# Lapping a hand plane .. ugh!!!



## SeaQuest (Jun 2, 2008)

I've got a Stanley #5 that a friend gave to me. I've been woodworking for many years but am just starting to explore hand tools. I want to get this Stanley into good shape and I know that one of the main tasks is lapping the base. I've been working on that and noticed a bit of a low spot (a bit larger than a quarter) at the heel of the plane. When I look across the base of the plane (looking at it from the toe) I can also see this same low spot because I see a faint sliver of light under the straight edge along the heel, we're talking less than 1,000th.

My question, how critical if this? It's barely a sliver but I've been working for two days with 150 grit sandpaper on glass to try and level this out, unsuccessfully. The area around the toe and mouth of the plane is flat. Everything I've read says the sole needs to be entirely dead flat but how realistic is that, especially with an old plane?

My arms are killing me so I'm ready to toss this plane if I need to get rid of that spot. Alternatively maybe there is an easier way of lapping because this is really tough and exhausting work for very little progress. I'm don't think I would ever want to do it again! Any advice?


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## AaronK (Nov 30, 2008)

one question is, how much of an area - particularly how long is the area - is that low spot? the thing about the heel is, if it's far enough back it doesn't matter, since most of the load will be carried by the front/middle. probably the worst thing that can happen is a convex spot right in the middle near the mouth. and the toe should be good too. but the heel? if it's far enough back, it's basically irrelevant.

So I'm of the opinion that it doesn't really matter - when handplaning both the wood piece and metal plane body flex a bit. 0.001" is not a whole lot and I wouldn't bother. You'll get different opinions though. the best thing to do is see for yourself:

sharpen up that blade really well (enough to shave hairs off your arm without it hurting ), tune up the rest of the plane, and give it a shot. if you've got other experience in woodworking you'll be able to tell soon enough whether or not it gives you a flat surface.


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## Viktor (Jan 15, 2009)

It will not make any difference. 0.001" is beyond anything (precision wise) that can be made out of wood.


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## ChrisForthofer (Jan 1, 2010)

Speaking as a machinist (been in the trade for 13 years now) you have a pretty flat plane there. Not granite plate flat, but like Viktor said its more than anything you will ever need for wood. Sounds like the plane has a sink in it from the original casting. It could be surface ground at a machine shop with a good surface grinder but it wouldnt be worth your time or money. I would speculate that its been like that from the day its sold, it would be very difficult to wear a localized spot like that even with years of use. Good luck with your new tool.

Chris.


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## AuroraWoodworks (Nov 6, 2009)

I just discovered this trick for lapping a sole last week. I use a piece of scrap granite from a countertop fabricator as my flat surface. I was using sheets of sandpaper with spray adhesive, but they didn't last very long. Then I grabbed a broken 50 grit belt from my belt sander. It's much more durable than regular sandpaper.


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## canadianchips (Mar 12, 2010)

I would not be concerned with 1/1000. You are probably going to use the #5 to joint or rough down you lumber to as flat as you can. You will then use a number 3 or 4 to smooth the final job anyway. Some of the old planes came from factory this way and the old craftsman were still able to do excellent work. It is good to get the rust off and have it nice and shiny as possible ! 
If you are unhappy with it--send it across Canada. I have a home for thing like that. LOL


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## swirt (Apr 6, 2010)

Agreed with all said already. Call it done. 1/1000th of an inch…. wood breathes more than that from one day to the next. Definitely not critical on a Jack plane. In general I think articles on the internet has somehow made people crazy about sole lapping.


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## paratrooper34 (Apr 27, 2010)

Good advice from the previous posters….this is a jack plane, used for reducing stock relatively quick. It doesn't need to be any more flat than you already have it. Give the blade a good sharpening with a slight camber and put it to work.

Good Luck!


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## Deltarich (Nov 6, 2008)

I have actually had pretty good success with Lee Valley lapping compound. I know a lot of people swear by the sandpaper method and I use that too for the blades but prefer the lapping compound to get the sole flat.


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## davcefai (Feb 6, 2009)

Apart from all the above good advice, 150 grit is way too fine to start with.

I start with 60 grit, stay with it as long as necessary to get the sole smooth. After that I work up through the grits, each grade removing the scratches left by the previous one..

Call it 2 hrs on 60 grit and another 2 to work up to 400 - at which point you're approaching mirror finish.


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## AaronK (Nov 30, 2008)

also remember that there's no need to get a mirror finish on the body of the plane. corrugated soles were supposedly made for exactly that reason.


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## davcefai (Feb 6, 2009)

"no need to get a mirror finish on the body of the plane"

True enough, but it does not take much extra effort to go to 400 grit and then you get that sense of satisfaction


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## PurpLev (May 30, 2008)

it's a #5. as long as the mouth area, front of sole, and back of sole are lined up, I would not worry about any low spots - they are more than likely to be there, and will make no difference on operation or performance of the plane.

Enjoy your plane - it's more than flat enough for use.


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## DDDamian (Sep 14, 2010)

Machinist here too - if you really want to hone it sharp use a fine lapping compound (Clover brand is the most common for metal work) on a piece of glass. If you look at the grit sizes of sandpaper they're way in excess of the 0.001" you've mentioned. Hell, they finish straight razors by stropping them on hard leather! If the compound is out of the question mix Ajax or another abrasive cleaner with vaseline and go at it on a piece of glass.

That said, 0.001 is small on metal, on wood it is immaterial…..


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## Nomad62 (Apr 20, 2010)

Whether or not it's "necessary" will be the decision of a tool restorer, a woodworker, a whatever…it's all up to the one owning it. Maybe it won't work better if dead flat, but maybe it will "feel" better to the owner knowing it is anyway. Davcefai hit the nail on the head, you need to start rough and go smoother. Try a file. Try a belt sander. Get it flat then go for the smoothing.


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## Gofor (Jan 12, 2008)

If the area under the tote is flat with the rest, the plane should do you okay. But, longer flat on the heel is better as you rock pressure back to it, and makes the difference between a #5 and a #4, especially on edges, so I would keep going with the little difference you state. That said, I have had best luck with carborundum cloth backed abrasive glued to a flat surface (used dry, the graphite in the ductile iron provides all the lubricant you need). I start with 60 - 80 grit, and work down to finish up with 180 wet-dry paper. I do use liquid (water works fine but will rust up quickly, diesel fuel/kerosene works very well but is flammable/smelly, WD-40 works ok but cuts slower) with the wet/dry papers to minimize clogging.

I used to go on down to a mirror finish, and admit it looks nicer. However, I have not seen any difference in the plane's performance.

Realize that a lot of old planes were used/abused planing door edges, etc, and may not be worth the trouble to completely flatten all the way to the end, especially if it thins the sole so much that it flexes more. If you thin the sole too much, you just made a really attractive wall hanger. If this is the case with this plane, just use it with the realization that it may be more of a "#4 3/4" than a true "#5", the difference which is minimal.

Go


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## Dark_Lightning (Nov 20, 2009)

OK, another machining type says- if you move your metal in a figure 8, it will tend to even out the sole better. It is possible that the way you are holding it has brought the side opposite the divot down quite a bit, without touching that low spot! That's just an artifact of the human hand, and budding machinists learn it the hard way, just like newbies with a belt sander get all kinds on unevenness when sanding a piece, since they don't realize how fast the material is coming off. Check to see if your blade still lines up with the mouth square when it is straight as viewed from the top of the plane. You may have ground the opposite corner way down.


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## JSZ (Jan 5, 2010)

Because of the geometry of a hand plane, only three areas on the sole need to be in the same plane: across the width of the sole at the toe, directly in front of the mouth, and at the heel. Hollows in between these areas do not affect the performance of the tool. Japanese planes are tuned up precisely this way - in fact there is a special hand plane used to create these hollows. Imagine the back of a Japanese chisel.

Because the tool is generally held around 90 degrees ( or sometimes skewed a bit to create more of a slicing cut) the long edges of the sole don't play much of a role here. Think about planing the edge of a board - the long edges of the sole aren't involved in that operation at all.

On the other hand, a high spot in the areas between the toe and mouth, or between the mouth and heel need attention, because the plane will rock up and down on them.

As for a flat reference surface, it is hard to beat a granite test plate. They are not all that expensive if you purchase what is known as "toolroom grade" (we would call them "seconds" because there is usually some visual defect) and they are all certified flat. I know glass is supposed to be "flat" - but how flat? The test plate answers that question for you.


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