Help on work bench table flatness

[tiralie]

I cut the material with my TS75 and I hope that it is cutting square.

Ya, I have used the "hope" and alternatively the "assumption" method as well. In my case I am just too lazy or too much in a hurry to check. It's 50/50 at best. I have had to redo several glue ups because what I thought was square wasn't/
Always good to be sure. Use a good carpenters or engineers square and check and then clean up the edge with a plane.
While you are getting you LN plane(s), check out the Starret engineers square...
Tim

 

[semenza]

You could try flattening it with a sled and a router bit. Make sure you finish the top and bottom with the same amounts of finish .

Ripping it apart with a tracksaw and starting over would also work but you need to make sure the tracksaw blade is at 90 degrees or flip the boards when regluing (careful with the grain direction)

Handplanes work great you can't go wrong with LN but keep in mind sharpening and technique is equally important so if you buy planes, buy stones.

Considering this is to be a workbench perhaps consider the hand planes and work on your jointing and sharpening techniques while flattening your bench

Dan Clermont

After ripping it apart split the kerf between two mating boards and recut. Guaranteed match.

Seth

 

[Sparktrician]

If you are not concerned about it warping a second time (after you level it) then I would suggest using a router sled jig to flatten the top. Simple and easy approach, there are lots of examples on the web including:

http://www.dans-hobbies.com/2008/06/28/simple-router-sled/

RMW

There was an article in Fine Woodworking (#222, November/December 2011) on Nick Offerman's version of a router sled.  Pretty slick.  I'm making a version of this using phenolic-covered Baltic birch for the sled itself.  The dust extraction of the OF 2200 should make this a very efficient assembly. 

 

[Runhard]

Here is a close up of the area that looked like it was checked and it really isn't that bad. I also included more pictures.

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[mouppe]

OK, I have had another think about this. 90% of your work is going to be on the front half of the bench so you can focus on flattening this and forget the remainder for now.

Looking at the second photo you just posted, it is clear that your main problem is that the top of your rear jaw is not level with your first board. The simple solution is to plane the front edge of the rear jaw down until you have a level surface- at least for the first 12 inches or so of the benchtop. Afterwards, the face of your rear jaw may not be square to the top but rarely does this matter and there are always workarounds.

Does this make sense?

Once a year or so, you'll probably maintain your bench by planing it, removing glue drips etc. so over time, you'll improve the total flatness of your top anyway. My bench is far flatter now than when I first made it several years ago.

 

[Michael Kellough]

The best practice in joining flatsawn boards is to alternate the bark side, exactly as you have done here.

My previous post was mostly concerned with subsequent seasonal movement. Since these boards are flatsawn I think they're are too wide for long term stability. If everything else was perfect I'd rip the middle third out of each of those boards, invert it and glue it back in.

But, as others have pointed out, the biggest problem here is with the jointing. The glued up joint is only about 89.5* per half so the left side drops about a degree below the center board. So, you need to re-rip at the joints as well.

After you re-rip, clamp up the boards dry and check with the straight edge (assuming the individual boards are still dead flat). If you still get big gaps under the straight edge as in this photo then you should re-adjust the screws that set the 90* (or 0*) angle.

A simple alternative to adjusting the screws has already been suggested, invert alternate boards and the two off-angles become complementary. To try to clarify, if you consider the three horizontal boards in this photo, presumably all with edges at about 89.5*, and simply invert the middle board in that assembly, then the drop on either side of the middle would be eliminated.

(Instead of 89.5 + 89.5 = 179, by simply inverting one board [from the orientation it was at when ripped] you get the equivalent of 89.5 + 90.5 = 180)

The steps I'd take,

1. Re-adjust the stop screws on the saw base.
2. Rip the boards apart
3. Re-rip the edges of the left and right boards (keeping the bark-sides up)
4. Invert the middle board and re-rip it's edges
5. Turn the middle board back to bark-side down and make two rips a third of the way in from each edge. Make sure to support the guide rail with another equal thickness board.
6. Invert the left and right boards and rip the middle third out as above.
7. Re-assemble all the pieces as in the original configuration and then invert the three middle pieces
8. Clamp it up and check flatness. Unless there is a problem with the straightness of the pieces you should be able to get the surface dead flat since all the adjacent bevels are complimentary. The surface should stay flat for a long time because the pieces are not so wide and the bark side alternates every piece.

 

[Michael Kellough]

Don't try to constrain the seasonal movement of the top with stretchers and tenons like this.

You should turn the Dominos 90*. You can use a tight mortise in the slab but the tenon in the stretcher needs to be long to allow for the movement of the slab. To keep the stretcher tight to the bottom of the slab you can put a small Domino into the side of the big Domino kinda like a drawbored tenon.

In this drawing substitute the slab for the rail. Put a tight mortise for your largest Domino into the slab (minimum mortise). Put a long mortise into the edge of the stretcher (stile in this drawing). Insert the Domino into the middle of the long mortise and wedge and clamp it so you can can bore a small mortise for a small Domino through the side of the stretcher and into the large Domino. Then remove the large Domino and bore a long mortise into the side of the stretcher centered on the mortise you just bored.

Do that on both ends of the stretchers. Apply wax around the long mortises of the stretcher, insert the large Dominos, insert the small Dominos into the sides of the large, apply glue to the ends of the large Dominoes, put glue into the mortises in the slab, get the ends of the large Dominos lined up with the mortises and hammer the stretchers tight onto the slab.

The drawing shows a joint that will be tight in all directions but you'll use a small Domino in place of the dowels and a long mortise in place of the drilled holes so you'll allow movement of the large Domino/slab in the direction the slab wants to move.

 

[semenza]

Oh the dominos run with the grain on the those bottom cross pieces. That is definitely going to prevent wood movement. I was picturing them  running perpendicular to the grain in longer (wide) slots to allow movement.  Regardless of the construction method you end up choosing that needs to be changed.

Typing at same time as MK.

Seth

 

[Runhard]

I just ordered a Lie-Nielsen No.4 Bronze Smoothing Plane and a Lie-Nielsen No.62 Low Angle Jack Plane. I already have the No. 60 1/2 Low Angle Adjustable Mouth Block Plane. I have DMT Diamond plates for sharpening: 325, 600, 1200, and 8000 along with a leather strop and honing compound. I haven't used my hand tools more than 30min and this will give me some practice.

Thanks,

Daniel

 

[rustym]

Daniel,
Since you ordered a #62 plane, after you get it when you cut your boards apart lay them on something flat and decide which pairs will be together.  Fold them to themselves from the bottom (like if you were resawing them on a bandsaw and you fold them open for a bookmatch), the top edges that are together get them as close as possible even with each other and put them in a vise and plane them with the 62.  This will make both edges flat at the same time and even is they are not perfectly square they will offset each other when folded back together. Clear as mud :.  May be a little tuff on something that thick to plane them together but you can do it.  It's just like taking two books and laying them on a table with the spines together fronts up, picking them up still with the spines together and folding them down so there backs come together.  The resulting two spines will be ready to plane flat.

Rusty

 

[jeep jake]

Just get yourself a Lie-Nielsen No 62 to flatten the top of your bench and that should work fine. That is what I used to flatten the top of my Joinery bench with the Moxon Hardware installed. I am no expert when it comes to hand planing but the No. 62 will work out nicely on this size bench.

James

Thats a killer little bench

 

[Jmaichel]

Just get yourself a Lie-Nielsen No 62 to flatten the top of your bench and that should work fine. That is what I used to flatten the top of my Joinery bench with the Moxon Hardware installed. I am no expert when it comes to hand planing but the No. 62 will work out nicely on this size bench.

James

Thats a killer little bench

Thanks Jake!

 

[PierreA]

Hi Ruhard,

To minimize wood movement you should not laminate wood board wider than 4".

Plus when you choose your board try to find the one cut near the center they are mostly quarter saw and are more stable.

http://www.google.ca/imgres?client=safari&sa=X&rls=en&biw=1246&bih=664&tbm=isch&tbnid=89dJ2faGNsR7TM:&imgrefurl=http://www.flickriver.com/photos/goodmoldings/5019335583/&docid=JscWka-RWovETM&imgurl=http://farm5.static.flickr.com/4125/5019335583_ce0a1cc625.jpg&w=500&h=197&ei=eYduUsCnNYjE4AP2tIDwDQ&zoom=1&ved=1t:3588,r:91,s:0,i:361&iact=rc&page=5&tbnh=129&tbnw=328&start=80&ndsp=20&tx=163&ty=60

For now the best is flatten it with the plane you bought.

Pierre

 

[stevep]

Surprised no one has suggested the obvious answer if you want a flat bench top, which is to make it out of mdf. You can buy a lot of mdf for the price of a LN no 4.

 

[mouppe]

The OP is looking for a benchtop that can withstand hand tool use. MDF is useless for that.

 

[Runhard]

I received my planes yesterday! I already had the No. 60 1/2, but I have not used it yet.

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And the rest of my small LN collection.

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I wish that I had not already cut apart the bench. I should have tried to flaten it first with the planes, cut it at the joints, cut each board into 3 sections, flip the middle pieces down, re-glue and clamp, and finaly re-flaten with the planes.
Live and learn [doh]

Daniel

 

[Michael Kellough]

I wish that I had not already cut apart the bench. I should have tried to flaten it first with the planes, cut it at the joints, cut each board into 3 sections, flip the middle pieces down, re-glue and clamp, and finaly re-flaten with the planes.
Live and learn [doh]

Daniel

Beautiful tools but I don't understand your regret. If you had successfully flattened the top with planes then there would be no need to cut it apart.
But, you really should learn to get the joints true with whatever tool first.

 

[Runhard]

I wish that I had not already cut apart the bench. I should have tried to flaten it first with the planes, cut it at the joints, cut each board into 3 sections, flip the middle pieces down, re-glue and clamp, and finaly re-flaten with the planes.
Live and learn [doh]

Daniel

Beautiful tools but I don't understand your regret. If you had successfully flattened the top with planes then there would be no need to cut it apart.
But, you really should learn to get the joints true with whatever tool first.

If I had flattened the top first it would have been easier to cut the bench apart with true 90 edges. I still want to make the bench more stable by cutting the boards into smaller sections and re-gluing them together. I may take this opprtunity to redesign this work bench.

 

[Michael Kellough]

I get you, I had thought from the photos that the individual boards were flat but the joints weren't exactly 90*.
You're right, it's pretty darn hard to make square edges if the reference surface is irregular.

 

[Runhard]

I get you, I had thought from the photos that the individual boards were flat but the joints weren't exactly 90*.
You're right, it's pretty darn hard to make square edges if the reference surface is irregular.

Actually only one of the joints was slightly off 90*, I know slighlty off can have a big impact on everything else. The main problem is that all 3 boards are now cupped. A big 16" jointer would be nice to have right about now followed by a planner.