitting the curved side and fitting the stuffing. For a long time (possibly 'til the end), Spiers offered equivalent smoothers with straight or curved sides, with curves costing you a shilling or two extra, & some proportion of buyers didn't think the extra cost was justifiable & stuck with 'square'. The later Norris catalogues have only curved-sided smoothers, so presumably curves had triumphed over straight by the turn of the century.

There are many aspects of tool culture that interest & baffle me. Why, for example, do the British infills have relatively short 'toes' compared with the contemporaneous American Baileys? The short toe allows the plane to follow a slight dip better, but a person new to planes will find the longer toe easier to start without sniping. One side of the Atlantic went one way, t'other side chose a different route - reasons??

As far as I'm concerned, all of the arguments I've seen advanced for advantages of curved sides are falsifiable, so for now, I'll stick with the hypothesis that it's more about aesthetics than function. I do think curves add to the appeal of the infill (to some eyes, at least) but I reckon my straight-sided infills of equivalent size & mass are every bit as functional as my curvy ones....

c.jpg


Cheers,

Yes, well, tools - we do buy, duplicate on the thin premise that someone else has solved all the problems. Faith indeed.

It is fortunate indeed, we don't need to make living from one plane smoothing saw marks off kilometres of skirting boards.