Ever build an end grain table top?

[Bob Jones]

I have access to a local, old, oak log. The base diameter is about 6 feet. I have been wanting to build a "round", natural edged table that is made from a slice of a tree. This way, when you look at the table-top you will be able to count the growth rings. Has anyone ever tried this?

I do most of my surfacing with hand planes from rough sawn wood. I have not planed any end grain, really. I think the project would look great, but since I have never this done before I am guessing there is a reason... I would love to hear from anyone who has ever seen this done, or done it themselves.

FYI - I did extensive searches and found nothing...

[Richard M. Wolfe]

When you take a slice off a log like you are talking about you will find it is next to impossible to dry without cracking. And oak is one of the worst about doing that. You might try banding it and cinching it up as it dries - I have no experience at that. Also, as open pored as oak is it would really take a lot of finish to properly seal the wood.

[John Michaels]

From what someone told me, the pith in the very middle of the slab is what tends to make the wood crack. Maybe cutting a whole in the center to relieve the pressure would help. Take this with a grain a salt because I have no first hand knowledge if this is true or not. Maybe others here know more about this. Good luck.

[Ronald Kellison]

The wood will develop cracks on a line from the center out to the edge. You may be able to control the larger cracks by installing butterfly joints but I suspect this will be more trouble than it's worth simply because it may take 10 years for a crack to appear. It's entirely possible that a crack can be large enough to cause your table to split apart at some point. The only way to deal with this would be to incorporate some type of strong banding (old wrought iron?) around the entire rim of the table.

You don't say whether it's red oak or white oak. If it's red oak any finish you put on it will wick through to the bottom of the table. It may take several coats before the pores are sufficiently sealed to stop this from happening. You will have a large mess to clean up on the underside. If it's white oak the pores should either be sealed already by the tyloses present in white oak or small enough that they will seal quickly with the first coat or two of finish. It will still crack on you.

Planing the end grain could easily turn into a career! I would think the only viable option would be to sand it with a belt sander, preferably one mounted on a sanding platform designed for that particular sander. You may also be able to level the surface with a router/1" straight or dishcutting bit mounted on a jig. This type of jig has been written up in most popular woodworking magazines and may also have been discussed on this (or other) forums.

Bottom line: If you're seriously considering this you are a braver man than I am!

Ron

[jason lambert]

well from wood turning we seal the end gran with a sealer like wax substance that gets painted on this prevents the cracking by letting the wood dry slowly nad evenly. Most cracks are caused by the wood drying to fast and unevenly. Also there are other tequinequs like soaking in 1/2 amber dish deturgant for days to help the cracking. If it was me I would seal the log with a sealer and let it sit a long time to dry out, you can't sand/seal wet wood anyhow. Then go back to it in a year or two or three depending on the thickness and see what happened. You just can't do this project with wet wood, you will have warping to when it drys so slice it thick enought to plain down after it drys. Oak is tuff though it is one of the harder woods to surface.

[Chris Friesen]

I have access to a local, old, oak log. The base diameter is about 6 feet. I have been wanting to build a "round", natural edged table that is made from a slice of a tree. This way, when you look at the table-top you will be able to count the growth rings. Has anyone ever tried this?

I think it would look really cool.

As others have said, it would be hard to keep it from cracking. You might try soaking it with PEG to stabilize it, or maybe you could purposefully make some radial cuts to try to control where the cracking occurs.

On a totally different issue, you'll probably have to support it from underneath somehow. Vertical grain isn't nearly as strong as the same thickness of horizontal grain because (vastly simplified) you're relying on the bonds between the wood fibers to carry the load rather than the fibers themselves.

[David Keller NC]

Bob - Living in Raleigh, NC (the nickname is "city of the oaks"), going through a few hurricanes, and sawing a lot of my wood with a chainsaw lumber mill has taught me a few things about what you'd like to do.

The reason they crack is that the wood shrinks tangentially along the grain, and the outside is larger than the inside, so there's differential force applied across the grain as the moisture leaves the wood.

So, the slice off of the end of the tree will crack, no matter how you dry it (slow, fast, PEG impregnated, whatever). The best way to deal with this is to make your own crack with a cut from the bark to the center. As the slice dries, this cut will grow larger into a pie-shape. Once the slice has dried sufficiently, you can cut a similar pie-shaped piece from another slice and fill the gap by butterflying it.

The other issue if it's red oak is that it has very little resistance to shearing with the grain, which will make the table top very weak - someone leaning against it could easily split it. So you're going to need to back up the bottom with something that will strengthen it - like plywood or perhaps a glued-up solid wood panel.

Good Luck - should make an impressive table if you pull it off.

[Aaron Beaver]

Me personally, I wouldn't care if it cracked. I would like the 'natural' look of the table if it was for myself. Some may not like that type of look and want a more finished look.

[Joe Jensen]

Wood shrinks mainly tangentially and little radially. This is why quartersawn wood is very stable dimensionally over humidity changes and why it warps little. Flatsawn on the other hand moves a ton, and it warps with changes in humidity.

A slice off a tree with develop cracks from the center because the wood will shrink a lot tangentially as it drys. The circumference at the outside is many times longer than at the inside, so the outside will shrink a lot compared to the inside. In HR high school shop we built stools out of slices from a walnut tree and mine developed one crack. My slice was about 18" in Dia and the crack was about 1/2" at the outside. I filled it with epoxy and it's still stable 30 years later.

[Joe Jensen]

Wood shrinks mainly tangentially and little radially. This is why quartersawn wood is very stable dimensionally over humidity changes and why it warps little. Flatsawn on the other hand moves a ton, and it warps with changes in humidity.

A slice off a tree with develop cracks from the center because the wood will shrink a lot tangentially as it drys. The circumference at the outside is many times longer than at the inside, so the outside will shrink a lot compared to the inside. In HR high school shop we built stools out of slices from a walnut tree and mine developed one crack. My slice was about 18" in Dia and the crack was about 1/2" at the outside. I filled it with epoxy and it's still stable 30 years later.

"Wood averages 7.95% tangential shrinkage, with some species as high as 12.7% in overcup oak" per "Understanding Wood" by Hoadley. So, say the cutoff is 36" in diameter. The circumference will be the diameter times pi (3.14), circumference is 113". The circumference in the middle of the slice is negligable as the the diameter there is small. An 8% shrinkage means that the wood at the circumference will shrink 10" or so, or 10 one inch cracks.

[Doug Donnell]

I have zero experience with oak or large tables, so take this with a grain of salt.

Radial checking is going to be a bear to deal with. As a forester and timberland investment manager, I have tried several methods of cutting "cookies" to demostrate to clients the relative growth rates (as shown by growth rings) of different management strategies. It is very difficult to control the radial checks. I have not done it, but others have had some success by immediately sealing the cookie with epoxy resin over the entire piece. This fixes the moisture content, at least till the epoxy fails, but might be difficult to get a furniture quality finish.

You might try a different table design that incorporates a straight edge (like a console or hall table), that might relieve the radial stress. You might also saw the round slice straight down the middle, hope that relieves the radial stresses, dry the slices over several years with the end grain sealed, then rejoin the two pieces after jointing the edges (be safe!).

What does everyone think?

[Chris Padilla]

Mr. Keller from NC has my vote. It will crack...don't fight it...just be prepared for it.

FYI, I think it would be a spectacular table. Cut two "cookies" (love that term!) and when eveyrthing is all done cracking, merge the two pieces into a seamless, continuous top.

Do you have any pics of the tree?

Another thought: Has anyone ever done end-grain veneer work?

[Michael Schwartz]

I too would agree to let it be, and just assume the fact it is going to crack from the beginning.

Project like this would be a good opportunity for a butterfly inlay.

If you want to have a flat surface with no cracks, I would fill the cracks with a clear epoxy. Another option would be to have a glass top cut for the table.

[John Schreiber]

It will crack and short of cutting it into many pie shapes, you won't be able to control where. A natural table can still look very nice with cracks in it though. I'd probably let it dry out for a year, sand it flat and make a table where the tree trunk you can see is not really structural, but is "floating" on top of the structure. I'd also figure that it will crack further and will require more maintenance in the future.

But it could still look very nice and be completely worth while.

PS I saw a really cool router jig for flattening a surface like that. It was basically a frame hung off door hinges which could swing back and forth with the router moving out a bit on the frame after each swing.

[Bob Jones]

Thanks for all the advise! I got a better responce than i expected.

I inspected the log today - not as good as the home owner said. I will have to keep looking for the right log. It should not be a problem around Memphis - lots of big old oaks. This will definately be a long term project, if I take it on. My leaning is to go natural and let it crack naturally as it dries in the woodpile. I do not like the feel of the epoxy surfaces, I think I would prefer the feel of cracks (rustic over plastic!).

Thanks again, and I would love more input!