> On Jun 24, 2020, at 16:50 , dks@t... wrote:
> 
> 
> Many years ago, on a work-related trip abroad, I visited London markets at
Penny Lane and Bermondsey. I was feeling flush, and chanced upon a Spiers panel
plane at a price I won't mention. This is a worker plane, not a collector's
item, fitted with a 2-1/2in Sorby iron. I scraped the bottom a little to flatten
it out, and have used it from time to time when it seemed the right thing to do.
But I have always been vaguely dissatisfied with its performance, or perhaps, my
own performance with it.

Sounds like my first infill plane, a no-name smoother I bought from the Merchant
of Ashby. "Vaguely dissatisfied" describes my experience with pretty much every
tool that I thought would cure my tearout problems forever, but there's always
one more tool or tweak to try.

> At any rate, more recently, I chanced upon a Marples iron and cap to fit it,
and picked it up for no special reason except the coincidence of our meeting.
Yesterday I compared the two irons and found, among other things, the Sorby has
a primary bevel of about 27deg., and the Marples a little larger yet. I decided
to grind Marples down to 25deg, my favoured primary bevel, which I finished just
in time to send this msg off and cleanup for dinner.
> 
> SO, here's the question. What primary bevel angle was historically or is
currently favoured for these beefy cutters? Have I made a mistake by grinding
the Marples primary down to 25deg., or could it go even lower?

Catching up on email, I noticed that no one had responded to this, so I'll
offload some of my ignorance here. I grind mine somewhere between 25-30˚, but
can't say if that's historically favored; it's typical on the secondhand planes
I've bought. For a common pitch plane with 45˚ bed angle, that should give you
plenty of clearance, and generally the older steels like O1 or W1 take a fine
edge down to 25˚ (unlike modern A2). For York pitch, you can use a more obtuse
bevel, which I suspect would give you a longer-lasting edge.

Adam