Plane Flattening, Corrogated or Smooth?

[Stew Denton]

Hi All,

I am thinking about buying a #7 for a gift, and want it to be a really good plane. A Stanley #7, probably a type 10, 11, up to a type 15 or so, something in that vintage, or a 607 would fit the bill. If it could use flattening then it will be sent to Tom to grind flat, unless it is really good "as is."

The question I have is that if it is to be ground flat, does it make any difference if the sole is corrugated or smooth?

Secondly, does it make a lot of difference, in your experience, in use? Do you think one type is especially better than the other? Schwarz mentions in his book on planes that he doesn't see any difference in how tiring one is to use versus the other, but the corrugated planes do hold the wax better. (He thinks that the idea that a corrugated sole plane is easier to push than a flat sole is not really correct, at least it is not true to his experience.)

Thanks and regards,

Stew

[Dave Parkis]

I think you'd be better off sending Tom a PM and asking him about whether one is easier to grind than the other. I check flatness by running a straight edge on both diagonals on the sole and checking to see if any light can be seen. IMHO, as long as its flat at the toe, front/rear of the mouth, and the tail, its probably good. I don't use jointers every day, but I don't see any difference between the soles other than when edge jointing. Then it is possible to run an edge in a groove.

[David Weaver]

If you have a choice, flat bottom (non corrugated). The corrugations don't actually hold wax any better, at least not usable. The only wax of the stiffer type (like paraffin) that actually contacts wood is what's on the metal itself.

I bought corrugated planes when I first started believing that the corrugations would act like a reservoir, but there was no such practical gains, and the corrugations were just better at cutting flakes of wax off of the paraffin bar and wasting it.

They also will get some odd erosion patterns in front of the mouth, though if any of us are using clean wood, it probably wouldn't happen to us.

Otherwise, no practical difference. I'd suspect the corrugations were sold to frustrated woodworkers who liked the precision and ease of the metal planes, but had the slickness of the wood planes fresh in their minds.

One side comment from a long-time user of both wood and metal planes. Wax notwithstanding, we have a tendency to get tired and push down harder. When you're doing heavy work and using a plane, consciously push forward on the back handle instead of down. Quite often you'll find the vast majority of the effort you were making was to overcome the additional friction you're creating from leaning on a plane as you get tired, and that little downpressure is needed if the iron has not lost all of its clearance.

[Bob Jones]

I have a pretty strong preference for non-corregated planes - it makes it easier to sight the blade for setup. I have an even stronger preference for a plane that is inexpensive and in good condition. Make that your first criteria. Hang holes hurt nothing but the sale price.

[Jim Koepke]

Only three of my planes have corrugated soles. If any of my planes are sold off those will be the first three.

My experience has shown no advantage nor disadvantage.

Maybe if you poured melted wax into the corrugations some would be retained...

jtk

[Stew Denton]

Hi Bob,

I am with you. Hang holes are fine with me too, as is patina and even mild surface rust and even very minor pitting if not in critical locations. If I can clean it up with elbow grease, sandpaper, steel wool, paint stripper, naval jelly, metal polish, new finish, etc., and save a few bucks,.......make that quite a few bucks, then I will take it over a pretty one every time. I do want them to look good when I am through working on them though.

Same thing with saws, and other tools as well. Ops, I don't need any more saws.....I keep reminding myself of that.

Jim, I only have one keeper plane that is corrugated, and it was my grandfathers. It's a keeper because it was his, not because it's my best plane, although I have gone to a lot of trouble to chase down parts and restore it, and it now cuts pretty well indeed.

Grandpa's plane and the 605 that was my dads would be the last ones to go.

Stew

[Judson Green]

I'd rather have a smooth bottom plane, but don't feel it matters much and really I just end up with what's available. It would seem to be easier to flatten a corrugated sole using home shop methods vs a smooth sole.

Never understood why it would be advantageous to hold wax deep in the corrugations, and still don't.

[Jim Koepke]

Never understood why it would be advantageous to hold wax deep in the corrugations, and still don't.

It does make it easier to get earwax off of a fingernail.

jtk

[Tom Bussey]

I personally don't think that there is any difference between a flat bottom and a C in use. I think it was a marketing giminic. I don't see where one would hold wax any better than the other.

Being a Tool and Die Maker by trade I do not have any faith in straight edges that people can buy from a local hardwear store as being straight. And if I tried to get by using a feeler gage I would have been laughed at by my peers. Will it give you an idea? answer?

The best thing a person can do with a plane is to clean the bottom with as fine a paper as possible. You don't want a lot of deep scratches in it. Wax the bottom and sharpen the blade as sharp as possible and use it.

I know that everyone knows how to and can flatten them in just a hour or so, but the truth is, don't try to flatten it you are not professionaly trained. 99% the planes I get after people have tried to flatten them and are worse than if they were left alone. Also most of the ones I see are high in the middle. Everyone wants the real thin shavings. The cut is started with pressure on the front knob and as the pressure is shifted to the tote the chip brakes. Why, because the plane rocks. Lie Nielsen and Lee Valley planes are well thought of and are well respected. Why because the work. The are flat and the bottoms are really smooth so there is as little friction as possible and it take less work to get them to cut. I will let others say if mine cut or not.

Tom,

[Jim Koepke]

99% the planes I get after people have tried to flatten them and are worse than if they were left alone.

Most likely the reason most planes people buy second hand are not flat is because somewhere along the line someone got bit by the must lap all plane sole bug.

jtk

[David Weaver]

I know that everyone knows how to and can flatten them in just a hour or so, but the truth is, don't try to flatten it you are not professionaly trained.

This is completely inaccurate advice and has only an entire century and a half+ of practical use of metal planes from people actually making things to go against. Anyone on this board can accurately flatten a plane with $20 worth of glass and a few $ worth of PSA sandpaper rolls ($3 worth can literally flatten 4 or 5 smoothers to jacks, and most metal jointers).

If someone wants to get their planes ground so that they have the flatness tolerance of LN or LV, that's fine, but to suggest that it's necessity that they don't do it themselves is very poor advice, and if someone cares about the cost, it's also a waste of money.

I have a mechanical engineer friend who suggests the same, that flattening must be done by surface grinders, etc, but he has very little experience using hand tools. The finest work has been done before LN and LV came along with catalog flatness spec. The same friend has a dial indicator setup on his thickness planer so he can get his boards just how he likes them.

The practical fact is that judicious lapping will make a plane slightly convex, which is exactly what a skilled hand tool user would want to plane a sprung joint. I just checked the only metal jointer I have left, a millers falls 22. I can get a sheet of 20 pound paper between a starrett 380 (that I bought new and have never abused or dropped) and the sole of the plane for the last approximately one to 1 1/2 inches of the plane on each end. I can see light before that, but not enough to get a sheet of paper through.

The precise reason I have only one metal plane left is because I had LN's jointers (both the 7 and 8), and saw no practical difference in making a 4 foot sprung joint with them vs a lapped stanley jointer (or millers falls in this case). I work mostly with hand tools from rough lumber. My wooden try planes are about the same length as the millers falls, less flat, and still, no trouble making a four foot sprung joint that closes with very little hand pressure.

If a few people screw up planes because they have no idea what they're doing, it doesn't negate 150 years of practical use.

[Bill Houghton]

For a No. 7, which you'll be using at least sometimes for edge planing, I'd walk past the corrugated planes and get a smooth one. The corrugations can catch on the arris - corner - of the stock, and "track" the plane off course, a little bit like riding a motorcycle on a rutted road, although less likely to cause great bodily harm. But very frustrating. If I got the chance to replace my corrugated No. 8 with a smooth one of the same vintage, I'd do it in a shot.

Oh, and: don't assume you'll have to send it out for grinding. Test it first.

[Mark Engel]

This is completely inaccurate advice and has only an entire century and a half+ of practical use of metal planes from people actually making things to go against. Anyone on this board can accurately flatten a plane with $20 worth of glass and a few $ worth of PSA sandpaper rolls ($3 worth can literally flatten 4 or 5 smoothers to jacks, and most metal jointers).

If someone wants to get their planes ground so that they have the flatness tolerance of LN or LV, that's fine, but to suggest that it's necessity that they don't do it themselves is very poor advice, and if someone cares about the cost, it's also a waste of money.

I have a mechanical engineer friend who suggests the same, that flattening must be done by surface grinders, etc, but he has very little experience using hand tools. The finest work has been done before LN and LV came along with catalog flatness spec. The same friend has a dial indicator setup on his thickness planer so he can get his boards just how he likes them.

The practical fact is that judicious lapping will make a plane slightly convex, which is exactly what a skilled hand tool user would want to plane a sprung joint. I just checked the only metal jointer I have left, a millers falls 22. I can get a sheet of 20 pound paper between a starrett 380 (that I bought new and have never abused or dropped) and the sole of the plane for the last approximately one to 1 1/2 inches of the plane on each end. I can see light before that, but not enough to get a sheet of paper through.

The precise reason I have only one metal plane left is because I had LN's jointers (both the 7 and 8), and saw no practical difference in making a 4 foot sprung joint with them and a lapped stanley jointer (or millers falls in this case). I work mostly with hand tools from rough lumber. My wooden try planes are about the same length as the millers falls, less flat, and still, no trouble making a four foot sprung joint that closes with very little hand pressure.

If a few people screw up planes because they have no idea what they're doing, it doesn't negate 150 years of practical use.

Yup. .

[Adam Cruea]

I have a corrugated and smooth bottom of both jointers (8 and 7).

Reason? Easily distinguishable for me. I just run a finger across the bottom on the heel of the plane, and I know which plane takes a heavy shaving vs. which plane takes a light shaving.

Other than that, there's no real distinguishable difference between the two.

And Mr. Weaver. . .keep in mind, you're smarter than the average bear. Average intelligence people probably screw up more planes than Tom can describe due to thinking they can do things because they've heard someone like Tommy Mac say you can just slap sandpaper on a benchtop and go to town. A lot of people can't grasp that their benchtops aren't flat vs. a slab of granite, or floated glass, or a cast iron top.

[David Weaver]

Right, you do have to do it correctly, which involves getting something flat and then lapping only as much as you need to. But that has been described on the forums before. The only thing I've seen wrong with lapping in person is about 8 years ago, someone sold me a "refurbished" #5 (not a forum member) and they had really lapped it hard. In those days, a junk #5 could be had for a dollar or two and people were paying $80 for a refinished one (I didn't, but you get the point). The plane I got had been lapped until there was no cosmetic imperfection anywhere on the sides or bottom, and it was overdone. In terms of usefulness, it was easily as useful as any other #5, but it was more convex on the bottom because the lapping was overdone.

For the rest of us, where you're going for performance or correction of a problem, it's do as little as you have to and then stop.

To summarize what I did:
* go to a glass shop, tell them that you need a glass shelf for a cabinet (that's where precut glass - as in not expensive custom glass - will be available in long thick runs), if they don't have something, call a different glass shop
* order something like mirka gold rolls - I like 80 and 220. Going above 80 when flattening a plane is just cosmetic, though.
* find somewhere flat to put the glass (for me, that's the bench). The glass will flex over long spans, but not short ones, so if your bench is relatively flat, it will do just fine
* Figure out where the plane is off. If the plane is concave, just work the ends with hand pressure in the spots that need to be removed, stopping to check fairly often. If the plane has minor twist or is fairly close to flat already, but it's a jointer or a smoother, then assemble the thing and push the plane on the lap as if you're using it, brushing or vacuuming the dust off as you go - every 20 to 50 strokes or whatever, whenever the paper looks to be loading
* if you have a straight edge, check the bottom of the plane. AS soon as it looks close to being in plane and the mouth is coplanar or close to the rest of everything else, stop, vacuum or brush the bottom of the plane off and try it. Lap as little as you can to get a good result - the less the better.

That's the extent of the process. You only do it once, and the process will always create a plane that's biased a little bit convex - exactly what a skilled user will want.

In my opinion, lapping and grinding shouldn't be done for cosmetics - you just quickly remove any layer of protective oxidation that's on a plane and guarantee if you use a plane like that and don't just wax it and set it on a shelf, it's going to rust on the cheeks - and it won't look nice like patina.

There is one place where grinding does make sense - squaring a plane. One only needs one plane like that, and and you may chance across a vintage plane that's already well within acceptable squareness to do work on a shoot board.

Well, there's one other place, I guess. If it just pleases someone immensely to have a plane that's ground all over, then do what pleases you.