Thread: Problems hand-planing Australian hardwood

Sole flatness has a huge impact on the performance of a plane. I started woodwork again recently after a break and found I had previously been using a plane with a curve in the sole. A flatter sole made a world of difference.

Derek, I didn't mean the bevel angle of an iron prevented sharpening effectively or that other cutting angles can't be effective. I meant that a 45d bevel with the blade also at 45d means the primary bevel is basically sitting flat on the wood (with no clearance). Regardless of theory or whether it is the issue in this situation I know from personal experience it creates a problem.

Hi Mnb

That is what I thought you meant, and I agree with you. What you are referring to is the absence of the relief angle. There is a minimum for the relief angle to be to allow a plane to cut effectively. This is believed to be around 7 degrees. In other words, a plane with a 45 degree angle frog (or "common" angle) will function effectively with a blade with a bevel to a maximum of 38 degrees. Over this, and the plane stops cutting properly. What is believed to occur is the wood springing back under the blade, and this certainly could create the effect of a plane sliding over the wood. The effect is more so with hard woods. There may be a little wider range with soft woods.

Regards from Perth

Derek

Edit to clarify Stewie's post, below: relief and clearance angle are the same.

Re discussion on lack of clearance angle, the OP had no issues planing softwood.

John Whelan: The Cutting Action of Planes
Although softwoods permit a smaller sharpening angle, they also yield more before being cut and thus require a larger clearance angle

Sorry Derek, my misunderstanding not yours. I'm wrong anyway, I didn't need to look at plane maker's link because it makes total sense. Thanks pm.

Originally Posted by derekcohen

Hi Mnb

That is what I thought you meant, and I agree with you. What you are referring to is the absence of the relief angle. There is a minimum for the relief angle to be to allow a plane to cut effectively. This is believed to be around 7 degrees. In other words, a plane with a 45 degree angle frog (or "common" angle) will function effectively with a blade with a bevel to a maximum of 38 degrees. Over this, and the plane stops cutting properly. What is believed to occur is the wood springing back under the blade, and this certainly could create the effect of a plane sliding over the wood. The effect is more so with hard woods. There may be a little wider range with soft woods.

Regards from Perth

Derek

Edit to clarify Stewie's post, below: relief and clearance angle are the same.

The worlds population is 7.4 billion. Australia's is 24 million and no-one really makes decent planes in Australia. Now think in terms of where planes are made, what wood were they developed to work with and what about whether the angle of the blade is appropriate for Aussie hardwoods. Yep, its all down to the body and the angle in the block plus the blades bevel/relief angle. Our world started in the Northern Hemisphere with wood block planes for wood and here down under we expect ones developed over prior times for Oak, Pine or Hickory etc to work equally well with our Iron Bark? We've got to be bonkers. But then its all hard yacka here. Take a slice from the tree fellas, the ones that felled the trees by axe. Aussie axes had very very thin blades to penetrate the wood with each strike.. imported ones were useless and still are. then there's always the adze as a fall-back. If you can modify the frame and change (lower) the set of the blade you can expect improvement ... otherwise you're stuck with making the blades bevel edge as shallow as possible but not too shallow as you'll spend all your time resharpening. When you're finishing hardwood think of the aussie termite, the crawly thing that chew and make life here problematic. The harder woods they don't touch. Why? Its down to the hard mineral that's drawn up into the wood during slow growth that dulls any edge. Íts called osmosis. Think of dissolved solids in water. In particular silica. Reverse osmosis is a process that uses huge pressures to remove particulates from water while the Osmotic process is the opposite, it harnesses ambient osmotic pressures plus draws water up the height of the tree including its dissolved and undissolved minerals. Maybe this is why we have a tree called an Iron Bark? Then of course remember that grain is never straight and its density varies continuously in every direction. Just think of what the millers have to put up with their discs or bands wandering all over the shop due to grain density and directional variation.
Lastly think of the plane edge... is it the best steel, is it the most appropriate for the job? maybe GOES polycrystalline high silica steel? Then sharpen it at the most appropriate angle for the blade set.

Have a great day. We have a hard life here shut away from the world. Who's going to start making the OZ logic planar? . Is there a market? . Rog

Originally Posted by boulle

The worlds population is 7.4 billion. Australia's is 24 million and no-one really makes decent planes in Australia.

Hello boulle

I don't think there would be too much disagreement with the first part of your statement, but I think you might have a few dissenters with the second comment particularly as Terry Gordon designs his planes with Aussie hardwoods in mind:

https://hntgordon.com.au/

and if you are referring to the antipodes in general and we are allowed to include New Zealand then Philip Marcou's supporters might take up the cudgel too:

Marcou Planes, classic hand planes, Gallery

Then there are a fine bunch of makers who regularly subscribe to this section of the woodwork Forums, but they are admittedly not commercially orientated:

My last & final infill - a dovetail plane

A #3-sized infill coffin smoother

Traditional Stopped Chamfer Plane.

And there are others too, but tea is on the table and I have to go.



Regards
Paul