How to sharpen a Glass Knife

[coopieclan]

This is a glass food knife from the 1930s.
Made in U.S.A. I got it at a flea market.
It is a 1930's cutting and serving utensil.
Ones like this were sold at the 1935 Worlds Fair.
Before stainless was so widespread it was a problem for knives being stained by citrus
I should have taken a picture when it was damaged.
There were nicks all along the blade. So I used emory cloth to take away the damage.
I used the emory cloth on a block of wood like a stone.
Medium then fine.
The glass needs a more shallow angle than a metal blade...I don't know what angle I just copied what was there.
Now the edge looks clean but it is not sharp enough to cut a tomato.
How do I sharpen this glass knife?...I don't think I can use my Spyderco sharpener.

[primersp]

try with an diamond file
good luck

[swheeler]

Try a diamond hone.

[Matt3357]

Super fine abrasive of some sort. The edge will be super brittle so super light pressure would be my advice. good luck and let us know how it turns out.

Matt

[JIMinPHX]

Diamond impregnated stones have gotten pretty cheap these days. That would probably be my first choice. I seem to remember that Spyderco makes a ceramic stone with embedded sapphires. If that's the rig that you have, chances are that it is hard enough. Alternately, if that emory was a good enough abrasive to take the edge down, then maybe you just need to hold the emory flat on a better surface while sharpening. Maybe the wood isn't good enough? These are just ideas off the top of my head. I've never sharpened glass before.

[StrawHat]

I don't believe that knife was used for tomatoes, but rather for lettuce. Back when that knife was produced, most kitchen knives were made from carbon steel and would discolor lettuce when used to cut it. The glass knife was a rather elegant solution to the problem.

As for sharpening it, using finer grits of abrasive paper is a good way to go. I have a jig I built to hold the paper and use a stropping motion to hone knives. For your glass knife, a blunt angle will be needed to prevent the edge from continually chipping.

[Wayne Smith]

Ideally find a lapidary store or hobbiest in your area. They will have everything you need and more.

[kmag]

I would try the finer grades of wet or dry sand paper backed by a flat surface. See how that worked. Or you could get diamond spray with diamond mixed with oil and use on hard leather backed by a hard surface. You can get get the diamond spray from Lapidary shops or you can order it from any number of lapidary suppliers. Bottle I have came from Graves Company, 950 S.W. 12 Ave., Pompano Fla. 33060. This bottle was bought back before the internet was developed when I was cutting gem stones. The spray came in 600 to 100,00 grit at that time. Sure you can find them on the internet now.

[thehouseproduct]

Very cool item.

[Jim]

I have one of THESE (http://www.amazon.com/Diamond-Knife-Sharpener-Sharpening-Stone/dp/B002MLE5E2) and it does a really good job. My wife has a set of those ceramic knives in her kitchen and I can put a shaving edge on them with this stone.

[M-Tecs]

In the day you could have them sharpened for 25 cents. That included return postage. http://www.auntjudysattic.com/About_Glass_Knives.htm

[shooterg]

My wife has a bunch of those glass knives in different tints, some with the original boxes. I thought they were maybe for cakes . ANd I don't trust her with a SHARP one....

[GT27]

My wife has a bunch of those glass knives in different tints, some with the original boxes. I thought they were maybe for cakes . ANd I don't trust her with a SHARP one....

Same thing my wife said,usually used at weddings for the cake...:bigsmyl2:

[Swede44mag]

I would put it in a frame to look at to neat of an item to risk breaking let alone what it would do to the chef using it.
Glass shards might not be to good for the digestive track.

[StrawHat]

In the day you could have them sharpened for 25 cents. That included return postage. http://www.auntjudysattic.com/About_Glass_Knives.htm

An interesting article, I learned a few things. Sharpening for two bits. The ones I have seen never took the company up on that offer.

[Mk42gunner]

Interesting item and article, but I am inclined to agree with Swede44mag on this one.

Robert