A screwdriver for saws

A couple of weeks back I bought a saw screwdriver from Lee Valley. Made by Grace USA, this screwdriver is made to fit slotted saw screws.

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The handle is made of unfinished hardwood, in a classic style with a square profile with rounded corners. This prevents it rolling off the bench. The driver has a 0.35″ wide tip, which has been ground to a parallel consistency of 0.032″ thick.

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The parallel tip prevents damage which might normally occur due to tapered tips, which fit poorly, and also reduces the screwdriver from slipping and marring the handle of the saw. Here is an example of using the screwdriver in one of the saws I one day hope to restore.

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A well designed screwdriver for the workshop

A couple of years ago I bought a neat screwdriver, after reading about it on the Lost Art Press blog – the No.1 from Element’ary Design in England. The screwdriver is ergonomically designed, with handles made of beech, and finished with linseed oil, giving it a smooth surface.

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Even the box the screwdriver comes in is well designed. I bought mine from Dyke & Dean, in the UK, but Hand-Eye Supply in the US also carry them.

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The shape is perfectly designed to fit inside the palm of your hand. Also, due to the shape, it won’t roll off your workbench.

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The screwdriver is kind-of unique, as it uses interchangeable bits – unique because normally interchangeable drivers are constructed of plastics.. It comes with six bits (two Phillips, two flat heads, two posi-drive), but will use any standard bit.

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The chuck of the screwdriver contains an o-ring, which syncs with the groove found on many bits. In addition however, the screwdriver also has a screw chuck with a knurled grip  that helps lock down the bit. No fear of the bit dropping out, as often happens, even with magnetic bits.

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There is also a stubby version of this screwdriver – the No.2.

The best hand saw for renovation?

When working on renovations around the house, you need tools, but you may not necessarily want to use good woodworking saws for rough work, like cutting plywood, or even 2×4’s. An excellent alternative is what some call the “Japanese plywood saw”. This 240mm pull-saw, made by Japanese company GYOKUCHO, is the RAZORSAW No.S-410.

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The saw is a cross-cut saw, with hardened teeth to deal with the glue found in plywood (17 tpi). It has a blade thickness of 0.6mm, and a tooth pitch of 1.5mm (most of this information is available on the blade itself). This is not a Japanese saw with delicate teeth – it is the workhorse of the toolbox. I have had one for years, and maybe replace the blade every 5 years.

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Around the house it has cut plywood, MDO (medium density overlay), trim, it has  finished saw cuts, and even cut ABS pipe for plumbing. The teeth are impulse hardened to somewhere between Hv900-1200¹.

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Now how does the saw cut? As well as can be expected from a saw designed to cut “rough”. Below is a cut through a piece of poplar, with a blade that is likely 6-7 years old.

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¹Hv is the abbreviation for the Vickers Pyramid Number.Diamond has a Hv value of 10,000.

Defining the ubiquitous block plane

What is the one thing that differentiates the block plane from other planes? Apart from its short length, there is one distinguishing characteristic – they usually have bevel-up blades. So what other characteristics make up a block plane?

1. The blade is bevel up.
This means that the bevel on the planes iron faces up. For the block plane, the angle of the cutting edge to the wood equals the bedding angle plus the blades bevel angle. This concept was also used on planes like the Stanley No.62 and Sargent No.514, and has been adapted for a whole line of “low-angle” and “bevel-up” bench planes fro contemporary tool makers Veritas and Lie Nielsen.

2. There is no cap iron.
The cap iron has two purposes – it supports the cutting iron, making it more rigid, and it helps break and curl the shavings being produced. Due to the low bedding angle, bevel-up blades, and its use on end-grain, there is less need for a cap iron. Ideally the blade in a block plane should be quite thick, to reduce vibration and chatter.

3. The bedding angle of the blade is between 12º and 20°.
This allows for the pitch of the blade to be changed by changing the blade itself. In many older block planes, the bevel angle of the blade is a standard 25°, which could be modified by means of a secondary bevel. Manufacturers such as Veritas also provide blades with bevel angles of 38° and 50° cutting edges. With a 12° bedding angle, this provides pitches of 37°, 50°, and 62°. The 20° bedding angle, provides pitches of 45°, 58°, and 70° respectively. A standard cutting angle of 45° or greater is ideal for using a block plane for long grain, where the fibre will be cut rather than lifted or torn. It requires more effort to push through the wood, but it breaks the chip quite aggressively for a clean cut. Conversely, a low cutting angle reduces friction, and requires less energy to use on end grain, where it slices through the vertical fibres. A block plane with a low cutting angle has problems with high-figured, or difficult grain, because the low angle achieves a knife-like cut, that can lift and tear.

4. The multitude of blade adjustment mechanisms.
On a good block plane it is possible to adjust the depth of cut, lateral adjustment, and size of the mouth. Some of these evolved out of need – a 12° bedding angle required a screw-like blade depth adjustment mechanism due to lack of space.

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The story behind these characteristics?
So, block planes were originally designed for making and re-finishing butchers blocks. Butchers blocks are often made of hardwood such as maple, with the end-grain oriented upwards. Working with these blocks required a lower pitch plane, as a smoothing plane had a blade pitch which would cause the fibre to split. Lowering the bedding angle of the plane resulted in a need for a more acute edge on the blade. It was impossible to lower the bedding angle to a workable pitch without the resulting angle on the blade being far too weak. Subsequently the only feasible way of lowering the bedding angle was to reverse the blade, resulting in a bevel-up blade. This also meant that there was no real need for a cap iron on a block plane.

Therefore the necessity for a low bedding angle induced the need for the blade to be bevel-up, which in turn meant that the cap-iron was superfluous.

Here are some of the general characteristics of a block plane:

plane body: cast iron, pressed steel, aluminum
throat: adjustable or non-adjustable
length: 3½, 5½, 6, 6½, 7
blade width: 1", 1-3/8", 1-5/8"
bedding angle: 12-20º
blade bevel: 25º (standard), up
trimmings: Japanned or nickel plated
front knob: hardwood or metal (brass)
levercap: cam, knuckle, screw-cap
adjustments: throat (mouth size), blade-depth, blade-lateral

 

Woodworking gifts for Xmas? Try retro goggles

Want steampunk safety glasses that look cool? Problem with many safety glasses is that the sides, top and bottom are open – only the front of your eyes are really protected. So on a whim I bought these German safety goggles from Lee Valley (also available from Garrett Wade). They are easy to see through, allowing for 360 degree eye protection, preventing sawdust or chips shooting under the glasses. They have aluminum frames, and are super comfortable.

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Also available from Garrett Wade, and various other places.

An old piece of wood.

Friday we went to the “One of a Kind” , craft fair in downtown Toronto. Woodworking-wise, there is an abundance of exceptional cutting boards (like 10 years ago it was almost impossible to find good handmade cutting boards, now there is a huge selection). What we bought was a stool made from a block of old growth hemlock from the Toronto Ferry Terminal Wharf. As the harbour was reclaimed, the old wharf was filled in. Whilst excavating for re-development in 2007, the wharf was found, and the wood reclaimed (by Urban Tree Salvage).

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Here’s a count of the rings on this block:

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There are over 110 years of growth in the block we bought. These blocks are in great shape, considering hemlock’s low resistance to rot. Who really knows how big the tree actually was.