Plane sole lapping the easy way

[JohnCee]

I just had a response from Ray Isles regarding surface grinding of a #7 sole. £22.50 plus VAT, and shipping each way. So I reckon £33 all told. They'll do the sides too for another £7.50 plus VAT

Yes, but where's the fun in that?

 

[sploo]

After restoring one too many old planes, I built a belt sander using a platen of (supposedly very flat) tool steel. I consider that to be lapping the easy way

 

[Jacob]

After restoring one too many old planes, I built a belt sander using a platen of (supposedly very flat) tool steel. I consider that to be lapping the easy way

Yebbut that's cheating!
Do you get a perfect flat surface such as would satisfy the Manic Sharpening Preachers? Feeler gauges etc?

 

[hlvd]

After restoring one too many old planes, I built a belt sander using a platen of (supposedly very flat) tool steel. I consider that to be lapping the easy way

How accurate is that? Reason I ask is that I've tried it with the belt sander at work but it tends to take more off the edges.
I did look at a Paul Sellers video, and he even goes to the trouble of creating this unevenness, so not sure if it's a good or bad thing.

 

[sploo]

Yebbut that's cheating!
Do you get a perfect flat surface such as would satisfy the committed sharpen and polish crew?

They're flat enough such that my limited talent with a hand plane doesn't notice any problems

How accurate is that? Reason I ask is that I've tried it with the belt sander at work but it tends to take more off the edges.
I did look at a Paul Sellers video, and he even goes to the trouble of creating this unevenness, so not sure if it's a good or bad thing.

I can't remember the exact size of the platen (not at home at the moment to go and measure it) but it'll comfortably take a #4 or #5, with just the larger planes needing to be moved across the platen to surface all the sole.

Certainly if you were clumsy in bringing down a plane on a corner when using a low grit it'd do damage, but I've found it fairly easy to get a plane on and off and keep it flat (mostly because the platen is quite large).

Contrary to Jacob, I do like to go to the finer grits, and even a polish, as I'd swear I've found the planes glide more easily when polished up (but I accept it could be just my imagination).

 

[Phil Pascoe]

I flattened a smoother perfectly adequately on a 12" MDF disc with 80 grit stuck to it on my lathe.

 

[D_W]

A belt sander with a really flat platen and a lot of belt tension could absolutely do crude but functional flattening of a plane bottom (be sparing if you like the plane, though).

The hard thing for the average person to do is find a belt sander with a flat enough platen and enough belt tension.

I use a belt sander to flatten the backs of my chisels initially - it's only a step up from the 4x36 belt drive cheapies - it does leave the backs slightly convex (which I hand lap out afterward), but someone carrying a block plane around to trim may not care (or a smoother).

it would probably only be true smoothing work (finish smoothing) where you notice a difference.

There's at least one very high end boutique marking tool maker doing the surface finishing with a low speed high tension belt sander (not contending the straight edge surfaces are done this way, but they may be mostly done at first like that).

The spot method with a scraper/file or small block is the only way someone is going to get a longer plane really flat, though, unless lucky enough to start up with something biased toward flatness when lapped (toes low, etc). Not everyone is going to care if a plane is actually flat if it's working, though - especially if they use power tools 95% of the time.

 

[paulrbarnard]

After restoring one too many old planes, I built a belt sander using a platen of (supposedly very flat) tool steel. I consider that to be lapping the easy way

When I was building a lot of planes I had a large industrial belt sander. It had a wide cast iron bed and comfortably handled a jointer plane. The belts were six inches wide. It made lapping soles and, with its fence, squaring up the sides a really pleasure. The planes were all infill with steel sole and sides so quite a bit of work required in the finishing.
I’ve got a jointer to build up for myself at some point but no longer have the belt sander. Perhaps making something up like you did it the way to go.

 

[sploo]

A belt sander with a really flat platen and a lot of belt tension could absolutely do crude but functional flattening of a plane bottom (be sparing if you like the plane, though).

The hard thing for the average person to do is find a belt sander with a flat enough platen and enough belt tension.

Agreed. I used Matthias Wandel's belt sander plans (Homemade belt sander) for the rollers, and tensioning and tracking mechanism. If I recall correctly, I may have used a slightly smaller roller diameter in order to extend the distance between the two rollers slightly. I bought a 6mm plate of tool steel, guaranteed flat to <some decent tolerance I can't recall right now> and used that as the platen. The sander itself is actually powered by my lathe, and hooks onto the ways for support.

Maybe because I was a bit cheap with the belts, but I do find that even a coarse grit belt wears out pretty quickly; such that the initial lapping of a "batch" of plane soles is just enough to remove the worst of any rust or unevenness (before the belt is useless). I go through a couple of finer grits on the sander, before a "polish" with a few finest grits by hand. Quite some time since I've done it though.