Chamfering concave edges

[Brian AdamsMS]

I'm in the process of building a bassinet for grand baby #2 that's due in February (gloat :)!!).
I have a small assortment of chisels, planes and files, but no spoke-shave. What are my options to getting a good consistent chamfer (maybe 1/8") along a concave surface? I have done chamfers with a small block plane on straight or convex edges with no problem. Just not sure how to attempt this without a tool purchase or worse resorting to using a router. So far my project has been all hand tool and I would like to keep it that way.
272684

[Derek Cohen]

Round bottom spokeshave or model makers block plane.

Regards from Perth

Derek

[Zach Dillinger]

I agree with Derek.

[glenn bradley]

+3 on a shave. The LV LA shave (http://www.leevalley.com/US/wood/page.aspx?p=44834&cat=1,41182,44834) is inexpensive and does mild concave runs quite well while being useful on straight runs too.

[Judson Green]

+1 And not that ya need a reason to buy another tool but...

You could possibly do what you want with careful marking and files.

[Brian AdamsMS]

I think yall have talked me into a new tool purchase. 'But honey, its for our grand child!' ;)

[Prashun Patel]

That curve is not too concave. I'm all for a spokeshave; it's probably the single most enjoyable tool I own, but by skewing a small block, you can chamfer the edge just fine. You know from working convex edges that grain direction is critical on these types of surfaces, so you usually have to work in (or out - i forget which) from either side.

[Bill McDermott]

Brian, I love spokeshaves, and one will work great for you. Be very conscious of cutting "down" but never "up" on that curve. Of course that makes the bottom of the arc a bit of a tradeoff. Having said that, sand paper on a stick will get that project done and out of the shop before the new tool arrives. A 1/8th chamfer will take no time at all to just sand off. For shame, two replies suggesting sandpaper in no more than a few minutes. By the way, I like the lines on the basinet. The extra trouble to add the curves worked out well. Bill

[jason thigpen]

+1 on the Lee Valley low angle shave. Inexpensive and very versatile.

[Jim Matthews]

If you've got a very sharp marking knife, whittling is a legitimate approach.

Wrap the knife in two places with heavy masking tape, to leave a small portion of the blade exposed
between the two wraps. Alternately, cut a 90 degree notch in a long block of wood, with a fine kerf to hold
the knife blade. Cut the kerf across the notch so that the inserted knife faces the front of the block,
with the edge exposed.


The kerf will reveal the amount of chamfer you cut.

[Bill Houghton]

A flat bottom shave should do that shallow curve just fine. and you don't need fancy; a Stanley 51 or 52 (I like the 52, which I can mention now that I own three) will do fine.

[Jim Koepke]

+ another 1 for a round bottom spoke shave.

jtk

[Sean Hughto]

a chisel - bevel down

[Derek Cohen]

On the topic of spokeshaves ...

A round bottom spokeshave is the correct tool for curves ... BUT it is also less easy to use than a flat bottom spokeshave, and for such a shallow curve it may be overkill. Of course, don't let this put you off the new LV SS spokeshave, which seems ideal. :)

The flat bottomed LV LA spokeshave will do this job very well. The issue is how much curvature will defeat a flat bottom spokeshave? I did attempt to deal with this question when reviewing the HNT Gordon spokeshaves some years ago. Here is an illustration from that article ...

http://www.inthewoodshop.com/ToolReviews/THE%20HNT%20GORDON%20SPOKESHAVES_html_68186030.jpg

The review is here: http://www.inthewoodshop.com/ToolReviews/THE%20HNT%20GORDON%20SPOKESHAVES.html

Regards from Perth

Derek

[Chris Griggs]

+ whatever number we are up to now on recommending a spokeshave. I have and can recommend the LV LA shave as well. Has a very nice slow slicing angle that greases through curved chamfers. I actually use it quite a lot for end grain chamfer like one would use a LA block plane.

I have the new LV little cast stainless one too, but have only taken it out for a couple test cuts. Very nice shave though...the LA shave is better general purpose shave but with what little (and it has been very little) I've used the little SS one it will do this job with ease and a lot of comfort.

Really any round bottom shave will do, and likely a flat bottom will too if the curve is gentle

[Bill Houghton]

+ another 1 for a round bottom spoke shave.

jtk

I'll disagree. Round bottom shaves are tricky tools; it takes a while to learn to use them. I've worked the mild curve shown in the original picture plenty of times with a flat-bottomed shave, which is far easier to learn how to use. My impression is that Brian would be new to spokeshaves; let's not start him out with a frustrating shave.

All that said, Brian, if you do decide on a round bottomed shave, get a decent one, and, when you use it, set your work up so that you're pulling the shave toward you. The body mechanics work out better that way.

[Chris Griggs]

...set your work up so that you're pulling the shave toward you. The body mechanics work out better that way.

Very very true!

Bill also makes a good point about the round ones being harder to use. I wouldn't say they are particularly difficult to use on something like a chamfer, but a flat bottom is easier. Perhaps another good reason why the LV LA shave may be a good option. You can set up up with a flat toe or rounded toe, and use whichever works best for the given situation.