Flatten plane sole - assembled or apart?

[Daniel Rode]

I'm going to check and flatten the sole on my block and #4 tonight then move on to sharpening the irons. I'll be using 60/100/150/220, etc sandpaper on my jointer bed to do the work.

The big question is do I flatten with the plane disassembled or assembled with the iron retracted? I've seen and read both methods and I don't know which is correct. It would seem to make sense to flatten the sole with the iron and cap in place because that's how it's used and it needs to be flat in use not taken apart bu I don't really know.

Is there a consensus on which way or does it even matter?

-Dan

[Bill White]

Retract the iron, flatten sole with the normal tension as if the plane was "working". That's what I've done. Others may differ, but it is just my method.

[David Weaver]

It doesn't make much difference if the plane is a decent plane. I always do it with the whole thing together, it's easier to flatten a plane by hand if you have the maximum number of things to grab on and you'll get a better job out of it if you flatten it taking strokes in one direction as if you are planing, and keep your grip firm (so as not to allow the plane to rock).

But if the plane is out of flat enough to need lapping (twist or concavity especially), really anything you do will probably improve it. Less is more when you're lapping, too. Lap it until it's flat, not until it's pretty.

[Dave Parkis]

I flatten them assembled with the iron retracted.

[Christian Castillo]

I flatten them assembled with the iron retracted.

+1, I agree with all the posters above.

[Jessica Pierce-LaRose]

I agree with what others have said - it might be different if you were trying to fixture it into a machine surface grinder thing like Tablesaw Tom does, but like Dave says, I don't there's much difference if the plane is decent, so I opt for assembled because it gives you something to hold. Dave's tips about the method used (always go in one direction, etc.) are also helpful.

I'd also add that I always start with something in the finer grits - while I doubt the coarse scratches from something like 60 grit really make a huge difference during use, it seems a shame to start with something coarse, make a bunch of scratches, and realize that the plane is actually flat enough for use (or doesn't need a whole lot of coarse removal) only after you start with something very aggressive. A few strokes should give you an idea of the current state of the thing.

[Jim Matthews]

Not to be flip, but are you sure this is necessary?

Have you put a straightedge on the sole (with the works assembled) and shone a light under it?
If you can't see any light, it's ready to go.

[Daniel Rode]

I spent 4 hours lapping last night. I did my block plane and #4 at the same time. I used a sharpie marker on the sole and a piece of 320 grit sandpaper mounted to glass so I could gauge how flat they were to start. I was hoping one or both might be close. I was wrong. Both were far from flat. Since they are both Stanley "contractor" model planes, I'm not surprised. I switched to 60 grit paper and went to work lapping. The vast majority of my time was spent on the 60 grit. 3 hours and 4 1/2 sheets later, I was confident that both soles were flat everywhere it mattered. I also worked the sides. I tried to get them flat and perpendicular to the sole. They are close but I may revisit this later if it's important.

After I felt I was done with the 60, I ran the plane at and angle in each direction to create diagonal scratches. I switched to 100 grit. The cross scratches are a visual guide that let me know when I had removed all the 60 grit marks. Then I made some 100 grit diagonals and dropped to 150 and then 220. That's where they sit now. I'm not sure if I need to go finer that 220. The soles are not polished but they are very smooth. I have paper up to 2000, so I *can* go further.

Is there any advantage to getting them smoother than 220?

Tonight, Once I'm sure I'm done with the soles, I'm going to work on the sharpening the irons. It may not be strictly necessary, but I'm going to check and re-flatten the backs, re-grind the primary bevel and then sharpen and hone using a micro bevel. I've heard about setting a camber to the iron on the #4. I'm not going to do this right now. I don't really understand what it does or how to correctly add the camber.

After that, if I've done my work well, I should have 2 tuned planes that are ready for work. Then I can start working on technique.

[Daniel Rode]

I think it's necessary for a couple of reasons. First, these are inexpensive planes and the factory level of fit and finish is low. Even though I partially flattened them when I bought them, when I checked I discovered they were way off. To work competently, these need far more attention than a higher quality plane. I want them to work well, so I need to prepare them well.

Secondly, I want to build this skill. If I'm going to use hand tools, I need to know how to set them up and maintain them. IMO, this is no different than my table saw, power jointer or a router.

Also, I feel a lot better practicing on a $35 plane than I would on the better planes that I might eventually buy.


Not to be flip, but are you sure this is necessary?

Have you put a straightedge on the sole (with the works assembled) and shone a light under it?
If you can't see any light, it's ready to go.

[george wilson]

As a machinist I know that metal,especially thin cast iron,is easy to bend. Therefore,I'd recommend,like the rest of the responders here,to lap with the plane fully assembled and the iron retracted some,but under normal tension.

Some years ago,I was installing a collet chuck on a large lathe with a D8 size spindle. D8 is pretty massive. I had tightened all of the bolts quite tight. I mean REALLY tight. The collet was running out a few tenths(.0001"'s). That is well within acceptable tolerance. I am a perfectionist though,and wanted it closer. It was remarkable to me that by tightening an already very tight bolt,I was able to get the collet down to that last .0001". And,the steel in the mounting was over 8" in diameter,and over 1" thick!!

How much force do you think,by comparison,it would take to warp a thin,cast iron plane? Not much. That's why I would lap when assembled and all screws under tension,cap iron too.

[David Weaver]

George your comments are why I'd lap a plane together, though the accuracy isn't that important, but more importantly, lap it similar to the way you're going to use it.

And if it's convex and it seems like the toe and the heel are low and aren't getting worked fast enough, literally put your hands on the part of the plane you want to remove metal from, the metal will get worked wherever your hand pressure is.

[Charlie Stanford]

I think it's necessary for a couple of reasons. First, these are inexpensive planes and the factory level of fit and finish is low. Even though I partially flattened them when I bought them, when I checked I discovered they were way off. To work competently, these need far more attention than a higher quality plane. I want them to work well, so I need to prepare them well.

Secondly, I want to build this skill. If I'm going to use hand tools, I need to know how to set them up and maintain them. IMO, this is no different than my table saw, power jointer or a router.

Also, I feel a lot better practicing on a $35 plane than I would on the better planes that I might eventually buy.

You'll never get there unless you spot sand, or better yet scrape, the high parts. Once you get things fairly well straightened out then it's time to lap the entire sole in order to *essentially* blend everything in. Learning to scrape is building a skill you could potentially use elsewhere, rubbing the whole thing around on sandpaper while it teeter-totters between different high spots generally making things worse isn't really building a useful skill. You've already lost four hours and in this amount of time you should have been able to almost achieve Lie-Nielsen or Lee Valley flatness on one plane at least, maybe one plus about halfway through another. It's like planing a board - you hit high spots to get the thing closer to a point of equality and then you start making full strokes, the corollary in sole truing being lapping.

This is a reasonably decent place to start:

http://www.amgron.clara.net/plane%20sole%20scrape%20105.html

By the end of all of this you'll probably wish you'd simply bought wood-bodied planes that take about ten minutes for a sole true up.

[Dave Parkis]

Daniel, I do not go beyond 220 grit when flattening. IMO, that doesn't add any benefit other than make it prettier.

[Daniel Rode]

Ummm. I did get there. The soles of both planes are flat. I'll check out the link but barring future damage, I'm done with soles of these 2 planes for good.


You'll never get there unless you spot sand, or better yet scrape, the high parts. Once you get things fairly well straightened out then it's time to lap the entire sole in order to *essentially* blend everything in. Learning to scrape is building a skill you could potentially use elsewhere, rubbing the whole thing around on sandpaper while it teeter-totters between different high spots generally making things worse isn't really building a useful skill. You've already lost four hours and in this amount of time you should have been able to almost achieve Lie-Nielsen or Lee Valley flatness on one plane at least, maybe one plus about halfway through another. It's like planing a board - you hit high spots to get the thing closer to a point of equality and then you start making full strokes, the corollary in sole truing being lapping.

This is a reasonably decent place to start:

http://www.amgron.clara.net/plane%20sole%20scrape%20105.html

By the end of all of this you'll probably wish you'd simply bought wood-bodied planes that take about ten minutes for a sole true up.

[Charlie Stanford]

Ummm. I did get there. The soles of both planes are flat. I'll check out the link but barring future damage, I'm done with soles of these 2 planes for good.

Can't argue with success. What are you using to check flatness?

[Chris Griggs]

You'll never get there unless you spot sand, or better yet scrape, the high parts. Once you get things fairly well straightened out then it's time to lap the entire sole in order to *essentially* blend everything in. Learning to scrape is building a skill you could potentially use elsewhere, rubbing the whole thing around on sandpaper while it teeter-totters between different high spots generally making things worse isn't really building a useful skill. You've already lost four hours and in this amount of time you should have been able to almost achieve Lie-Nielsen or Lee Valley flatness on one plane at least, maybe one plus about halfway through another. It's like planing a board - you hit high spots to get the thing closer to a point of equality and then you start making full strokes, the corollary in sole truing being lapping.

This is a reasonably decent place to start:

http://www.amgron.clara.net/plane%20sole%20scrape%20105.html

By the end of all of this you'll probably wish you'd simply bought wood-bodied planes that take about ten minutes for a sole true up.

This is great info Charles. I have a big old Sargent 424 I never got as flat as I would have liked and have been looking for something better than lapping and or spot sanding. Thanks!

[David Weaver]

It's easier to use a 2x3 inch or so flat wooden block with very coarse sandpaper, but using the same marking setup that you'd use if you were doing scraping. Scraping will leave a lot of people who don't do it all the time breaking out bits around the edges of their planes and especially around the mouths.

The couple of jointers that I flattened I first blued the bottom with dykem, then ran them over the lap to find the high spots and put the plane upside down in the bench vise to spot sand. Blue again and repeat. It takes about 20 minutes or a half our to do a jointer this way, you can remove metal very fast with a 2x3 block of sandpaper with 80 grit heavy cloth aluminum oxide sandpaper on it, and the small contact area means the paper will work well until it's totally worn out. lapping a plane entirely on a long flat surface is slow going and as soon as the paper loses a little bit of tooth, the contact area is too large and it stops cutting effectively.

That assumes that you have a long and flat lap to do it, though - dead flat.

What took me 5 hours on the first jointer I ever lapped took about half an hour with this method, though, and the plane is probably flatter, even if it's not as pretty. Well, someone else has the plane now. The only thing undesirable about it is with that much dykem drying on a large surface like a jointer bottom, you need to have fresh air or some air circulation.

I had less luck with scraping in terms of speed.

[Charlie Stanford]

This is great info Charles. I have a big old Sargent 424 I never got as flat as I would have liked and have been looking for something better than lapping and or spot sanding. Thanks!

Good luck Chris. As David cautions, be careful at the arrises. Jeff Gorman's site is pretty much a must read, if you haven't visited there before.

[Chris Griggs]

Thanks guys. Mostly I just need to get off my butt and do it. I get by fine without having it dead flat (and w/o using it at all), but its such a lovely old plane I really want to get it performing ideal at some point...I'll "get round tuit" eventually by one method or the other.

Great site Charlie. I feel like I've run across it before but never really read though it. Just took a look at it. Lots of great stuff. Looks like a fantastic resource!