Jim L.

I believe it is correct to say "distal taper" as its a reference from end to middle. Very nice knife IMHO. 

On 4/19/2019 at 12:40 PM, JHCC said:

Why would one say such a thing?

I honestly don't recall who said that about not changing the sanding direction. Some how the scratches come right out with decreasing grits and a nice sanding block.

Some people say "never, ever, ever change directions when sanding". I subscribe to the camp that says " changing direction while sanding helps to find then elliminate scratches left by coarser grits."

Well done, Sir.

You are correct in that with in 99% certainty, using science [wing loading (square surface ÷ weight = weight/ in. sq.), air velocity, air foil shape (Bernoulli's laws and the venturi principle) yada, yada, yada] that "X" aircraft will fly.

I merely stated, using perception only the eye cannot explain scientific fact.

That said, feathers were not meant to be ruffled, nor undergarments bunched, much less ill-spirited and/or sarcastic comments meant to be inspired.

I can only state the fact that I have witnessed this phenomenon and admit that I cannot offer a scientific explanation as to why it occurs to my or anyone else's satisfaction. There are as stated and conceded, too many variables. My ignorance as to how it happens isn't proof, scientific or other wise that it doesn't. 

You probably have a point. 

If you flap your arms real hard, chances are you won't feel any lift (um, it's imperceptible for many reasons). The wings of a C-5 Galaxy transport must generate excess of 500,000 pounds of lift in order to become airborne. You can not "perceive" the reasons between the results with your senses. Ergo the heavier than air craft was concieved of by an oldtimer making a joke.

Do not discount an idea on merit of perception only. No, I can't tell you the molecular properties with certainty of a particular metal at a given thermal state. I can tell you that occurrence of warpage is greatly reduced using near identical angles in the same quench vessel and quenchant when in the northerly orientation versus 90° to that.

I believe that some folk are missing the point. It is my belief that the OP was showing that it was an interesting process, that it could be done. Not as a recommendation as a fantastic methodology for manufacture 

Very nice. Thanks for sharing.

Very true.

On 1/5/2019 at 3:08 PM, sfeile said:

I hope that was just a joke. There is no reason to point a blade to magnetic north when quenching other than maybe it is the best lighting option when heating or the way your shop set up happens to face by coincidence. There is no scientific reason that will alter the blade due to what direction it is pointed on a compass.

Sorry, nope. Not a joke. The explanation given was that ferrous metals heated to non-magnetic will seek out magnetic north as they cool. What ever the reason it seems to work. Believe it, or don't. I've had little to no warpage since beginning the practice. 

Science can explain everything, but that doesn't mean we understand what we are told.....

Well done, Sir. It should serve you well. How did you do your heat treat?

Most of tje scratches can be removed ising a sanding block a progressively finer grits of sand paper.

Have ever tried using a maul or billie club instead of a hammer? The wood, being softer than metal won't ding the blade nearly as bad.

If it bends during normalizing there may still be stress in the steel. My experience has been to normalize again if I have to give the steel another whack.

I've seen the 3 pin method done on just hardened blades and it makes me grit my teeth. The maul comes in handy where you have a few seconds for a sraightening whack without stressing the steel too much.

That is a shame anout the break. It looks.to jabe had a nice profile.

The profile could be reground as an interesting skinner in an effort to save it.

I would recomend that you bring the blade to near finish grind and sanding before quench.  Leave some meat on the cutting edge. This allows for better thermal retention and less chance for warpage.

This sounds like a bunch of whodoo; finf magnetic north and align the blade N/S at quench. 

A very good start, Sir.

All too true, Theo. I enjoyed your episodes very much on F&F. 

Very cool. 

@sfeile makes the point that I was trying to. The idea of the lower carbon contents is to, at least in the case of the RR spikes and poosibly the rebar is to make them more temperature tolerant.

Desert loateted rail roads must endure temps ranging from the 30's at night to 90's/100's during the day. Metal fatigue can result with less maleable steels with higher carbon contents.

Bent steel still has the potential for support where as broken won't. 

They are great for practice when free,  but not so much when you have to pay for them.

This is as I understand it and would gladly stand corrected

Forging a cutting tool from rebar is a lot like forging one from a rail road spike.

It can be done.

It can be made sharp.

Its cheap.

Edge retention will be 3-6 out of 10. If you must use rebar,  try to get scraps of the stuff used in bridges. Supposedly it has to meet higher standards because of failures.

Just a thought. 

Very interesting.  Very nice.  I especially like the idea of using the copper wire binding.  For what it's worth,  Well Done. 

Jim l.

I agree with the regrinding of the spine,  polish, then re-etch.  This will make a difinitive diagnosis of splitting layers 

Jim l.

I wonder about the new formulations that were made for bridge work?

Nice job,

Jim L.

Nice job on the forge, dude. 'Wish I had some sic welding skills. I set the air inlet port at about 40 deg. Incidence to the tuyere on my forge. I can then inject air from a low pressure/high volume compressor. Variable flow is achieved using a venturi at the port. Ash and the heavier chunks drop right through the open tuyere into a bucket of water.

As far as fuel is concerned, what's wrong with charcoal? If your willing to drive 90 mins. for coal, you can take the money you'd spend on gas and put it toward a couple bags of lump charcoal. That would get you started until you could (a)make your own, or (b) find yourself in an area where you could get some coal with out making a special trip.

Send some pics when you get'er fired up!

Jim L.

Are you talking SAWMILL type bandsaw blades or metal cutting bandsaw blades. The sawmill bandsaw blades available to us here in the Northwest are wonderful stock for knives. OOPS-Sorry. I just re-read your post and you did specify metal cutting blades. Anyway-the sawmill blades are pretty easy to come by here if anybody needs me to snoop around and get some chunks.

What if the spike head is stamped "1" over a symbol that looks like the letter "B" laying on it's back,, and under that , "MC"?

There were a few of those mixed in with a metric butt-load of the "CU"'s I found abandoned in a shallow grave near some tracks.