Kitchen knife help???

weo

weo

Joined
Sep 21, 2014
Messages
3,117
Hello all. A problem and 2 questions about my most recent kitchen knives.

On my most recent knives, after finishing them, I was flexing the blade a bit (not sure why) and heard a 'pop' that was the handle epoxy failing allowing the front part of the handle to break free from the neck. The handle didn't break, it's just that as the blade flexes you can see a small space when holding the knife up to the light. I feel that this shouldn't effect the overall performance of the blade, but is an area where food gunk or water could get trapped in causing the blade to rust.

My questions: 1. Is there a fix for this other than removing the scales and replacing?
2. Is the fact that I polished these to a near mirror finish up to 2000 grit the cause of the epoxy failing? (I currently and using Bladebond).
Thanks
~billyO
 
Was the area the scales are on also mirror polished? If that is so, then I would say that definitely had something to do with it.
 
Josh Rider said:
Was the area the scales are on also mirror polished? If that is so, then I would say that definitely had something to do with it.
Click to expand...
Yep, that was my fault. An experienced friend says she only goes to 800 at the highest.
Is there a recommended high/low finish to go to on kitchen knives (especially related to this epoxy problem)? Or is there a recommended epoxy that will hold at higher grit finishes?
 
I polish back a bit from the ricasso, but once the scales are fit up I'll trace on the outline of the front, and scuff almost right to the line with scotchbright. I've never had an issue.
I use loctite ea-120hp for everything, I've tried half a dozen epoxies and this is the only one I'd constantly have the wood fail before the glue joint. If it somehow became unavailable I'd buy one of the 3M aerospace epoxies.
Gflex and others are very good as well, but this is just a little extra peace of mind for me
 
I go to an extreme. Once I am ready to fit/epoxy the scales onto the tang, I"ll draw file the tang to some extent, not enough to change the geometry of the tang at all, just enough to scuff the surface. Then grind in a shallow "well" to allow an epoxy "reservoir", like many here do and recommend. Also the bottom of the scales are usually at 80-120 grit, also with epoxy "reservoir" holes drilled in.
 
Leave the blade and scales at about 120 grit. I believe G-flex is the best epoxy because it allows for a small amount of give in the glue joint. Most regular epoxys form a rigid glue joint so when the blade steel and the scales expand and contract at different rates due to temperature changes, the joint can fail.
 
I usually scrub a few times with dawn and water, then denatured alcohol followed by scotchbrite to rough up the steel where the scales will be attached. I do the same to the backs of phenolic and laminates. With wood I just leave around 120 or 220.
 
To fix the existing problem, run medium CA in the gap. Flex the blade a bit a few times to promote it wicking back. DO NOT CLAMP. Set it down and let the resin cure for 24 hours before cleaning of any exces.
 
weo said:
Yep, that was my fault. An experienced friend says she only goes to 800 at the highest.
Click to expand...

If you are meaning 800 grit where the scales go that's still way way way to fine of a grit to try and epoxy something to.
 
I have to agree with Stacy on this one more or less. I'll scuff the tang at least at 220, or even 120. I then score the scales with an exacto blade. But I am usually using very hard woods like ironwood, so the bite of the blade isn't too deep, and I keep it away from the edge a bit.
Brownell's Acraglas epoxy for me.

If it isn't a keeper for personal use, I'd start again. Whatever you do to patch it is going to fail before too long.
 
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