Recommendation? Thin blade. Lateral stress. "Click"

M

Maelstrom78

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Sep 21, 2013
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So yep on a 7"ish blade .070 chef knife There was some lateral stress drying it off and I felt the "click". So the epoxy pulled from the front of the knife. I have a pin close to the front and I am not worried about failure or anything but the fact it exists bothers me.

The pin didn't pull or anything. That .070 with distal taper slices like a dream but there is lateral flex.

From now on I am contemplating putting in a hidden pin that will sit right at the front of the scales just to avoid that. Or I guess peening on a metal bolster for all of them but that kind of blows.

Either way I think I have to wick in a tiny bit of CA glue or something for my mental health. It's sitting there right now in it's block..... not sealed.....it's AEB-L so it doesn't matter...but it does!

Here is the blade.

MbgpBoO.jpg
 
The other issue is there is likely NO epoxy under the scae. If the scales and the tang were both sanded flat and you clamped them tight together in glue-up ... all the epoxy was squeezed out. You need to recess the scales and/or tang leaving only a perimeter lip to seat flat. This creates a glue reservoir that holds much tighter. Using a flexible resin is also wise ... G-flex is very good.

On larger bladesm drilling lots of 1/8" holes all over the tang works well. We call this a swiss cheese tang.

For this knife flow some CA in the joint to seal it up. There are also flex-CA glues.
 
Well it was scuffed with a 60 grit and I did use G-Flex. Hmm I did not recess the tang, however. I will start doing that . Maybe I will do that AND a hidden pin.

Since it was so thin I didn't drill the myriad of holes I typically do. Hmm so multiple potential things to improve upon!

I do happen to have some super thin "flexible" CA on hand to use.

Thanks all.
 
Yes, the "glue starved joint" is something few people think about .... until they start making thin blades. This Is another reason I like Corby bolts. No clamping and you can get just enough tightening on the scales. Since I started using Corby bolts and relieving the handle underside, I have never had a scale pop loose. I have also had only a few crack or break in use, too.

I meant to ask, Is that dyed box elder burl or dyed buckeye burl? Either way, it is really pretty.
 
Hmm well you are right on that one. I have never ever had an issue until now. I really dig the .070 so I will be using more tools in the toolbox. Truth be told the biggest "gap" I can get flexing the blade to the side is miniscule and noone but me would ever know it's there.

Even so I am going to flexible CA it.

It is actually a black ash burl and it is pretty striking thanks!

UsMzR1o.jpg
 
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Stacy E. Apelt - Bladesmith said:
The other issue is there is likely NO epoxy under the scae. If the scales and the tang were both sanded flat and you clamped them tight together in glue-up ... all the epoxy was squeezed out. You need to recess the scales and/or tang leaving only a perimeter lip to seat flat. This creates a glue reservoir that holds much tighter. Using a flexible resin is also wise ... G-flex is very good.

On larger bladesm drilling lots of 1/8" holes all over the tang works well. We call this a swiss cheese tang.

For this knife flow some CA in the joint to seal it up. There are also flex-CA glues.
Click to expand...
If pin was metal and pinned this would not happen , even if he don t use epoxy at all , right ? IF I ever make this kind of knife I will use polyurethane glue ......

https://www.christinedemerchant.com/adhesive-glue-polyurethane.html

You can make some test with this Gorila glue ..and decide which is better for this application

https://en.wikipedia.org/wiki/Gorilla_Glue
 
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One more thing , sandpaper don t make good surface in steel for epoxy .I use Dremel for that ...................
5nrJZ5z.jpg
 
Another thing that works well for recessing the tang is the corner of a small diameter wheel on the grinder. Because I can be anal about some things, on my full tang knives, I swiss cheese the tang AND recess both the tang and the scales, And use corby bolts. As they say, better to have it and not need it than not have it and need it....
 
mknife said:
you can do a much better job using belt grinders. You can do something like this (it's just an example) with 40 grit belt:
tang1.jpg
Click to expand...
Of course ....But I would really like to see how you would do that in .070 thick steel :)
 
Thanks guys. It's an example of me being complacent as I have done all of those in the past and have never had an issue so I just got away from doing all of them on every knife. I have it sealed up now and you can't tell there was ever a tiny gap but lesson learned.
 
Natlek said:
Of course ....But I would really like to see how you would do that in .070 thick steel :)
Click to expand...

Just be careful and make sure you keep each sides depression less than .035" deep. The purpose of doing this is merely to allow the epoxy to squish throughout the whole tang, making one big thing of epoxy holding the scales together instead of multiple little holes holding the scales together.
 
You can also buy a very fine filler from West Systems which prevents you from squeezing all the epoxy out of the joint. The filler acts like a very thin layer of marbles which holds the tang and scale apart with all the gaps filled with epoxy. It will give you a glue joint which is perhaps .001" thick - too thin to see.
 
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