Edge finishing

[Ian Smith]

Folks, I've done a search of this forum but haven't found anything on this ( maybe I haven't used the correct words) and it seems like a very obvious question, but here goes. How do you put that small radius on the edge of what is essentially intended to be a square finish?
Do you just use a sanding block, elbow grease, and practice, or is there a tool or router bit to get a consistent finish?
Corners in particular I find a real pain, as it's difficult to get a nice, consistent, small radius on all three edges that looks right at the point where they all meet.

[Bob Willson]

Use a 1/4", 3/8", or 1/2" round over bit in a router.

[echnidna]

I just use a bit of 120 grit paper by hand, usually without a block. It only needs a couple of rubs to take the sharp edge away but still leaves it as a nice square edge.

[Harry72]

I now use 3 strokes with a spokeshave and round it with some paper and just paper it on the corners, used to router it with a 3.2 round over ...but hit a slight bump or divot in the wood and it looks horid!

[Bob38S]

Router mainly but occasionally sanding block.

[journeyman Mick]

Ian,
do you want to put a quarter round on the edge or do you just want to knock the sharp bit (arriss) off? If the latter, I just pass my block plane over once or twice. If the former, I use a R2.4mm rounding over bit in a trimmer.

Mick

[Lignum]

Ian,
or do you just want to knock the sharp bit (arris) off?


Say no more - spot on:)

[BobL]

Free hand routing of 3 edges that meet at a corner is a bit tricky especially when you get very close to the corner as the router can tip off the leading egde and muck up the rounding. The trick is to keep the trailing router handle firmly inside the quadrant with the supporting edge. If you want to be sure you can always clamp the workpiece together with other supporting pieces of the same thickness so that the router runs onto the supporting piece as it approaches the corner. You have to get the two pieces absolutely flush with each other otherwise the router may still jump or dip as it crosses the join. This method can be particularly useful for routing the shortest dimension of a board (ie the thickness) where you have no leading and very little trailing support.

A router table avoids these problems - of course you cannot ways get the object you are trying to edge (eg kitchen benchtop) onto the table.

[Ecc]

I've also found a low angle block plane set fine is the way to go. If you set it fine its very controllable as to how much you take off.

[Ian Smith]

Gents, thank you all for your responses.
I’m beginning to think I’m being too picky because you all seem to be getting by – still it seems that the subject has been worth exploring.

Bob Wilson – I’ve looked at the generally available rounding off router bits, but the radii you mention are all too large for what I want.

Echidna – Yep, that’s what I’ve been doing, but I always seem to end up with what’s in the attached thumbnail – and that’s not mine, that shot is from a cabinet maker who did some stuff for us before I was “Tritoned”.

Harry – Wots’s a spokeshave ??? Just kidding mate – but I wouldn’t trust myself with one of those things – anyway it hasn’t got a power cord, so what good is it?? The 3.2 mm radius bit is a bit too big - if you’ll pardon the pun.

Bob38s – see above comments

Journeyman Mick & Lignum – Yep , just want to knock off the sharp edge, but I’d also like to do it consistently, so a small radius would be nice, but I reckon that it needs to be around 1.0 mm, and no router bits I’ve seen go down this small.

BobL – I do have a router table, and you're right, hefting a large item would be difficult, but I was mainly intending this sort of finish for cabinet doors and the like, so I think most times they would be manageable – however we get back to the problem of the available bit radius
<O:p
Ecc – see Harry above.

Many thanks
<O:p
Ian

[journeyman Mick]

Ian,
I've got some 1.6mm radius bits but even that is a fair bit to knock off a square edge. I use a low angle block plane to just take the merest whisker off, works fine on the end grain as well. Pretty standard practice in joinery work, your average door and associated jambs and architraves have about 35 - 40 lineal metres of timber that needs to be arrissed.

Mick

[fletty]

Veritas make 2 little hand tools which you drag along the edge to get 4 different and consistent very small radius roundovers. I bought mine at Carbatec but they're available at many other places. As it is a 'cutting' action you need to be aware of the grain direction. My normal method however is to reach into the pocket and give the edge a couple of wipes with the block plane. Fletty

[Iain]

Those little edging tools are good until the grain decides that a bit more can come out and you finish up with a splinter coming out that was never part of the grand plan.
Easy to sharpen though with the jig provided and a bit of wet and dry.
The plane, I think, has more control.

[Auld Bassoon]

You can use a router bit (preferably in a table to ensure a consistently straight line) and use round-over bits or chamfer angle ones (eg 45 or 22.5o) - or you can use something like a LV block plane with a chamfer guide.

Doing this sort of thing purely by eye / hand is unlikely to result in a clean intersection at the corners.

[journeyman Mick]

..........Doing this sort of thing purely by eye / hand is unlikely to result in a clean intersection at the corners.

If you're only arrissing it (just taking the sharp corner off) with a plane then I doubt that anyone will notice any irregularities unless they check with a jeweller's loupe. If you're going to take more off (ie a 2mm radius or chamfer) then, yes it will be noticeable.

Mick (who's probably arrissed at least 2kms of mouldings on every house he's ever worked on)