Thread: How to cut a bevel on a wide piece of timber?

Originally Posted by TongueTied

I'm trying to make a coffee table which is 50mm thick and a single piece that is about 600mm wide by 1.5m long. To lighten the appearance, I want to put a bevel on the underside, all the way around. The bevel would probably be at about 20 degrees to the horizontal leaving about a 15mm vertical edge to the table. Any suggestions how I might do this? I think it could be done on a table saw but with the dimensions of the table top, I don't see how I could do it safely. I do have a No. 6 plane so I could do it manually. Any other suggestions?

circular saw with a piece of angle iron as a guide

I think the easiest is to use a hand saw and finish it with a plane. You can also have the table sitting inclined at 20 deg and use a router but that would involve building a jig.

Track saw?

Is there a router bit with the angle you're after? I have used them for 45 deg, but they may have one at a specific angle

Tilt the fence is the logical way, its just a question of depth as to whether its the fence of a circular or a band saw.

Thanks. I hadn't thought of a circular saw or track saw. That would probably work.

This isn't hard, just use a circ set at 20 degrees and a straightedge clamped down, as posted previously. A spirit level will do as a straightedge if you don't have any angle iron, or buy some aluminum box tube from an ally supplier. A decent straight edge is always handy to have.

Practice on scrap to figure out the offset you need (how far in from the edge you need to clamp the straightedge to get the cut you want). Then it's just the straightedge being clamped in the same distance from the edge, for all four cuts. I'd do the end grain cuts first, so the any tearout will be cut away when you do the long grain cut.

When you say a 20 deg bevel, do you mean a bevel that's 70 deg between the top and the sides, or 20 deg between the bottom and the sides? If it's the former, then you can safely use a straightedge as the others have explained. If it's the latter, you could set the circular saw to 20, and being very careful, with the saw fence riding on the top (assuming you want a bevel on the bottom, and not going all the way to the top) of the table, cut it. I've done it this way, but I must admit I never feel terribly happy about it.

If you do it this way, be especially careful that the saw doesn't drop at the start & end of the cut. All the usual circular saw precautions apply, in triplicate. Also, allow for a bit of planing to clean it up, in case the saw wobbles a bit on the edge.

Originally Posted by TongueTied

I'm trying to make a coffee table which is 50mm thick and a single piece that is about 600mm wide by 1.5m long. To lighten the appearance, I want to put a bevel on the underside, all the way around. The bevel would probably be at about 20 degrees to the horizontal leaving about a 15mm vertical edge to the table. Any suggestions how I might do this? I think it could be done on a table saw but with the dimensions of the table top, I don't see how I could do it safely. I do have a No. 6 plane so I could do it manually. Any other suggestions?

is your plane blade sharp?
if yes, you will have the job done using your #6, before you finish fiddling around making a jig to do it safely with a table saw or circular saw. Remember to do the cross grain cuts first, and it's easiest to just work to a pencil layout line.

if you have a router, edge guide and a "sort of suitable" bit you could knock the first 30mm off the edges with the router.

Done this before with an electric planer and finished with a hand plane. Not quite that much though. It'd just be more passes.

20degree.jpg

A 20 degree undercut bevel as illustrated in the quick picture I made?

I do this type of thing often enough, for the exact same reason as you, to lighten the look of the tabletop. I wouldn't do 20degrees in 50mm material leaving 15mm at the top though, because as you can see, the length of cut is ~100mm. My panelsaw can only cut approx 80mm high at 90degrees. I would increase the angle so that I could make the cut in one pass on the panelsaw.

My panelsaw only has a fence to the right of blade, and the sawblade tilts towards the fence. I screw a piece of MDF to the fence with a cutout to accommodate the sawblade and cut it with offcut hard against the fence. However! if I do this I can guarantee that the offcut which is wedged between blade and fence will shoot out like a rocket which isn't such a big deal to me, but when it kicks back it pushes the blade over and leaves a mighty gouge in my tabletop which will need to be planed out. To avoid the kickback, I just turn all of the offcut into sawdust using multiple passes so that on the final pass there is no offcut to be wedged between blade and fence.

Its a pretty good way to do it I reckon. Even if you are unstable with the tabletop held on edge and wobble it, it usually cuts less material (good) rather than cutting too much (bad....oh soooo bad!)

Originally Posted by Kuffy

20degree.jpg

A 20 degree undercut bevel as illustrated in the quick picture I made?

I do this type of thing often enough, for the exact same reason as you, to lighten the look of the tabletop. I wouldn't do 20degrees in 50mm material leaving 15mm at the top though, because as you can see, the length of cut is ~100mm. My panelsaw can only cut approx 80mm high at 90degrees. I would increase the angle so that I could make the cut in one pass on the panelsaw.

My panelsaw only has a fence to the right of blade, and the sawblade tilts towards the fence. I screw a piece of MDF to the fence with a cutout to accommodate the sawblade and cut it with offcut hard against the fence. However! if I do this I can guarantee that the offcut which is wedged between blade and fence will shoot out like a rocket which isn't such a big deal to me, but when it kicks back it pushes the blade over and leaves a mighty gouge in my tabletop which will need to be planed out. To avoid the kickback, I just turn all of the offcut into sawdust using multiple passes so that on the final pass there is no offcut to be wedged between blade and fence.

Its a pretty good way to do it I reckon. Even if you are unstable with the tabletop held on edge and wobble it, it usually cuts less material (good) rather than cutting too much (bad....oh soooo bad!)

I've got both blade tilt and fence tilt on mine, so that cut would be a single pass no problem matter... tilt the fence. I hate that blade tilt business for exactly the reason you mention - cast iron doesnt saw well.