3 - Router-planed Tree Slice Side Tables With DIY Router Sled

Just the other day….

Several years ago, an old blue cedar tree in my aunt‘s backyard died and needed to be felled.

Most of the wood was decided to be used as firewood but I managed to save two slices to be used for, whatever, if I ever got around to doing something with them….

This is the third in a series of projects of making side/couch tables. I didn‘t plan it that way - it just happened that I had three possible table tops on my hands.

My aim with these is to show how simple it is, and how little you need to spend to get (semi-) decent results. The Labyrinth Table was the most difficult and the first instructable. Then came the Hollow Cherry Tree instructable, which has the tedious legs and now this, which was actually the first build that got done.

The two sections sat around, drying and gathering dust until I finally got a router! Some time before that, I had tried to use an electric hand planer to even the cuts, but had quickly given that idea up as stupid and dangerous. A planer works great when you work along the grain, but when you try to use it against end-grain wood sections the blade can‘t cut as well, so that things tend to block and try flying away if not properly secured. It‘s simply no fun to plane end-grain this way.

Using a router with a planing bit is really simple and gives you a quite smooth surface. Even with a large bit, there is no problem going against the grain, because the removed material is usually a lot less than the mass of the router and the router strong enough so that it cannot block up.

The only problem with the router is that you want to move it back and forth across the work piece.

The solution is to just build a sled for the router to move back and forth and so that you can move it across your tree section one bit at a time.

And you build the whole thing from scrap - as usual - of course!

Before you start planing a tree slice, it makes sense to fill up all the splits and cracks that formed due to drying - I used some clear epoxy.

Once the tree slice is planed, you simply add a couple of legs and you are finished!

Router + Planing Bits

2-Component Clear Epoxy Resin + Mixing Cup

Paint Brush

10 Wood Profiles/Slats, 2 x 5 x 100 cm

2 Aluminum Profiles, 90 deg, 10 x 10 x 80 cm

Electric Sander + Paper, 80 - 240 grit

Clear Varnish

Ikea Stool Kyrre (20€)

When a wooden trunk dries, the wood contracts. Yes, what a great insight! Since wood cross-sections tend to be quite inhomogeneous, the different parts dry differently and you usually end up getting radial splits and cracks. These can be filled with wedges from another slice, or nowadays, it has become quite popular to just use a two-component epoxy resin.

I don‘t have any pictures of the process, because it was done mostly several years ago. I hope you get the idea anyway….

I then decided to use a slow hardening clear colorless resin, because you can pour thicker sections at once, because the slower it sets, the less heat is generated during setting.

Remember: Epoxy is NOT your friend!

Depending on the type of resin you use, there may be poisonous fumes, so always use it in a well ventilated area. It may be not so good for your skin, so avoid contact, wear gloves and goggles.

The resin may seem thick and gooey, but don‘t trust it! It will creep and flow through even the thinnest cracks and holes until you find a big hardened puddle on your floor in the morning and an thinly coated wooden, but otherwise empty bowl, that should have been a solid block by now.

Don‘t use tape to seal cracks, because the glue on tapes usually slowly peals back a bit and may lose contact to the wood, opening cracks again.

What worked really well for me so far was either silicon/acrylic caulk or other glues like UHU, or even wood glue and cardboard to close gaps.

So, seal all visible cracks and holes before pouring the epoxy. I like to apply a layer of epoyx to the wood that I want to fill with a brush first to see if end will leak through somewhere I didn‘t think about. That also seals the leaks that might be there. Where I still was uncertain, I have placed the pieces in a plastic bag, just to be safe - it has helped….

I like to preserve the bark of the tree to make it look more natural, so I painted on some quick setting resin. It also fills all small holes.

When your tree section is completed, it‘s time to plane the surfaces.

Once, when I had access to a fairly large belt sander and otherwise very little time, I used said sander to plane the surface of a 40 cm diameter slice from an old cherry tree. The supervisor and his assistant almost fainted!

That was a really stupid idea. It did work and I broke and hurt nothing. But, that is simply not a sensible thing to do.

What is simple and safe to do to plane a wooden surface, is to use a router with a planing bit on a sled to move across your work piece.

So let‘s build a simple sled from household items - well, from things that are readily available.

The size of your piece of wood is the main criterium on how large your sled setup needs to be. It tells you how wide the sled will need to be on which you will move your router back and forth, as well as how deep your guard-rails will need to extend.

There are many really cool setups on the web, with steel and aluminum bars and bearings and Teflon pads, etc..

As usual, I was a bit rushed and figured that a tolerance of less than 0.001 mm - or so - was a bit over-engineered for my purposes.

Instead, I decided to use simple ca. 2 x 5 cm wooden pine slats, I had left from another project. Straight and smooth, with a span of one meter, the flex in the middle is almost neglible - if you don‘t sit on the sled.

I also had some lengths of 1 x 1 cm Aluminum profiles left from yet another project, that I figured would be perfect for the router to slide on.

The router bits can only be lowered to a certain distance for each router model, to avoid removing the base plate from the router to save space, it is best to place the router as close to the base of the sled as possible. In my case, the thickness of the wood profiles is about the amount the router can be lowered - perfect.

So I simply constructed a rough frame, wide enough to fit the router to slide on the aluminum profiles, attached to the insides of the slats on each side. This way, the router only sits about 1 mm - the thickness of the Aluminum profiles - higher than normal and I don‘t have to take the router apart at all.

The big tree slice had a diameter of around 80 cm, so I decided to make the sled even a bit wider to almost a meter, just in case. This was also dictated by the length of the wooden profiles I had available.

For the side rails on which the sled would move from back to front, I decided to use the same slats, but stacked, to accommodate the height of my work pieces. If I build some tool, I would like it to an Omni-Tool - one size fits all projects….

My big tree slice had almost a thickness of 15 cm, so stacking/bolting initially three slats on top of each other - secured by bolts - would let me thin it down successively, lowering the sled by turning the slats on their sides, or removing them. A simple modular system seemed best to me, and it actually proved very well manageable. Since I don‘t have a „real“ workbench, I decided to simply bolt the lowest profile of each rail directly to the work area with enough space for the work piece plus a bit of extra space for the router bit on each side. With this setup, the 80 x 15 cm piece fits just as the small 30 x 3 cm disks I have - you just have to move the rails together, bolt them down and remove the top slats to fit the thickness.

Always make sure to leave a gap between the work piece and the guard rails for your router bit to avoid catching the rails before and after a cutting pass across the sled.

When you move the sled front/back/front, it‘s nice if it stays oriented perpendicular to the rails. To achieve this, I attached small shelf brackets to the sled. Yes, I could have used a couple of pieces of the Aluminum profiles instead. For my setup, I decided to make the right side rail „permanent“, so correspondingly I added „permanent“ brackets to this side of the sled. When moving the left-side rail, I need to move the left-side brackets on the sled accordingly - easy.

So let‘s start - NOT!

Using a router to plane a piece of wood generates amazing amounts of dust and tiny wood chaff. To prevent this from quickly covering your complete work space and all areas beyond, it is advisable to use a pretty powerful vacuum system with a large collection bin. It is also helpful if you attach shields (cardboard) to your sled, to help catch flying bits. It also helps if you enclose the immediate work area in plastic sheets to reduce air circulation carrying dust away.

My wife is still not happy!

Also, a router makes a lot of noise, so ear plugs do make sense, wood chips in your eyes are counterproductive, so glasses do make sense, and wood dust in your lungs may not immediately cause your demise, but we have Corona and face masks that filter tiny particles, so why not use them?

When you finally start planing the wood slice, it is best to work against the turning direction of the router bit and to lower it only a couple of millimeters at a time. If you work with the turning direction, the router will easily catch on the edge of the work piece and try to run away - not good!

If you try to remove too much material at a time, the work becomes tedious, you might move the work piece, and you might burn the wood and ruin your bit - all not so good.

Also, make sure to fix your work piece in place - I used wedges - because, though the wood slab might seem heavy, the router bit is exerting some pressure on the wood it‘s trying to remove, which will eventually move the piece - not so good.

So, as with all other projects: Go slow, take your time, don’t rush and think before you do!

With my router, I could best see what is actually happening where it cuts, if I work from back to front and with right to left sweeps across the work piece. Just try it on a waste piece of wood.

Tear-Out is a larger topic, that others have covered to great extent. Basically, it means that you should choose the correct router bit for your wood type and grain orientation that you want to cut. You also need to make sure to use the correct router speed and cutting depth, and…. - easy.

I tried different bit sizes, speeds, depths, pressures and got tear-out any which way I tried. With the router at full speed, I got lots of dust EVERYWHERE and the tear-out stayed the same - it was a bit frustrating. Since I am a bit lazy, I ended up taking a medium sized planer bit at medium speed and pushed semi-fast and accepted that I would need to do some sanding to remove the stripes after routing.

Go slow and concentrate - it‘s a kind of meditation!

When you have cut the wood to the thickness you want, still strong/thick enough to sit on, the surfaces need to be sanded.

On both my tree slices, I planed both sides - top and bottom - but only sanded down the top side, because I‘m lazy, and because I like to show that it is not bought in a store. I used a cheap electric sander from Parkside with 80 to 24 grit paper - it took some time - i.e. more Meditation!

To preserve and toughen the surface I decided to use a water-based varnish for wooden floors instead of oil. Because it is end-grain wood, oil will soak in almost indefinitely with the porous dry cedar, so a couple of layers of varnish work really well instead. The varnish also stabilizes the bark really nicely.

For the Cherry Tree and the Labyrinth side tables I made roughly at the same time, I had decided to over-engineer my own table legs.

With the two tree slices I decided to save some time and simply buy ready-made legs instead. After looking around the Net for some time and finally visiting the local Ikea, I settled on buying the cheapest wood stools and reusing their legs for my tables. Yes, I could have done four/legged versions, but I would have had to buy another stool and then are quite stale with three legs anyway.

The seats have been repurposed with small wheels as a base for my old shop-vac - another project….

The really simple and the bent wood ply legs actually look pretty good.

The smaller table was immediately adopted by my son because it fit perfectly next to his sofa.

The other made a nice present to a local public health advice center to replace a really banged up ugly and cheap Ikea version they wanted to throw out.

All are happy, so it was worth it.

I hope this has shown you how simple it is to build your own router sled to plane almost any tree-slices you might come across without spending large amounts of money.

Tree slices are beautiful and literally show you the passage of time, so I find it quite important to preserve some.

This way it‘s easy and doesn‘t take much work.

Ok, I had to sign them with my Labyrinth….

Always stay fascinated!