[Thomp]

When i cut a straight razor out to a carving knife,
i remove the thick back while shaping the blade and if im careful i can keep the heavy backbone of the razor intact with the scrap of the tip of the razor, which in a lot of cases is more than enough to shape out a micro blade with,

Now im a real fan of full tang construction with any big hunting knife, but lets face it were not dealing with dressing game, or splitting kindling for a fire, like we would with our kbar's
These small carving knives are hard sharp bits of carbon steel that work perfectly for there job,

and it bothers me to grind down a great 4" straight razor to a 3/4" nub of a detail knife. when these bits could be used just as well,

now these macro knives are pretty brittle, they wont take much twisting or being used as picks or levers like any detail razor knife, but they hold an edge and do very well on little tight places that normally go un-detailed because the space is just not excessable with other knife.

so i took a second look at the straight razor bits and pieces i had laying around, and thinking that dockyard tools tang are about 1/8th inch stock, while the scraps of razors are bigger at the back edge, but may wind up short on tang,

as i understand the workings of a tang of a micro knife, it is something to epoxy into hardwood handle and should be fit enough to support some leverage but how long is long enough for a tang? one or 2 inches?
ground straight razor tangs on the knives barely reach 1-1/2 or 2"

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Another question on another situation im coming up with is by the time i get a knife made with all the grinding and polishing i do , they are somewhat magnetic,
is this a problem? that i don't know about?

the 2 questions im addressing

1. how long is the minimum for a tang on a 1/2 to 3/4" macro knife.

2. is a magnetic blade a bad thing.. metallurgically?

[Claude]

Thomas:
Take a look at an Exacto knife blade tang - for a blade about 1/25 inches long, the tang that is clamped in the holder is only about .5 inches long. So, I'd say anything more than a half inch tang, epoxied into a hardwood handle, should be plenty strong enough to use as a micro knife - given that you won't do any twising, prying, or firewood-splitting with it...

Clalude

[AlArchie]

Thomp, do you mean magnetic or magnetized. Some stainless steels are not magnetic...a magnet will not attract that particular type of stainless steel.. Some stainless steels ARE magnetic.

All carbon steel blades are magnetic to some degree and can be magnetized, or made to have permanent or temporary magnetic properties. The only drawback I can see to having a magnetized blade is that steel debris from sharpening will be attracted to and stick on the blade. That could cause some premature dulling of the blade.

Demagnetizing a blade is fairly simple with a tape demagnetizer available at Radio Shack or any other electronics store. Just hold the blade near the demagnetizer, plug it in or turn it on and after a few seconds remove the blade from the field while the unit is still turned on.

That should remove any magnetic properties from your blade.

Al

[Thomp]

Al,

i got a tape old demagnetizer here i think, i didnt know how to use, it thanks al,
im really afraid to in the same house with a computer in it i have heard some evil stories bout that..

these razor blades will all rust there all used and stained, lot of carbon in the steel, maybe some nickle, and a lot of my knives get magnitised, its a henderance when the knife blades if they get close togather or im trying to take a picture they are like misbehaving kids.. without the handles..

metals now days are hard to determine there construction without spectral analys (sp) there is so many with cromium and monivelenium and other mixtures you never really know..

Cladue
the exacto system is ground and fitted to the ferrel and the ferrel makes a tighter connection by design than anything i know of. wish i could mount them that tight..

i guess an experiment is in order

thanks guys

[Just Carving]

Thomp,

When I make my knives, I usually try to keep the tang about an inch or so. But if it's a piece of scrap metal, I make the best of what I have to work with--meaning, I shorten the blade length, and shorten the tang. So, for a piece steel 1 1/2" long, I might make the blade 7/8" and the tang 5/8". So, I guess my rule of thumb would be 2/3 to 1 times the length of the blade up to and inch, and then after that, 1" to 1 1/2" for longer blades up to 3 inches--so probably a minimum of 1/2 the length for the longer blades. The other thing to remember, the thicker blades will give you a little more strength, so sometimes you might be able to compromise on length if the tang is thicker.

One thing I do to make the gripping of the tang into the handle stronger when I use the 2 part epoxy, is I make small cuts into the tang maybe 3/64" deep, maybe a 1/8" to a 1/4" apart staggered on the top and bottom sides of the tang with respect to the handle, i.e. the narrow sides of the tang. Pardon my crude sketch, but I think you'll get the idea.

Until you mentioned it, I hadn't given any thought to demagnetizing the blade--and I have a couple that hold the filings when sharpening like Al mentioned. But I just wipe the filings off before I strop the blade. So far, I haven't noticed any problems.

Something else I forgot to mention, if you make the tang wider, and thicker, you probably won't need to worry about breakage. Then it's just a matter of having a good grip in the handle. You make the cuts like I've shown, I doubt the blade will come out of the handle. I've used the polyurethane water reactive glue, and the blades held when I wanted to change the handle. With a bit of effort, I was able to loosen the blade up. With the epoxy, the birch, oak, or maple handles split first. So, that tells you how tough they are.

[Hi_Ho_Sliver]

I have made several knives that are a bit shorter and used the extra straight razor length to make a small detail knife....I had a minimal length for a tang, and just ground notches in both sides so the glue has something to adhere to, no problems.... I too have a question for our residence metallurgists? Is the tang of the straight razor tempered the same as the razor itself? seems like a lot of good steel to waste cutting off or putting in a handle...enough metal there to make a good detail knife? thanks Dave

[Thomp]

Bob & Dave..

thanks for replying.

The razors are plentiful on eBay for 5-10 bucks each delivered to the house, i just dont to be wasteful, all that ebay crap is time consuming and confusing

just remember your not buying antiques and check daily i got several good ones to the house for just under 3 bucks before but there the rare occasion to get a German razor for that price,
when plucked like a guitar string a good razor will usually sing, if it don't i use a diamond file on it to see how deep it cuts into the steel, in one stroke,
if it skitters off without scratching it, its special and marked MINE! the rest are good steel but just barely a difference.

in the picture:
1. the small detail blade was ground out of a morris German made 1/2 sculptors straight razor.. its 1/8th inch longer than the scrap. but i did fracture off 1/8th inch of the tip giving it the torture test the tip was ground to thin, but whizzed through basswood like butter...even un epoxied just pinch pushed into a round hole in the handle i use for socketing the blades like rick,

2. as you can see the scraps much resemble a comma with a straight tail,
the 2 scraps (size relationship hard to tell from photos) but the big scrap is 4mm thick across the back, 2-1/4" long and cut from a 3/4" razor. and to make a mini rat tail shaped knife out of it it would leave over an inch of tang and a one inch blade, because of the thick backbone in the extra hollow ground razors there is a lot more meat in the backbone,
the other scrap is 1/2 less

my concerns were:
about the long taper being used as a tang because its hard to grip a taper unless i modify it with groves like bob mentioned. or heating the tang and bending over the end to a hook or a knob.

i have used polyurethane adhesive on lots of knives, lot of the warren blades i set into a maple flexcut type handle were socketed really tight and had plenty of extra wood strength to hold against, the holes was a succession of 1/16" side by side holes and then the dividers were drilled out to make a slot,
its a long and tedious process to basically drill a slot but it worked with the polyurethane because its a epoxy type air/moisture foaming action which can be suppressed or stopped by wrapping the glue joint with plastic baggies material it forces the foaming action to stay in the socket and cure there not outside in a fomey mess on the blade,,

but the short tanged frost pocket knife blade convert to a pelican type blade failed in the same socket i think because it was mounted in southern walnut which is softer than northern walnut , it was also 2 slabs glued up, so it had lots of things against that mounting, the blade was saved and will be remounted as i ground it down to make a 1-1/2 " tang and plan to brass pin through the henge hole in the blade to make it extra secure.

ok im rambling now, but maybe i got some of the information im dealing with across, i do rough up the tang and cut some dimples into it with a grinding wheel or belt just before i mount the blade, i don't know if the picture shows it, but i do,