Worn spoon bits

[Harlan Barnhart]

I have been looking at spoon bits on Ebay, not because I really need them but just because. How worn is too worn? When the spoon part is worn back so that they look more like a gouge, do they still work?

[george wilson]

They need their ends to be cupped up or they won't drill. Are you aware that a spoon bit needs to have a starting hole made by a center bit(or an auger type bit?) It's the only way you can accurately start a hole with them.

[Harlan Barnhart]

Mr. Wilson, I'm not aware of anything about spoon bits. Just curious I guess. That's good to know.

[jamie shard]

The front of the bowl should almost look like a chisel, according to this factsheet: http://www.highlandwoodworking.com/modifyingcliftonspoonbits.aspx

Hope this helps!

[Harlan Barnhart]

Thanks for the link Jamie. That helps.

Mr. Wilson, what do you think of the sharpening recommendations on the link Jamie has provided?

[Rob Paul]

Even a worn spoon bit should be workable if sharp.
You can also buy shell bits, (which are shaped like a spoon bit with its spoon end removed entirely).
see
http://www.wkfinetools.com/hUS-borTools/z_Reading/bitStocks/bitStocks2.asp

[Harlan Barnhart]

Interesting Rob, maybe those "worn" spoon bits I was looking at were actually shell bits.

[Adam Cherubini]

They need their ends to be cupped up or they won't drill. Are you aware that a spoon bit needs to have a starting hole made by a center bit(or an auger type bit?) It's the only way you can accurately start a hole with them.

What? No, that's not right George.
Spoons are spoons, shell bits are shell bits. Most shell bits people see on ebay were never spoons. Spoons are fairly specialized tools.

Shells are fantastic tools and make holes quickly and accurately and typically cause no break out. You sharpen them like a carving gouge. A finger nail profile works well. It's true that these tools don't cut the center of the hole (which I find particularly efficient- they remove a donut, so large sizes work particularly well) So you start slightly offset from the hole's center. Tho most of us swing our braces only one way, these tools are sharpened on both sides. In my experience, using these for many many years, I find I ratchet the brace to position hole accurately. Ditto for spoons. I can do fairly well with this. Certainly better than with a standard twist drill.

Other than a good sharpening, there's no trick to these tools. Both shells and spoons cut only with the end. They are not reamers (side cutting).

Shells are used for cutting smallish (usually under 5/8" dia) deep-ish holes. They don't eject chips, so you have to keep that in mind. I think they produce holes of slightly better dimensional accuracy than a center bit would.

Spoons are used to start holes in round stock primarily. They typically produce a shallow cut (typically a few diameters). Until the full bowl is cut, you can change direction fairly easily (meaning you can start a hole perpendicular to chair rung for example, then change it's direction. Additionally, they allow for a deeper blind penetration then other period bits. Honest injun, for cutting perpendicular holes in round stock, most less experienced users will find center bits FAR easier to use. Most importantly, spoons uniquely allow you to create holes at incredibly low angles. No other bit can do this. The trick is to start the hole perpendicular to the work surface.

I do demonstrations with these bits at Pennsbury Manor. These are tools that I use to "hook" an audience because they look so crude and work so amazingly well. Every visitor has had personal experience drilling holes (few have had experience surfacing stock for example).

These bits are on my "endangered" tool list. People don't still make center bits or shells (tho some spoons are still made). Most people don't know how to use or maintain them. When folks start figuring out how great they are, I'm afraid the usable tools will be gone. Please be careful restoring and conserving these. Center bits must be stored carefully, not thrown into the bottom of a rusty coffee can or tossed into a draw of rusty twist drills.

Adam

[Harlan Barnhart]

Thanks Adam, thats some useful information.

[Kevin Adams]

Hi Harlan,

You probably know this already, but LV has been selling spoon bits for a while now. I was actually involved with testing them a few years back and they work well for (I think) a very reasonable price. They are not quite as good (or aggressive) as my favorite bits from Fred Emhof (if he's even still making them), but they do the job.

I use spoon bits all the time (mostly for chairs) and once you get used to them, they are very versatile. George is correct in that it can help to start the hole with an awl or small gouge particuarly in delicate areas, but once you get the hang of the offset required (which varies by bit diameter), they are not too hard to steer for where you want the center. The shavings are fun, too (old chairmakers called them "turds"!). And nothing could be easier for maintaining their sharpeness...I just strop them after each use and they are ready to go.

Take care,
Kevin

[George Neill]

They need their ends to be cupped up or they won't drill. Are you aware that a spoon bit needs to have a starting hole made by a center bit(or an auger type bit?) It's the only way you can accurately start a hole with them.
I have to dissagree with both statements. Shell bits are open-ended and work very well. Spoon bits definitely do not require a pilot hole. Windsor chairmakers have been boring accurate holes in seats, legs and rungs with spoon bits for centuries.