Practice knife #4 WIP

Atlas Knife Company

Atlas Knife Company

Joined
Feb 16, 2010
Messages
3,668
People say to practice, practice, practice. Enough of it can even make perfect. Still a LOOOOOONG way from perfect, but I am learning a lot as I go. Today I learned low quality belts can cause problems and how to rework a nicked blade in the finishing process. I learned just how thin band saw belts are, and how hard they are.

I need to learn how to take the gentle bend out of a band saw blade. I also plan on learning how to put a lanyard tube in the handle. I also plan to learn how to work with Solid Surface on this practice knife(getting OK with oak, time to try something different).


Beginning band saw segment, no heat work of any kind performed
4practice1.jpg


Sorry, Pic 2 had the lens cap on. It was a pic of the metal after cutting with tin snips(very hard to do on non-annealed metal) I did temper the blade for 15 minutes at 400. Now it will cut, before that it would break with the tin snips.


Profiled, belt sanded 50, 60, 120, random orbital sanded 80 and 220. A little work at the tip.
4practice3.jpg


Random orbital sanded 220, 400, 600, hand sanded at 400 then buffed until a static zap caused me to drop it. While falling it got caught and nicked the blade.
4practice4.jpg


A thought occurred that I could grind off the bottom 1/16" of the edge, also a little work at the tip.
4practice5.jpg


Currently buffed to a mirror finish. Can still see swirls from the random orbital after buffing. I couldn't see them before buffing. Also, there are several stray scratches from the cheap 50 grit belt that I can't get out. Well, I could get them out but there would be nothing of the blade left. It's .032" thick and that doesn't leave much for hogging. A little more buffing on this side before I bead blast the blade.
4practice6.jpg


A practice knife means it's for practice. I don't plan on heat treating the blade, since it's still pretty hard and I quench a lot during grinding. This knife won't be used to fight bears or even fillet fish. It may be used to cut sandwiches in half.

I am going to order some green zirconia belts at 60, 120, and 240 grit. Any comments about these belts would be helpful.
 
Disaster in the handle! Maybe I need to use corby bolts instead? The 105/207 epoxy didn't seem to stick too well to the solid surface or the steel. It set up fine in the mixing cup, so I don't think it was a bad batch. Any ideas?
4practice7.jpg
 
From my limited experience thus far, it looks as if you drilled the holes for the pins a bit too big...which is causing the 'ring' of epoxy on the pins. Is that what you are referring to?
 
did you rough up the surface of the tang to give the epoxy something to grab too? When ever I have something go wrong I always go back and double check the little things that I may have missed and usually find the problem
 
If you said "YES" to Wade's question, then that is your problem. The clamp pressure should not be strong, only enough to hold the scales in place. If you squeeze the scales against the blade hard, you will squeeze out all the epoxy.
The epoxy isn't to hold the scales in place anyway. It is there to seal the handle/tang joint. Use Corby, or similar bolt type rivets, and you will never have problems with your scales coming off.

The deep scratches are there because you did not sand them out at the next grit. Don't go to a higher grit until all previous scratches are gone. Unless you are content to have a poor finish, save the random orbit sander for woodworking. Blade finishing is all about sanding control, not about blending in.
 
Yes, Stacy, I did probably use too many clamps(6). Should I go back to rubber bands? I seemed to have better luck with them. I think I will go back to the 120 grit by hand until I get the scratches out.
 
The first and last rivets are too far from the end of the handle.
If your careful you could trim the front one then add a hollow pin at the butt end, then get some dust from the handle material into the remaining gaps and add a bit of super glue.
Richard
 
Ah, good catch on the pins, they are a tad distant from the ends. However, I just hammered out the pins and removed the scales. The thinner scale is now warped(bowed). With one end flat to a table, the other end sticks up about 1/8". The odd part, it's the factory finished side that I hit with the 220 grit. It was perfectly flat prior to gluing. Anyone have ideas as to why a piece of solid sorface would bow like that?
 
I hesitate saying anything in threads like this because I have so little experience myself, but in this case I'll step out onto the ledge a bit, if for no other reason than to hear what others think of my ideas.

My personal preference is for pins to be tight in the wood. Not so tight they cause a crack. but tight enough so there is a real problem if you have to knock them out. I have to pound them in pretty good to get them all the way through. To do this right the holes in the tang need to be large enough for the pins to pass through, but the holes in the scales need to be a tiny bit smaller (say 1/32 smaller) than the pin. It helps to have a digital micrometer to measure things correctly.

I also like to play with offsets a little to make sure the pins firmly seat with the tang. I do this by drilling the holes in the wood first. Then I seat the tang and use the same drill be to mark the tang. I switch to the larger bit, then drilled slightly off the mark point to force the pin to put pressure on one side of the hole or the other. If working with a block handle I'd drill the holes offest toward the blade by, say 1/16 inch, causing the pin to hit the back side of the hole and pulling the blade taut against the handle. Worked like a charm on my first handle, and that friction is all that is holding the handle and the guard in place.

Here's a picture illustrating what I'm talking about:
PinFittingBlock.jpg


I haven't tried the method for scales yet, but if I did this is how I'd go about it. I'd use opposing pressure on the pins... one offset toward the blade, one offset toward the butt. If you have one or more pins in the middle, you might consider offsetting those toward top and/or bottom of the tang.

PinFittingScales.jpg


The result is pins that have zero gaps in the handle (no gaps for glue to squeeze through) and are strong and tight.

I've never tried the corby pins yet. I may try those next, as that seems a lot easier than the way I just described... but somehow I took some pride in making things work in my typical low tech style.

- Greg
 
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Oh boy, do I feel stupid. I hope Stacy let's me live this one down some day! After I drilled out the tang holes, I didn't re-grind around them. Thus, the scales didn't fit flush against the tang. Also, the solid surface can bend warp when warmed. Not a lot, but enough to stress the epoxy and break loose.

Tryppyr: I would advise against the method you propose for your pins. Anywhere it is that tight on the pins could cause cracks or even cause the wood to split. I considered, on a 1/8" pin, drill a 17/64th hole in the tang-side of the scale just a little shorter than the depth of the final handle. This would give a flush fit on the outside of the handle, but enough room inside to fit epoxy around the pins.

It's a good thing I have 2 square feet of this solid surface to play with.
 
Yep, check the holes and tang before gluing it up. Tang holes should be slightly oversize and countersunk.
Things that were flat as a block often warp when ground into handle shapes. Also, cutting a block into scales can sometimes create a twisted piece of wood. Both the heat as well as the stresses released ( and created) but the shearing of the wood grain can cause flat scales to curl at the ends, or twist. Go slower and avoid heat build-up.

Tryppyr; I agree with Zaph, trying to make an overly snug fit replace a proper fit isn't the way to go.

The only way to assure that the pins will hold against warp, swelling, shrinking, etc., is to have the pins/rivets peened....or use bolts. Loveless, Corby, Acorn, and a few others bolt types work superbly. A slightly cheaper, but less strong option is cutler's rivets. They have to be installed right or they create more splitting problem than they cure. If making a constantly reproduced handle, like production runs of steak knives, then they are a viable option, but for the few dollars that handle bolts cost on a custom knife, you will be far to the better to use them.

If I haven't made myself clear on this subject y now, let me rephrase my response_
My advise is to USE CORBY (or similar) BOLTS .
 
Just curious, Stacy, why don't you like pins?

Yes, the solid surface, which is essentially an acrylic sheet, definitely warped. It looks as if that was the biggest problem before. It took me 15 minutes just to get it flat again. Do you put the corby bolts in when you glue or after it has cured?

My kitchen knife project is delayed until I either get a band saw or DM Steel get's their plasma cutter fixed. The replacement torch is on back order and I have about 15 pieces I need to cut. Although at this rate, I may be contacting Amarillo water jet. . . .
bladsmth said:
Things that were flat as a block often warp when ground into handle shapes.
Click to expand...
 
Corby bolts are put in when the handle is glued up. They provide all the clamping needed, so no clamps are used.
Turn them just snug enough to pull the scales down on the tang. Don't over torque them or they may lift the ends of the scales.

As to why I prefer bolts ( specifically Corby bolts).......
Take a board and pin it to a platform that hangs over an alligator pit. Now take an identical board and bolt it to the platform.....which one will you be willing to walk out on????

Pins are just glued in place . If you could push it in, it can slip out. If the fit is very tight, virtually no glue is between the hole wall and the pin, so any minor force can easily raise up the scale. If using pins ,the hole should allow a smooth in and out fit to the pin so some glue gets in between the joint. The pin should be held in a drill and rotated against a piece of 100 grit paper first,BTW. If using pins, use structural epoxy, like T-88 or acraglass. Or....use Corby bolts.
 
Good point about the pins and alligators. I never read about roughing up the pins, but I did it anyway figuring it would help.

Well, the gluing went much better this time. I made sure the scales were as flat as I could get them. I also added several 1/8" holes to the tang for epoxy to go through and used a large (thing) at the end of the handle. It's (kinda) similar to a bolt but is hollow. It should serve the same purpose and was chosen by the friend who is getting this knife(and a 3 lb fish to fillet with it).

This solid surface is a pain to finish. The sales-rep recommended the following:

Tools Required
* Random Orbital Sander
* Micro-Mesh Aluminum Oxide Discs
(Discs are available in any size, hole pattern and backing)

Finishing Step Guidelines
Deep Scratch Removal: 300 AO
Matte Finish: 300 AO, 600 AO
Satin Finish: 300 AO, 600 AO, 800 AO, 1500 AO
Gloss Finish: 300 AO, 600 AO, 800 AO, 1500 AO, 2400 AO, 4000 AO
High Gloss Finish: 300 AO, 600 AO, 800 AO, 1500 AO, 2400 AO, 4000 AO, 12000 AO

I have sanded a bit by hand so far but it is slow going, being acrylic, and clogs the sand paper very quickly. More pics tomorrow, hopefully.
4practice8.jpg
 
Even worse disaster! The scale on the handle snapped in two! I was just finishing up with the 400 grit and was testing the flex of the blade when SNAP! Maybe Corian isn't the best handle material for a fillet knife. . . .This is the second set of scales to snap with this knife. The last set snapped when I took the pins out. I think I might use oak on this knife at this point.

I did just get the blade back from the bead blaster. I LOVE the way it turned out, nice and frosted looking.

4practice9.jpg
 
I've just started looking into making my own knives. It seems like you've learned a lot, and overall that is a good looking knife, good job.
 
I would say that Corian could be used safely on a knife with some thickness to the tang. A thin blade filet knife has too much flex in the metal. When you were testing the flex of the blade the apex point of the flex must have been right under where it snapped.

The only thing I can think of that would fix that (and I am no maker) would be to make the blade thickness at the spine thinner than the tang. Have the step down in thickness happen just forward of the handle. That way, when it flexes, it flexes at the point where the 2 thicknesses meet.

Anyone care to comment on that? Or am I talking out of my rear here ;)
 
Are you using corian cause you got a sample for free, and you are trying to stay within a budget? If you are strapped I can send you a piece of G11 long enough for several projects for free as long as you do not mind light green. you like 3/8 thick or 1/4. The G11 will not break under hard use.

If you are not into the corbys cause all of the ones you see are 1/4 or bigger, they do make smaller corbys. usaknifemaker's has corbys that are stainless with a .120 shoulder (a hair under 1/8) and another with a .185 shoulder (a hair under 3/16). However, with the micro you need to look at the shaft length to make sure they are long enough so you still get enough meat on the scale material behind the shoulder. Also, buy a drill bit that matches the exact dimms of whatever pin or bolt you intend to use. Lately I have been going to the tool store to buy more number, letter, and in between metric drill bits for my folder project. But, that's what I need to get the exact dimms I need for it to work properly (hopefully). They sell the right size drill bits right there so get em when you get the corbys.

Lemme know if you want the G11.
 
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