Scrub plane project

[rxh]

For my next plane building effort I am considering making a scrub plane. I have chosen most of the measurements but one dimension that I am undecided about is the distance from the blade cutting edge to the front of the mouth, i.e. the width of the gap that the shavings will pass through. I imagine that this is not critical provided it is on the generous side but I’d be grateful if any scrub plane owners can tell me the corresponding dimension on their plane and whether they find it satisfactory.

 

[Jacob]

For my next plane building effort I am considering making a scrub plane. I have chosen most of the measurements but one dimension that I am undecided about is the distance from the blade cutting edge to the front of the mouth, i.e. the width of the gap that the shavings will pass through. I imagine that this is not critical provided it is on the generous side but I’d be grateful if any scrub plane owners can tell me the corresponding dimension on their plane and whether they find it satisfactory.

I have an ECE scrub. The mouth was about 5mm as far as I recall. I enlarged it in a curve to more or less match the blade and it cuts a lot better. Probably about 10mm at the furthest point. I'll dig it out and have a measure.

 

[bugbear]

Measuring rhe mouth of a scrub is a little interesting, since the normal use of the plane has far more blade projection that other planes.

For simplicity, I measured my scrub plane with the blade set to 0 projection (i.e. flush with the sole) the mouth is only 4mm, but in a curve parallel with the blade edge.

But it passed these shavings (chips?) and has never jammed or clogged.

BugBear

 

[Cheshirechappie]

I've had a Lie-Nielsen scrub since they were first available in the UK; it can do a lot of damage to a piece of timber very quickly! The mouth from blade tip to front edge is just over 3/16", the full mouth opening with blade out of the way is 7/16". The blade is 1 1/2" wide, 3/16" thick, and has a 3/32" camber.

 

[Corneel]

Mine has a straight mouth (narrow German wooden scrub). It varies from 4 to 6 mm. Never problems with choking.

 

[rxh]

Thanks for your replies gentlemen. Good agreement here - I propose to make it about 5 mm (or 3/16").

Here is a preliminary drawing. The blade would be 1 1/2" wide and 3/16" thick and made of O1 steel.

A bit OTT to make an infill scrub plane? Possibly so but it will be a way of using a "reject" rear infill and some other leftover parts from earlier projects.

 

[jimi43]

I don't see why the poor old scrub plane can't be posh Richard....and your design is superb (as usual) so I can't wait to see how this one turns out!

Cheers

Jimi

 

[Corneel]

Well, it'll make a dandy scrub plane. But the pleasure of my wooden scrub is its lightness. That makes it possible to get a rhytm going. I don't know if it would be as much fun to use a heavy infill. Here's a video showing what I mean.

https://www.youtube.com/watch?v=LJKa9Czzy3Q

Maybe that sounded a bit too negative. I don't mean it that way, I very much like these kinds of user build tools. It's just a warning, brought from my own experience.

 

[rxh]

Thanks Jimi and Corneel.

Corneel,
I watched your video with great interest. This helps my education as scrub planes are new to me. I'm tempted to have a go at making a woodie scrub too, using the same blade size and general geometry as the infill one. Then it will be interesting to see how they compare and it will be an opportunity for me to attempt traditional style wooden plane making, which I haven't tried before.

 

[Corneel]

Good luck! On both adventures.

 

[Shrubby]

Corneel,s video shows perfectly why the best scrub planes are lighter wooden bodies. Thrashing back and forth with an infill will quickly exhaust you
My scrub is a German woody from a flea market
Matt

 

[rxh]

Corneel,s video shows perfectly why the best scrub planes are lighter wooden bodies. Thrashing back and forth with an infill will quickly exhaust you
My scrub is a German woody from a flea market
Matt

Thanks Matt, that's an interesting point. Would any users of metal scrub planes (purpose built or converted No. 4s) like to comment?

 

[Jacob]

Metal scrubs are scarce (not counting the modern LN/LV offerings - which are oddities) probably because they didn't catch on. I guess it was because of the weight (and the price).
OTOH the light woodies are a pleasure to use and remove a lot of wood very fast. Light weight, lighter work.

 

[tobytools]

wow, great idea richard. next you have to make a infill moulding plane body with interchangable profiled soles and irons (h&r beads ECT)
now that would be the balls
what wood will you use

all the best
TT

 

[Cheshirechappie]

Metal scrubs are scarce (not counting the modern LN/LV offerings - which are oddities) probably because they didn't catch on. I guess it was because of the weight (and the price).
OTOH the light woodies are a pleasure to use and remove a lot of wood very fast. Light weight, lighter work.

I wonder whether metal scrub planes in the UK at least, didn't catch on in the late 19th/early 20th century because everybody had access to older woodies to modify into 'fore planes' if they needed one.

The weight claim slightly surprised me, since I'd never noticed the LN scrub being 'heavy' to use - rather the reverse, in fact. In comparison to most planes, wood and metal, it feels quite light. Just out of interest, I weighed it (the wierd things I do for this forum!) and it's 2lb 10oz. For comparison, I weighed a small woody smoother (7 1/2" body, 2" iron) which came in at 2lb 2oz. Both of those are well to the 'light' end of the bench-plane scale.

I can't imagine a circumstance in which one would use a scrub for an extended period, given that they shift a lot of wood very fast - if there's so much to remove, you'd either choose thinner stock to start with, or saw most of it off. I've certainly never suffered fatigue whilst scrubbing, since the job is done before fatigue sets in. Trying-up stock is another matter - that can sometimes take quite a long time with a big, heavy plane, and pacing yourself can be a necessity after a while.

If making an 'infill scrub', I might be tempted to use stock steel for the sole and sides a bit thinner than usual for an infill - say 1/8" sole and 3/32" or even 1/16" sides. That should give a body that's light but more than strong enough for duty, given that absolute flatness and straightness are not really needed in a scrub, and neither is the 'heft' of an infill smoother or panel plane.

Edit to add:

Just watched Corneel's video. He tends to use the scrub rather faster than I do; I tend to assess where the humps are and take the highest spots off, assess again - and so on. I probably use a stroke rate about half his, with a depth of cut depending on what the wood will allow for a reasonably easy stroke with maximum stock removal, and on how much needs to come off. (I don't often have boards that big to work - if I did, I'd pace myself a bit!). By the way - that is in no way a criticism of Corneel - different approaches suit different people, and judging by the heaps of chips, his technique works fine for him!

 

[Paul Chapman]

Would any users of metal scrub planes (purpose built or converted No. 4s) like to comment?

I use a metal scrub plane - the Veritas scrub. I do all my stock preparation by hand, so use it a lot.

I've never bought into the view that scrub planes must be light to work effectively or that they should be used in a fast and frantic way. With any planing, you need some downward pressure so, in general, I prefer heavier planes. And with scrubbing, you are usually removing a lot of material so the less downward pressure that is provided by the plane, the more that has to be exerted by the user.

As far as planing fast you can, of course, plane as fast or as slow as you wish - it's not a race :lol:

Cheers :wink:

Paul

 

[MIGNAL]

It depends on your individual circumstances. I don't have a scrub plane but I do use heavily cambered irons on metal and wooden Planes. I refer to them as being gentle scrub Planes. You certainly can get a lot more done when using a wooden Plane, especially so on European medium density hardwoods. Quite simply they are less tiring to use. Of course if you only have to use a scrub plane for 10 minutes you aren't really going to notice it much. If you have a series of boards to do I think the difference becomes very apparent.

 

[Corneel]

As you can see in the video, that was a large board. And I needed to remove from 3 to 8 mm in the thicknessing phase to make it the same thickness as another board for a dinig room table. When thicknessing you remove a lot of material and the scrub is a life saver for that kind of work on such a scale. Next step is the fore plane and then a jointer. These steps actually take a lot more time then the scrubbing, while you remove less wood.

I am not a big strong guy, so I use speed to be able to remove a decent chip.

I wonder how they would have done this back in the days when they didn't have large planers yet. I think they would have used an adze or a broad axe on smaller boards.

 

[Cheshirechappie]

I wonder how they would have done this back in the days when they didn't have large planers yet. I think they would have used an adze or a broad axe on smaller boards.

I'm not sure there's a single 'right' answer to that. For some tasks, they'd have sawn logs to the thickness they wanted, and in some cases they'd have used the thickness that was there. Perhaps were boards were riven from the log, they'd have tidied up the surface with broad-axe and adze, finishing with planes.

I suspect approach depended a bit on the work in hand. For furniture, they tended to use the thickness of wood as sawn, and not thin it down at all; sometimes they didn't even bother to plane up surfaces that didn't show. There are 15th century oak tables in large houses with tops 3" or so thick - whether riven or sawn I don't know - but I'm willing to bet they just got the top and bottom flat, and the top smooth, and didn't bother about thicknessing it to a given dimension. Other trades (coopers and wheelwrights, for example) would have shaped up their components from stock with side-axe, drawknife, etc. Shipwrights, as we know, were adept with the adze.

 

[Corneel]

My problem was that the design asked for a quite modern look, with straight boards and the boards as they were had cupped considerably. And one board more then the other of course. Over 50 cm width, a bit of cupping can mean a lot of scrubbing!

I've also seen tables from the middle ages where the stretchers of the under cariage where more or less "mortised" into the top. They would chop out recesses until the table could stand on its legs without wobbling. But I didn't want that kind of look which looks a bit rough. Maybe if I had known about the amount of work I would have changed my mind...