Project Idea

[NEIKOS]

I'm thinking of attempting to make myself a titanium bladed, carbon fibered handled knife.

Anyone have any knowledge about metal casting or carbon fibering?

[ryandalling]

Don't do it. You might cut yourself. 

[duc_fan]

Titanium is notoriously difficult to work with.  You won't be casting it at home, nor even in any "normal" casting facility.  Ti requires significantly higher temps than steel.

Ti is also ugly to machine.  Some shops won't even touch it.

If your heart is set on a Ti blade, I'd be trying to find a chunk of Titanium that very nearly resembles the desired final shape.

If you want something you can work yourself, you'll need to stick to a softer metal.

CF is significantly easier to deal with.  Pick up a copy of the Aircraft Spruce catalog, and check out the available composite cloths that are available.  Unless you've got an autoclave, or an oven you don't care about, don't bother with pre-preg (which is fiber cloth pre-impregnated with resin).  Get plain cloth, then you'll need an appropriate resin.  You'll have to determine what material properties you're looking for (fast set, slow set, very hard but brittle, medium hardness with a little give, soft with lots of flexibility, etc).  I'd imagine in a knife handle that you want something with a little give to it, so it doesn't shatter the first time it gets dropped on a hard floor.

We can easily wrap a knife handle with CF fabric and resin.  We could probably even get creative and vacuum-bag it (reduces air bubbles, resulting in a better looking and stronger finished product).  The biggest challenge will be creating the knife blade, and as I said earlier: if'n you want a Ti blade, you'll need to find it pretty much finished, because there's no way for us mere mortals to work Titanium in the average garage.

[Betty Rage]

My brother is a welder and works with many different kinds of metals along with CF. I can put you in contact with him.

[Mother]

Or

you could go with bone and steel...


I made this one in high school

The blade is a piece of a blade used to cut metal

composition unknown and a frightful nightmare to work

but it rarely rusts and when it does it just gets minor black spots

It is a 5 1/2" Drop Point Flat Grind with a half tang

The Quillan is brass and mostly unfinished

The hilt is Deer

I was unable to drill the tang so it is fixed into the hilt with epoxy










I would highly suggest you invest in a machine to do your polish

this one is done by hand to 2500 and it took a considerable amount of time

[oregunduc]

I like the book in the background of the last picture: Are you a miserable old bastard?

[jdubbs32584]

I like the book in the background of the last picture: Are you a miserable old bastard?

only when i'm not around. 

ETA:

wait, maybe that should be: just when I'm around. 

[JohnnyDucati]

I'm thinking of attempting to make myself a titanium bladed, carbon fibered handled knife.

Anyone have any knowledge about metal casting or carbon fibering?

Is 22 years enough experience?   

[JohnnyDucati]

Titanium is notoriously difficult to work with.  You won't be casting it at home, nor even in any "normal" casting facility.  Ti requires significantly higher temps than steel.

Ti is easy to work with given the proper knowledge and equipment. 

True - you can't cast it at home unless you have a vacuum chamber furnace.  They only run about $1.5 to $3.0M, depending on if you have the vacuum pumps.

Also, you'd want to use forged billet Ti, anyway, not cast, for better blade properties (grain size, etc).  If you go with cast material, you will need it to be Hot Isostatically Pressed (HiP'ed) to eliminate any possible inherent porosity.  Or, likely not, because that is a very expensive process with only a handful of locations in the free world that perform that process.

Ti melts at only 100 or 150 degrees F more than steel.  That's not a significant amount, and that's not the problem, though.  Besides being unable to super-heat during the melt phase (due to having the same liquidus and solidus point), the primary challenge with molten titanium is that it is extremely reactive (think of raw sodium in water) and reacts with everything it comes in contact with, including the melt crucible.

Ti is also ugly easyto machine for those that know how.  Some shops that don't know how to do itwon't even touch it.

If your heart is set on a Ti blade, I'd be trying to find a chunk of Titanium that very nearly resembles the desired final shape.  You will need high grade grinding media and equipment and dust control because you or your children do not want to breathe the waste dust.

If you want something you can work yourself, you'll need to stick to a softer metal.  I would second this comment.

CF is significantly easier to deal with.  Pick up a copy of the Aircraft Spruce catalog, and check out the available composite cloths that are available.  Unless you've got an autoclave, or an oven you don't care about, don't bother with pre-preg (which is fiber cloth pre-impregnated with resin).  Get plain cloth, then you'll need an appropriate resin.  You'll have to determine what material properties you're looking for (fast set, slow set, very hard but brittle, medium hardness with a little give, soft with lots of flexibility, etc).  I'd imagine in a knife handle that you want something with a little give to it, so it doesn't shatter the first time it gets dropped on a hard floor.

We can easily wrap a knife handle with CF fabric and resin.  We could probably even get creative and vacuum-bag it (reduces air bubbles, resulting in a better looking and stronger finished product).  The biggest challenge will be creating the knife blade, and as I said earlier: if'n you want a Ti blade, you'll need to find it pretty much finished, because there's no way for us mere mortals to work Titanium in the average garage.  Well said.

Actually, you can have your cake and eat it, too, in this case.  In fact, you can cut your cake with a Titanium COATED knife (with a steel blade).  Make your knife out of typical steel and then have it coated with titanium nitride.  Any number of vendors out there that do that.

Or, just buy one of the 'ucking things off the shelf.  I have a Gerber with Ti-nitride coated blade.  There you go.  Save yourself a lot of time, money, hassle, and carcinogenic contamination.   

Best regards,

JohnnyD

[SaltLick]

good lord man just go down to Kmart and buy a pocket knife.

[duc_fan]

Apparently Johnny D has had a different experience with Ti than my other machinist friends and aeronautics material science professors.  Having the right tools makes all the difference.  It's probable the other folks I know didn't have the right tools for working with Titanium.

My info is from friends.  Johnny's is from working with it himself.  This is a no brainer.

We still don't want to mess with it in the average garage. 

I like JD's idea of making the blade of steel then having it Ti-nitrided. 

[JohnnyDucati]

Apparently Johnny D has had a different experience with Ti than my other machinist friends and aeronautics material science professors Those that can, do.  Those that can't, teach. .  Having the right tools makes all the difference.  It's probable the other folks I know didn't have the right tools for working with Titanium.

My info is from friends.  Johnny's is from working with it himself.  This is a no brainer.

We still don't want to mess with it in the average garage.    Right on.

I like JD's idea of making the blade of steel then having it Ti-nitrided. 

[NEIKOS]

Well shit . . . another shattered dream.

[ryandalling]

Well shit . . . another shattered dream.

Is that like the one where you wake up and are six foot tall?

I have a dream where i wake up and I am a nice guy and people like me. Unfortunately, I think I have perfected the art of being a bastard. 

[marvellous]

You'll 'cut' your eye out kid...