Today was a good day. I got a lot done on the batch knives and some work done on some Journey Smith qualification knives as well. First my little bending jig didn't do as good a job as I had hope. 15 out of 20 knives actually had to be heated up and bent straight again.
waiting for the forge to warm up.
The first to be straightened on the anvil. Basically you just heat it up and set on the flat anvil surface and strike the high sides. Not a lot to show here. Some only took a few whacks. Some had me about ready to throw the whole batch in the trash.
Now time to forge a bowie blade out of 5160 or leaf spring steel.
First I forge my point. The angled side is going to be the top clip of a bowie knife.
Then I forge where the blade edge will start and start to bring it down.
Then I bend the entire blade over like a hawk bill. As I forge the blade edge down the spine will come back up. If I don't bend it down now then it will end up looking like a banana. That is ok if I intend to forge like that. But I prefer this method so I don't have to hammer on the edge to bring the spine back flat.
Now here is a trick I learned from MS Tim Hancock. If you don't have a power or trip hammer to make forging the edge down easier on you but do have a hydraulic press, you can make yourself and angled flatter. It's just a piece of 4" channel that has been cut off and the side welded to a piece of scrap. Place the edge between the press dies with this on top and you can forge an entire bowie blade edge in only a few heats instead of 20 or 30 minutes it would normally take me.
Two heats later and using the flatter on both sides the edge has been drawn down and the spine has straightened itself for me.
Another trick from Mr. Hancock was this little device. It allows me to put the blade into edge down and make sure my edge is centered and not off to one side or the other. I have another one that has a channel in it that will hold the tang of the knife for me, in case I need both hands free.
I started to draw out the tang when my propane started to freeze up on me. So this will have to be it for the day. I usually like to finish the blade more but I ran out of time. My little bottles of propane freeze up after about 2 hours of use. Flattening the batch knives took longer than I thought they would and ran out of time.
By this time my heat treating furnace was up to temp so I put in the batch blades to be stress relieved.
The blades are at 1200 degrees for one hour to relieve any stress and hopefully ensure their will be no further bending.
Now it was time to grind some JS selection blades. I set my grinder up to 45 degrees and grind a bevel to my scribed lines. If I didn't do this the 90 degree edge would strip the abrasive off my belt quickly.
To protect my lungs I use a air pro trend shield. It's a face mask with a motorized filter to protect my lungs and eyes.
The first bevel
Then I max out my work rest to about 65 degrees.
One of my other machines is already set up for regular hollow grinding and I adjust the height to hollow out just above the previous grind. That will give me three angles and a tripod affect when I put it on the flat platen giving support for the correct angle to flat grind it.
All three bevels.
And the flat platen. This one has a tempered glass glued to the metal platen to keep the friction from easily hollowing out a grove in my platen. It will eventually happen even with the glass but not as fast.
And that sets up this flat grind, ground in about 4 or 5 passes.
But that is not flat enough. So it's off to the precission ground disc sander.
This disc sander has a 1 degree bevel allowing the tip of the blade to extend past the center of the disc.
Now the flats are good an flat. They will still be sanded on the surface plate before it is good enough. But if I did it right on the disc sander that usually only takes about 10 minutes tops.
The set of JS application blades I worked on today.
I like Aldo's steel. He took care of everyone that got a bad batch. How many other steel suppliers would do that? The 52100 in this batch is from Aldo as we'll. so long as his service is the same I will use Aldo when possible. Are you a knife maker too? I'm in the shop now. All knife makers have an open invitation here.
Well I got a phone call from several people this morning saying they were coming by. So I didn't really do much this morning except clean up the shop and rearrange the forging area to resemble the plan I submitted to the building inspectors.
This treadle hammer is no fun to move. It has a 4" solid metal anvil that makes it awkward to move around with all the weight on one side. Very easy to tip over. If anyone knows anyone looking for a treadle hammer I have one I would gladly let them have to get it out of my way to make room for the power hammer.
Then I had to make a new mounting bracket and get the post vise set up.
After about 1130 I gave up waiting on the inspectors. I guess the conversation on the phone was good enough for them. Who knows maybe they got busy and will show up tomorrow.
So I got a few more blades surface ground and prepped for flat grinding.
Chuck from Alpha Knife Supply stopped by the shop the other day. Apparently he was taking the class with Rifle Dynamics. Saw my shop and stopped in for a bit. He gave me some advise on how he straightens warped blanks. So tomorrow i'll give that a shot.
Well most of the progress for the rest of the week is going to be boring, so I won't post much. I had to go and buy new welding leads, welding gear, etc.. The new leads were no joke and had an eye watering price tag attached to them.
I picked up a new metabo grinder.
I used them in the navy and they are real workhorses. They have a clutch so you can easily take the grinding wheel off and on and keep moving. I told the guy at airgas we used them in the navy. I found out he was an HT as well and we were in some of the same commands together, but never ran into each other.
I have arbor presses but stepped up to a 2 ton press to help straighten the blanks.
This worked a lot better than my little bending jig. It has a lot more force.
I got my old post vise set up. This thing is several hundred years old and will still work for several hundred more.
The rest of the day was spent stress relieving the blanks and straightening them on the arbor press. All the blanks are now nice and flat. I reground the profile. I have ten more to regrind in the morning then it's off to surface grind the lot.
I have more errands to do in the morning tomorrow. Then I will spend most of the day at the grinding station. On some good news I finally passed at the inspections for the fire inspector and got my business license today.
Yeah Travis has built a magnetic sine table into his surface grinding attachment. It makes tapering tangs a breeze, as well as allowing you to surface grind on your grinder. He makes it for his TW90 grinders and the KMG grinder from Beaumont Metal Works.
He is constantly upgrading and coming up with new things for his grinders. He now has a similar surface grinding attachment that after you surface grind the flats it will actually allow you to angle the flat platen and flat grind two knives at the same time. It's still in the prototype phase but knowing Travis's work when it is done it will be a great addition to my shop.
First I had to head out to Airgas first thing this morning and pick up my new leads and welding accessories that arrived Friday.
Then back to the shop for more grinding. After the initial bevel the 65 degree bevel is put that put a shallow hallow grind in the blade. Using that as an angle guide I then move to the flat platen and make my flat grind.
Once I got a bunch of those done I moved on to tapering the tangs. This is done with the magnetic surface grinding table. Here is the rollers the sine table slides on.
Then the magnetic sine table just rolls on those.
Now this really makes this a cool attachment. Loosening the 3/4" table bolts.
I can use either pin gauges or a cheaper alternative feeler gauges. Since I have done so many of these already I already know what sizes I need to get the required angle.
Here you can see how the table is no angled to give me the proper degree angle to taper my tang from the butt to the grind plunge lines of these knives.
Here you can see how the first flat has been angled in only a few minutes.
Now it is time to grind the other side. Since this is a sine table if I use the exact same feeler gauges on the 3" angle adjustment it will be exactly double the angle of the previous grind. That accounts for the metal already removed to give each side the exact same angle.
A few more minutes at the grinder and now both sides of the handle are angled exactly the same starting at the plunge line and ending at the butt of the handle.
All in all I ground a lot of blades today. I have a lot to grind before the week is through. I am only getting a few hours work out of my dust collection system before it is so clogged that it is useless. I'll have to redesign it in the future when I have time.