# Lapping the sole of a jointer plane



## Smile_n_Nod (Jan 20, 2011)

I have a #7 jointer plane that I've lapped using sandpaper and glass, but am not entirely happy with the results. I think that the coarse grit (60 or 100) sandpaper sheets are so thick that they flex under the weight and pressure of the lapping action that the sole does not get as flat as I would like. Also, I was lapping on a sheet of glass backed by MDF, but I'm not convinced that these were entirely flat, either. Can anyone tell me where I can get a piece of granite, marble, glass, etc. that is flat enough for lapping and that won't break my budget?


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## WayneC (Mar 8, 2007)

Bertha uses granite or marble that is used on window sills. Send him a PM for some info or perhaps he would see this post. Another option is to use the wing of your table saw. How did you determine you needed to lap the plane's sole?


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## WayneC (Mar 8, 2007)

The other option would be to use some Silicon carbide abrasive grit with plastic on the glass. Examples of the grit can be found here…

http://www.leevalley.com/US/wood/page.aspx?p=59752&cat=1,43072


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## new2wood (Aug 10, 2009)

I would check the building materials section of craigslist. I always see granite tiles for sale. Or if there is a big box close by, you can probably buy one tile.


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## davidswoodwrks (Aug 14, 2010)

Or if you have a buddy with a granite top TS lol.


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## CharlieM1958 (Nov 7, 2006)

Look for a place in your area that fabricates granite countertops. They should have some small cutoffs available cheap, if not free.


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## SCOTSMAN (Aug 1, 2008)

lock the sole facing up on a vice, then rub continuously over the sole with a flat sharpening stone normally used for sharpenning chisels. This does a great job with some oil of course of flattening out the sole of any plane I read about this tip from a British woodworking magazine where the guy did up an old plane .I tried it and it does work great try it on an old plane first if you don't trust this method. Alistair


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## HorizontalMike (Jun 3, 2010)

new2wood has it, go to big orange box store and buy a granite tile for $4.50 each. OUCH!

Either that, or start hanging out at the cemetery when you need to flatten your #7…


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## DMIHOMECENTER (Mar 5, 2011)

Oh, no… go to a home center and get a "sample" ;=) then never return it. Happens to us all the time. :=(

LMAO @ Horizontalmike re: cemetary… visualizing seeing 3M spray adhesive (yellow) spatter on grave stones with strange rectangle shape ripped from the middle.

Just make sure you don't use the lettered side of the monument.


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## Smile_n_Nod (Jan 20, 2011)

How big are these granite tiles? My #7 jointer is 22" long. Should the flattening surface be at least 30" long?


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## Smile_n_Nod (Jan 20, 2011)

WayneC, I used a drafting square for a straight edge and a thickness gauge to measure the plane's flatness. The middle of the plane is flat to within 0.003", but the last few inches on each end deviate by about 0.007". Is that flat enough?


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## WayneC (Mar 8, 2007)

I would think that is more than flat enough… Another way to check it is on the wing of a tablesaw or bed of a jointer.


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## croessler (Jun 22, 2007)

I used Silicon Carbide Paper adhered to 1/4" plate glass to lap my #8


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## Smile_n_Nod (Jan 20, 2011)

WayneC, I have a Ridgid 4510 portable table saw, so the top is not as flat as a slab of machined iron. And my only jointer is the plane.  Good ideas, but I'm still lacking in the power tools department.


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## WayneC (Mar 8, 2007)

Lol. You might not even need power tools. Have you read the Anarchist's tool chest?

http://www.lostartpress.com/product/a1aeb796-1199-45c3-b9ca-99acd1d22b1a.aspx


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## Smile_n_Nod (Jan 20, 2011)

I haven't read it yet, but I'm planning to. I'm having a ball building up my collection of user-tools. I just bought a Millers Falls #2 hand drill today that's in great shape, so that's one more I can cross off my list.


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## WayneC (Mar 8, 2007)

That should a nice drill… I'm hunting for a 6" sweep brace at the moment.


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## bigike (May 25, 2009)

check out grizzly, I think these are the cheapest. if you know where there is a co who sells this stuff see if they can give you a piece for free with no work done on it like polishing
http://www.grizzly.com/products/searchresults.aspx?q=granite&new=1


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## DMIHOMECENTER (Mar 5, 2011)

If you get a piece of granite,it will need to be honed/polished flat. If you were here in town, I'd give you a piece, but shipping would kill that.

Don't use the tile. It's only 3/8 to 1/2 thick. Most are 12×12, anyway.

Contact a granite countertop store, tell them you need a piece of 2 cm or 3 cm thick of 3" or 4" back splash drop 30" long (or so). Tell them you don't care what color the granite is… any will do. Tell them you will pick it up. That should work. It would in this town. Good luck.


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## Dcase (Jul 7, 2010)

I use granite tiles from home depot and they work great. Just buy two of them and put them next to each other to flatten the sole. The crack where the tiles meet wont matter because the sole will just ride over it.

I personally just use a piece of MDF with sand paper attached to flatten the soles of my larger planes. The sole doesn't have to be perfectly flat. As long as the area in front of the mouth is flat the plane will work just fine.


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## Smile_n_Nod (Jan 20, 2011)

Dan, how do you attach the sandpaper to the MDF? Can the MDF be used more than once? Is the MDF flat enough when check with a straightedge?


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## Dcase (Jul 7, 2010)

I use a spray adhesive to attach the paper to the MDF. Any spray adhesive should work. Just spray the back of the paper and apply it to the mdf then press it down and your good to go.

If you clamp a piece of 3/4 MDF down it will be plenty flat enough to lap the sole. You can use it more then once, just peel the old paper off and it should be fine.

When lapping the sole of the plane the general idea is not to have a dead flat sole but rather even out the dips. The area in front of the mouth is most important to be flat. I wouldn't stress about needing perfect flatness. As long as you can even out any larger dips the plane will work fine. The larger the sole the less important it is to have entirely flat.

When I first started tuning up my planes I had it in my head that the soles all needed to be dead flat. I spent hours and hours lapping the soles so that they would flawless and flat. After a dozen planes or so I started spending less time on the soles and rather then going for perfect flat I just lapped them until they were pretty flat and free of any big dips. The planes work just as well as the ones that were perfectly flat.

When flattening the back of a iron or chisel its more important to have dead flat but for plane soles I wouldn't worry about it being perfect. Save some time and money, give the MDF a try and see for yourself. It will work just fine.


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