Using Spoke Shaves

H

HSteier

Well-known member
I am currently in the process of making six Federal shield back chairs. In the process I have been using spoke shaves to smooth the surfaces of the legs. On the convex surfaces of the legs I have no problems. However on the concave surfaces, no matter what kind of spoke shave I use (traditional wood, modern Stanley metal shave, or reproduction cigar shave) I get a lot of chatter. The blades are sharp (I've been doing would work for about 15 years and I know what sharp is). Is this chatter inevitable on concave surfaces because of the partial cross grain aspect of the concave surface?

All help welcomed.

Howard Steier
 
Are you using a spokeshave with a radiused sole on the concave surfaces?  Is the radius of the spokeshave less than the radius of the concave surface?

I'm assuming that you are using a concave spokeshave with a radiused sole because I don't know how else you would work a concave surface otherwise - although you may be able to work slightly concave surfaces with a small wooden spokeshave.  The problem is probably due to the fact that the depth of cut is controlled by how the sole of the spokeshave pivots on the wood.  As the shave leans forward or backward on the radius of the sole the depth of cut may be deepened, reduced, or the cutting may cease altogether.  In practice the pivoting of the sole's radius on the wood results in a choppy chattering cut as the depth of cut varies or stops as pressure is applied throughout the cut. 

Keeping the sole of the spokeshave in a consistent position to achieve a consistent cut is difficult even on a straight board.  As you have to adjust the position of the spokeshave through a curve in the work the challenge is even greater.  I would reduce the depth of cut which should make it more obvious when the angle of the spokeshave changes and limit the effect of the chatter.  You may also be able to skew the spokeshave slightly if the radius of the concavity will allow it since this will present a wider bearing surface that is easier to control.  The only other advice I can offer is to check your grip on the spokeshave.  Your thumbs should be in front of the mouth of the shave with the index fingers behind the blade - almost a pinching grip.  The other fingers rest on the handle and don't do much work.  You may be able to google and check out some common spokeshave grips.

Hopefully this info helps.

-Phil
 
Howard- Good advice from Phil. I think you need a shave with a narrow sole like an old wooden one. This will maintain sole contact in front of and behind the blade. Your chatter is coming from the blade having to reach to get to the wood, or because it's set too deep, I think. It's just a small plane.-Al
 
Howard,

Have you tried a "Spoke Scraper" ?  I have made several of these.  For the inside curves, I round the plane sole with a #12 Hollow plane.  They work great!  I did a Chapter presentation on how to make them.  See the attached Word Document for those Instructions.

Cheers,
David
 

Attachments

  • How to make a spoke scraper.doc
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Thanks Dave

I actually have one of these. Paid an exorbitant $80 to Woodjoy tools. It's nice and does the job of removing chatter but it's sloooowwww. It would take forever to use it for shaping which is my objective. When I cut the legs on the bandsaw I cut proud of the outline and then spoke shave to the line. A scraper would take forever. A rasp works but I tend to round over the edge with the rasp where as with a shave I tend to get a flat square surface.

I still ended up with a fair amount of chatter last night. My objective was to try not to resort to sandpaper for smoothing (I'm obsessing about the 18th century) but I suspect I'll be using Mr. Norton after all.

Howard Steier
 
For the metal-bodied spokeshaves, try putting the blade in upside down. It doesn't always work, but in some cases having the bevel up as opposed to down gives the tool a different cutting angle. Once in a while it's an amazing difference, and costs nothing to try. The first time I did it, it was an accident.

And don't forget a regular cabinet scraper. if you want to keep flat faces it will help.
 
LOL @  I suspect I'll be using Mr. Norton after all.

And, whats wrong with sandpaper? I would bet a fair amount that furniture makers in the 18th century would have used it had it been available. I agree if restoring an old piece, sandpaper is kinda a big no no if refinishing because it removes the patina on the surface of the wood however, i think it's appropriate to use on reproductions of period pieces.
 
The question of the use of sandpaper in the 18th century came up about 2 years ago.  According to answers.com,
"coated abrasives date as far back as the thirteenth century, when the Chinese used crushed shells and seeds glued with natural gum to parchment. By 1769 coated abrasive paper was being sold on the streets of Paris".

If you Google "history of sandpaper" you will find many articles about it dating way back.

I'm not sure but I thought that the cabinet shop at CW told us that sandpaper was used in this time period at CW.  Somebody correct me if I am wrong.

Dennis Bork

 
I have recipes for period glass paper but what about scrapers after the shave but before any abrasives? Any abrasive would be the finial step.  There are many period alternatives for abrasives from shark skin to reeds to brick dust plus. Please realize stains are absorbed differently from scratched to cut surfaces as I am sure you are well aware.
I love my spokeshave!!! With most tools if you are not living on the edge then you are taking up too much room.
 
Well, there's nothing wrong with sandpaper, and the question regarding whether abrasives were used in the 18th century has been banged around at the colonial Williamsburg conference for years. I remember one year when Jeff's brother Mac indicated that in Williamsburg there were no documented references to use of manufactured abrasives there in the 18th century (this was based on inventory lists/sales data etc.) I profess to be no expert.

On one occasion I was visiting the Hay shop and talking with the staff there about 18th century surfaces. One of the craftsman (I can't remember his name, he was the gentleman who did the tool chest project several years ago) went to his workbench, came back with some European rush and demonstrated that it worked perfectly well as a 150 grit sandpaper, though it was mighty slow.

Again I was just obsessing about the 18th century and hoping to get a smooth surface with just edge tools.

Jeff, you don't know me that well but I am edgy and I do live on the edge.

Howard Steier
 
One of the tradesmen at the silver shop at CW told me that they had and used emery cloth in colonial days at CW.  Abrasive papers were around according to this.

Dennis Bork
 
Howard,

Continuing on with the spokes scraper discussion: 

I would still use your spokeshave to get close to the line.  I would only use the spoke scraper to remove the spokeshave chatter. 

The spoke scraper bevel angle is another consideration.  If you use the standard cabinet scraper style 90-degree edge, it will do finishing work, but it is slow.  I use a 45-degree bevel angle (see L-N site on sharpening a scraper plane) on most of my spoke scrapers.  This is a more aggressive cutting action and is great for coarse work.  It also dulls the blade faster, so I try and use the hardest steel I can find for these scrapers.  They will definitely get rid of your chatter marks and/or tear out in a hurry.

Cheers,
David
 
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