factory made knife engraving prep?

[ken dixon]

Hi, I read Ray Covers tips on engraving custom knives, the only part I did not understand was about the blade needing to be open for engraving. I am not implying that is not right, I am not a knife guru by any means. I just wondered what was different with it open vs.closed? And the main part of my question is if this applies to the factory built spyderco and al mar knives?

Thanks Ken

 

[Ray Cover]

Ken,

If you leave the blade open it does a few things for you.

1. It allows you to mummify the blade in tape to protect it.

2. It allows you to close off the inside of the folder to keep grit, chips and dirt out. Stuffing the cavity with tissue paper is usually the best way.

3. IF doing inlay having the blade out allows you to shim the knife to prevent the scales from drawing together on the pins and seizing up the knife or making the action sluggish.

4. IF you do seize the knife up or get dirt in the mechanism, the freeing up and cleaning up process is easier started with the blade open.


Here is a worse case scenario with the blade closed.

You take the knife with the blade closed and using a "knife fixture" or some thermal lock or just leather padded jaws clamp on the knife in the vise. You engrave and gold inlay the design on the knife.

Now its time to tkae the knife out of the vise.

The first thing you notice is that the blade won't open because the gold inlay process has drawn the pins tighter and over tensioned the blade and blade contact surface (proper shims prevent this. Proper shimming cannot be done with the blade closed).

Now since the blade is stuck in the closed position you have no real leverage to try to get it moving to free it back up. So you get your self a piece of leather and a pair of pliers and start very carefully pulling on the exposed back of the knife. It starts to wiggle. After fooling with it for about 20 minutes you finally get the blade out enough that you can grab the end of it with your fingers and you finally have enough leverage to start working it by hand.

However, now that you have the end of the blade sticking out you notice the very tip of the blade has a flat spot on it where the very edge of the tip has broken off. You ask yourself,"whats this about?" and you look inside the pocket to see a nick on the polished underside of the lock spring where the clamping pressure from the vise drove the point of the blade into the underside of the lock spring.

Continuing to work the knife open, an hour later you are now getting the knife so that it will open and close but it has a gritty feel to its movement caused by stoning grit that was flowed into the mechanism by your stoning oil when flushing the inlay.

You take some very thin oil (or if your lucky enough to have one a pressure parts washer) and start washing the mechanism out to rinse out the grit. After about 45 minutes to two hours (depending on how dirty it was) you finally get the grit out and the gritty feel is no longer there.

But now you notice a drag spot in the action. Remember that clamping force that drove the point of the blade into the spring? that same clamping force has pressed a flat spot on the inside and outside of the oilite bronze bushing that the blade pivots on. It has also bent the pivot pin about a half thousands making the blade slightly tighter when its closed than it is when its open (not a lot but enough to notice).

Now that your already sick and thinking Oh Crap! you look at the Rados Turkish Damascus blade and notice several stray scuffs and scratches going against the pattern of the Damascus steel. These scuffs and scratches are caused by small chips and grit that got between the closed blade and the pocket housing while you were cutting. They are very small and lite scuffs but on that fine pattern Damascus they stick out like a sore thumb.

What I just described was the knife engraver's nightmare and this would be a very worse case scenario. That being said, any and all of these problems can be caused by engraving a folding knife with the blade closed. You may get lucky 99 times and get away with it just fine. But watch out for #100. Sooner or later engraving a knife with the blade closed is going to cause real headaches.

Honestly, I would treat any knife properly factory or handmade. If it is a good enough quality knife to spend your time on its a good enough quality knife to take care of.

PS. don't ask how I learned all this.

Ray

 

[ken dixon]

Ray,
Thanks for taking the time to answer, I understand completely now

Thanks Ken

 

[Tira]

Thanks for the explanation Ray. I've moved this question and answer into the Tips archive added to the first post about your checklist so the info is all together.

 

[Mike Cirelli]

Ray you must have engraved a few knives
Good answer.

 

[filbertius]

Judging by Ray's answer, I'd guess at least a hundred...
Good thread, btw.
Gary

 

[Ray Cover]

Ya I've engraved a few. Knives have been my bread and butter for close to 20 years now. Dang that makes me feel old.

Ray

 

[Sam]

I'll add a few more thoughts about knife engraving.

1.) I've always engraved knives with the blades open because of the holding fixtures I make, which don't allow for closed blades. However, I have heard of engravers engraving them in the closed position.

2.) I used to go to great trouble to make custom shims to prevent the knives from tightening during engraving and inlay. I eventually abandoned this because it didn't seem to make much difference.

3.) If you do shim the inside of a fine knife, be aware that many custom knives are finished to perfection inside and out, and dragging a tight fitting shim back out of a knife can scuff the insides. If you've stoned gold you'll get some abrasive inside no matter how careful you are, so try to clean well before removing shims.

4.) I made a brass lever tool that I used for shim removal since once they're deep inside they can be very tricky to remove. Again, be extremely careful and don't scratch the insides of the knife.

5.) I stuff the insides of the knife with paper towel and then seal the opening with electrical tape and trim to fit with a scalpel. This is not a 100% seal, but it helps to keep the insides clean. I also pack a bit of transfer wax around the blade where it exits the front of the frame. This helps to seal that area.

6.) some custom knives are relieved where the blade pivots in the frame. This is a godsend and keeps the ricasso from getting scratched during opening and closing.

7.) When I'm finished with a knife, I remove the tape and paper towel inside and flush it with lighter fluid. I try to get it as clean as possible before working the action.

8.) Normally the action will stiffen a bit from the engraving and hammering. I'll apply some light oil and gradually work the action. If it's still tight, I'll squirt some green Lux dishwashing liquid inside and work it under running water (a trick I got from knifemaker Joe Kious). The action should get better after this, and I blow it dry and give it a drop of oil. If it's still tight, send it back to the maker for tweaking (they have special adjustment tools).

9.) Care should be taken to make holding fixtures that fit the contour of the knife. You can't just clamp knives into the vise or use pins to hold them. I use Thermo-Loc to make fixtures that fit the knife perfectly. Properly fitting holding fixtures will make the job much safer. Hold knives incorrectly and be prepared for damage.

10.) An engraved knife should leave your shop with the same finish it came with. If you're not sure about this, contact the maker and have him or her explain how they achieve their finish and then duplicate it. An exception to this might be a mirror finish. I find that engraving looks better with a satin finish as opposed to a mirror finish, and I will apply a satin finish.

11.) Engravers have gotten bad reputations over the years when dealing with custom knives. Many knives have been seriously damaged by an engraver that simply didn't know how to hold them for engraving or produce a fine finish on the metal. Engravers have also damaged the finish on stone handle materials such as jade. You CANNOT polish stone scales so don't even try. Tape them off and protect them. If you scuff one, it'll have to go back to the maker for refinishing, and you can expect your engraving to be ruined in the process since the maker cannot polish the stone without passing over the surrounding steel. Stone scales are very tricky to work around so exercise caution.

 

[alfrisillo]

Horror Story

Wow Ray! I think you could challenge Stephen King in writing horror stories. You had me sitting on the edge of my seat with your "Worst Case Senario". Sounds like you might have been there or near there....

See you in a couple of weeks.
Al

 

[Tira]

Excellent info Sam, I've moved the post into the Tips archive with the other knife info as well.