Plane grooves

[Tom Krueger]

Could someone please answer a question for me? A few years ago, I bought a box of old planes and chisels from a friend. He said he didn't know much about them, that they used to be his grandfathers. Offered him 50 bucks, and he took it. There is a couple planes around 8 or 10 inches long, one block plane that's missing parts, and two really big ones ( one around 18" and one around 20"). The biggest one is around 2 1/2" wide and has grooves on the bottom ( craftsman marked). What is the propose of the grooves?
Thanks!

[Jim Koepke]

The theory is the grooves or corrugations reduce the friction on resinous woods. Some planes have them some do not. Some folks prefer corrugations, some do not.

jtk

[steven c newman]

Like these?
scrub jack.jpg
If so...Stanley Marketing Hype.....supposed to reduce drag when planning resinous woods. Hype.

I have all the way up to a 20" long #7c plane.....haven't noticed any difference.

It does reduce the iron one would need to lap off, IF the sole needs flattened ( rarely does, though)

Sharpen them up, and put them to work.

[Normand Leblanc]

This video should gives you the answer.


Normand

[Tom Krueger]

Thanks guys. Was kinda wondering if that was the case.

[Bill Houghton]

On a plane used on edges (such as a long plane used to joint edges straight) I find the grooves are a disadvantage, because they can catch the corner of the work, and then the groove steers the plane - like getting a motorcycle or bicycle tire stuck in the trolley tracks.

But that's information more useful when you're buying a plane. You've got the planes, and they'll do fine, grooved or not.

You will, incidentally, see references to corrugated soles - same thing.

[george wilson]

I hate the grooves. They DO catch on the corners and edges of the wood. I have known for many decades that they DO NOT decrease friction. Simple reasoning shows that they do not. You have the weight of the plane plus pushing it to some degree downward while planing,on a smaller surface. That is bound to increase friction.

[Patrick Chase]

I hate the grooves. They DO catch on the corners and edges of the wood. I have known for many decades that they DO NOT decrease friction. Simple reasoning shows that they do not. You have the weight of the plane plus pushing it to some degree downward while planing,on a smaller surface. That is bound to increase friction.

Exactly. Under the simple model of dry friction all that matters is the total downforce, not the area over which it is applied. For dry friction corrugation makes no difference either way.

Where structure (grooves, tread etc) matters is in when there is free water at the interface, and "sheeting" and therefore suction is a concern. In that case a grooved or otherwise noncontinuous surface can help a lot, but that's not how planing works.

[steven c newman]

Hmmm, remember this. Since the toe, heel and both sides of the mouth opening are NOT grooved....means they ( if they are coplanar) contact a surface before the grooves can....

The only thing I've ever "caught" with the grooves on the planes I use? IF the side of my index finger gets in the way, as I drop the fingers under the plane when jointing an edge. IF they get caught, means the plane was moving a bit side to side.

Been using a Stanley #7c (2 of them) a Stanley #6c, and a Stanley #5c. That be the one in the picture I posted above.

IF the grooves really did anything....L-N would have copied that feature on their planes.....

[Bill Houghton]

Exactly. Under the simple model of dry friction all that matters is the total downforce, not the area over which it is applied. For dry friction corrugation makes no difference either way.

Where structure (grooves, tread etc) matters is in when there is free water at the interface, and "sheeting" and therefore suction is a concern. In that case a grooved or otherwise noncontinuous surface can help a lot, but that's not how planing works.

So, anyone who does a lot of planing underwater or during heavy rainstorms should buy corrugated-sole planes?

[Patrick Chase]

So, anyone who does a lot of planing underwater or during heavy rainstorms should buy corrugated-sole planes?

Rainstorms, yes. Underwater it probably wouldn't help, since there's no air to be had anyway ("probably" because I'm too lazy to work through purely viscous friction for that configuration).

[Ryan Mooney]

I think they mostly sold because it was in the era where everything was just groovy man.


I'll show myself out..

[glenn bradley]

...Stanley Marketing Hype....

The hype worked since many makers made corrugated soles . I have a MF #9 and a #9c. I use the smooth bottomed one as a smoother with a cambered blade and the other one for light stock removal. I prefer to grooves but that don't mean I ain't "groovey".

[Stewie Simpson]

Putting aside the hype about the reasoning behind the corrugated grooves, they are as good plane to use for primary face work. The corrugates also make the task of flattening the sole less time consuming. As to why LN and the big V haven't introduced corrugated soles, give them time, they have copied every other Stanley and Bailey patent so far.

[Andrew Gibson]

I collect corrugated bench planes as my primary qualifier. The reason is that the first plane in my collection was a #7 Union that belonged to my Grandfather. From that point forward I always looked for the corrugated souls. Brand is not typically a concern, I have Union, Stanley, Sargent, and Fulton in my modest collection. I have #3 through #8 and missing a #5-1/4C and a 5#1/2C. I only have duplicate #5's, set up for coarse and fine work respectively. I do have a pair of #4's but one is a LN bronze and not corrugated.