Derek Cohen (in Perth, Australia)
Hi Mark

I agree with your comments about a smooth, flat leading edge to the mouth. If there are chips or depressions, then this can be a cause of tearout. If there are striations, it can affect the shaving (I am not sure if this is so here, because this is how Tasmanian Oak shavings typically appear).

It would seem to me that a high angle bed is going in the wrong direction, and would seem to me to be pushing and scraping the wood more than cutting. And although it may not cause tearout it is probably not going to give you as good a surface.

So looking at this from a logical, observational perspective, high bed angle never made any sense to me.

Having used supersurfacers and handplanes for many years,I am quite sure that low bed angle works quite well. So its not just an opinion without any backup.

I have many years experience using planes with high beds and/or high cutting angles. I understand the view that they scrape rather than slice. Nevertheless they can and do produce a very smooth, if not reflective surface, in hardwoods. In the Australian context, where especially in my neck of the woods, the local fare is interlocked and hard, high angle planes make a lot of sense.

What is old/new is the notion of using the chip breaker to control tear out in a common angle plane. While you say it is old - and I am not questioning this at all - for a great many woodworkers (ask the forum to raise their hands), this is something they have little or no experience in doing. Chip breakers were "cap iron" that only served to stiffen the vibration in a blade. That is, if the performance was improved by a chip breaker, it was because of reducing vibration, per se.

So we are to some extend rediscovering the wheel. However there is more to this than just that. We also know that other strategies improve the performance of planes on interlocked or reversing grain. And this experiment was intended to examine some aspects.

Regards from Perth

Derek