Hidden wooden rivets?

M

MArathonman

Joined
Jul 5, 2009
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I'm thinking about replacing the scales on my esee-6 using what I think of a hidden dowel method.

Drill only partially through the scales beginning from the inside surface, place fluted dowels through the rivet holes, wood glue the dowels and then epoxy the koa wood to the tang.

What do you guys think?

Thanks!
Marathonman
 
It should work very well and you can probably just use epoxy on the whole thing and skip the wood glue.
 
wood dowels might not hold up well with only 2. you might want to slightly hollow out the scales and rough up the tang so epoxy can help hold the wood in place. the cavity would keep the epoxy from squeezing all out when you put the clamps on.
 
I agree with Darrin Sanders about just using epoxy to glue everything.

I'm assuming that you intend to use the regular fluted dowels that you can get at any hardware/home improvement store. In my mind I'm asking the question, "Are they going to be strong enough?", and then my mind answers back, "They help hold boards together why wouldn't they be strong enough?" And my mind replies "Well... He's using Koa wood. It might be one of those oily woods and glue or almost any type might not adhere well to it."

So there you are. A solid debate about the issue at hand. ;-)

It's a neat idea. Maybe someone else knows if Koa has problems with epoxy or not.

- Paul Meske, Wisconsin
 
If they're going to be hidden anyway, why not use stainless steel?
 
As long as everything is hidden and the question of strength is in play, have you considered using brass or stainless steel rod? You could roughen or file grooves into these pins so the epoxy would have something to grab onto, and any worry about the wooden dowels' strength would be moot.
 
Another possibility...

If you have the ability to create your own wooden dowels (say, from the same stabilized material that forms the scales... or maybe a nice contrasting piece) then the next obvious question is do you really need to hide them? You might even consider using them as an attractive element in the handle design.

Just a thought.
 
I've been wondering for some time why not just epoxy the scales without pins at all? Rough up the tang, wash the Koa (sanded no more than with 80grit) with acetone then glue it all up. Dowels or pins should only be needed (if at all) for alignment purposes. Of course the tang needs to be completely free of any oil residue. I am not a knife maker but a professional woodworker with steel & aluminum boat yard experience. We epoxied wood & steel regularly without issues. Not saying I'm right - just wondering...
 
Ray, we use pins to increase the shear strength of the handle material/tang joint. I admit I have no experience with boats but from my competition model aircraft experience we always used metal rod and socket construction to handle shear loads where I beam construction was impractical.

I rough my material with 36x prior to cleaning for glue up. Pins have grooves filed in.
 
Search for the Glue Wars thread for lots of interesting information about using only epoxy. They pretty much all fail at one point or another. Unless the client specifies removable scales, I always use both mechanical and chemical means to keep the handle on. My favorite method is corby bolts for strength and epoxy to seal out moisture.

RayseM said:
Rough up the tang, wash the Koa (sanded no more than with 80grit) with acetone then glue it all up ... Of course the tang needs to be completely free of any oil residue...
Click to expand...

Wipe some acetone on a piece of glass and tell me how oil-free it is. Acetone is a good solvent but a lousy cleaner. I like to follow it with rubbing alcohol to be sure there's no residue.
 
I 2nd stainless or brass pins and epoxy if they are hidden anyway. Rough up all surfaces aka increasing surface area of the bond and you will be good to go.
 
It just happens that I have been gluing up door parts today with West System epoxy. Decided to experiment to teach myself what you guys are saying. Had a broken pair of scissors and so took one half, scuffed up the tang, & sandwiched it between two pieces of South American cedar, all together with epoxy. One side of my "scale" was mortised to receive the scissors tang - only goes up 1-1/2". I'll put the finished product through some severe abuse. Will the wood break apart or will the wood just pop off the metal? I guess I'll find out.

I understand the issues with resisting shearing, but I asked my question as it seems to me that if the scales will pop off or get loose they will regardless of pins. Corby bolts or screws add a true mechanical connection that obviously strengthens the entire system - I don't question that & I wouldn't want a tactical or true work knife to be made any other way. But a kitchen knife? You guys have the experience & tradition to back up your statements, that's why I figured it was worth asking the question.

As for wiping oily woods with acetone prior to using epoxy- that was how I was taught by guys who really didn't have much more experience with epoxy than I did 30 years ago. Never questioned it as I never had any failures (that I know of). The contemporary thought, as learned today from a survey of some boat building & woodworking forums & from West System's own data, is that an acetone wipe is likely to contaminate the joint rather than improve it. Recently machined wood is as clean as it gets. Don't rub your fingers over it to check it - that just adds more oil. The acetone or other solvent is also likely to pull contaminates out of your rags. Who knew? Thank you guys for indulging my intellectual curiosity. I'm smarter today as a result.:D
 
RayseM said:
I'm smarter today as a result.:D
Click to expand...

Me too! :)

I should have mentioned, I don't use any solvents on handle materials themselves; I'm pretty sure you're right that machining or sanding them right before assembly is the best way to insure that they're clean. I do wipe down the tang with alcohol, and acetone first if it's really greasy.
 
BMK said:
Rough up all surfaces aka increasing surface area of the bond...
Click to expand...

Good point! That's very important, and the Glue Wars study showed huge differences across the board, regarding surface prep, and the strength of bonds on smooth surfaces vs. coarse-sanded or blasted ones.. For the same reason, in jonnymac's current thread he shows drilling shallow divots into the inside of his scales to give even more area for the epoxy to grab onto, a very popular step. It only takes a few seconds and it sure can't hurt :thumbup:

There's nothing stopping a person from making similar divots in the tang itself; the lightening holes we often put in them also serve to allow for "epoxy pins".
 
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