Metal spacers on WA handles

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icanhaschzbrgr

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Hello KKF professionals :)

Another newbie question here.
While practicing in making WA handles I tried to use metal spacers but failed so far.

At first I've tried the simplest method: glueing together metal and wood with epoxy. Worked pretty badly: I could tear them apart by hands pretty easily (when I epoxied only wood pieces I couldn't tear them apart). Second attempt involved kydex in between metal and wood, but that's not what I really want.

What method works for you?
One idea is to drill bigger hole in wood and metal and insert tube inside to enforce construction, but I'm not sure it would help. And it wont work if I wanted to use metal on the end cap of handle.

Also I find it hard to make metal spacer flat after cutting it from a big plate with hacksaw. Any ideas how to do it properly?


All the best,
Anton
 
Hi Anton, Epoxy should work just fine. Did you sand (roughen up) the surface of the metal spacers befor glueing? Once you have the handle mounted the tang will make the construction much more sturdy.
 
I did sanded metal part with ~100 grit sandpaper but it doesn't helped. Might try other epoxy…
I do understand that once inserted tang would make construction more sturdy, but I'm afraid I would break it while shaping handle with disk sander. Anyway, gonna make 2 more tests with different metal pieces and different wood.

Thanks for the input
 
What about thin fiber spacers. You can get them in black, and they're almost invisible. The fiber really soaks up the epoxy.
 
Try a different epoxy and take it slow while sanding. Don't let the metal get too hot, or it melts the epoxy and you lose your bond. Patience.
 
Try a different epoxy and take it slow while sanding. Don't let the metal get too hot, or it melts the epoxy and you lose your bond. Patience.

Thanks Chris!
I've ordered some epoxy from US but it might take another year or two to ship here (if I'm lucky). Btw my experience with epoxy is limited to the one I'm using right now. And on the tubes it says that epoxy would be most strong if put into oven for 5-7 hours under 60-70˚C (140-160 F). Is it the same for all epoxies?
 
As already mentioned, roughing the gluing surface and cleaning it very well with acetone or something like that is essential. but any bonds between metal and wood are much weaker than between wood and wood. I tried about a dozen epoxies and the differences are marginal. These handles drove me nuts until I thought about using a dowel for them - I am drilling into the pieces, including the metal spacer, to 1/2" diameter and then insert a 1/2" soft wood dowel that connects the pieces, with all the spacers just sliding over the dowel. That way the handle gets additional strength from the inside and when you drill it out for the tang, there will still some wood be left inside that strengthens it. More work but handles are much less liely to break at the gluing points.

Stefan
 
…one thing I truly appreciate on KKF is how people are open in sharing their experience. For some of you those knowledge could costs hours or days of hard work, and now I'm getting them for free. Fantastic :)

Thanks Stefan!
 
As already mentioned, roughing the gluing surface and cleaning it very well with acetone or something like that is essential. but any bonds between metal and wood are much weaker than between wood and wood. I tried about a dozen epoxies and the differences are marginal. These handles drove me nuts until I thought about using a dowel for them - I am drilling into the pieces, including the metal spacer, to 1/2" diameter and then insert a 1/2" soft wood dowel that connects the pieces, with all the spacers just sliding over the dowel. That way the handle gets additional strength from the inside and when you drill it out for the tang, there will still some wood be left inside that strengthens it. More work but handles are much less liely to break at the gluing points.

Stefan

+1 I do the same thing. The dowel makes a huge difference. It also has the added benefit of letting you have more control over the handle weight when using heavy/dense exotic materials.

Another trick that I think helps (but may be overkill) is to pre-glue the end grain of the wood pieces you are joining against the metal. Essentially, take a little bit of any good wood glue and coat your end grain well. Let that glue dry....lightly sand to make sure you're level.....then proceed with the rest of the glue up and epoxy process.
This may or may not help the joint at initial assembly. (In theory, it keeps the end grain from sucking up glue like straws so the glue joint between wood and metal will be stronger...but not sure with epoxy). What it does do for sure is help prevent movement (expansion/contraction) issues on the finished handle.

The idea is stolen from old cabinet maker tricks for joining wood pieces with opposite grain...end grain/cross grain etc. The pre-glue helps stabilize the area so that when the woods move in different directions as they expand or contract...the movements are reduced and the joint becomes less likely to pull apart. Here, since the metal and wood in the handle joint are going to respond to temperature and humidity very differently, which could cause ridges in the future, the pre-glue is a safety measure to help.
 
Thanks Chris!
I've ordered some epoxy from US but it might take another year or two to ship here (if I'm lucky). Btw my experience with epoxy is limited to the one I'm using right now. And on the tubes it says that epoxy would be most strong if put into oven for 5-7 hours under 60-70˚C (140-160 F). Is it the same for all epoxies?

impact of temp and time on epoxies vary quite a bit. There are epoxies meant for fast and slow curing...epoxies meant for industrial high temp curing...and slow open air stuff. ...all depending on the chemical mix. In general, slower curing epoxies are stronger when it comes to air cured stuff. Here, for knife projects, seems the general view is the difference between most good epoxies for our uses is small. Think I recall a table showing time/temp impact to strength on System 3's website... might be worth a check if curious.

Personally, I like G-Flex for knife projects. It's strong stuff....but also has a slight amount of flexibility in the final glue joint (nothing we can feel in use)...that helps with any expansion/contraction. But any West, System 3 or other good epoxy should more than get the job done.
 
How about glue up everything onto the tang and then shape the handle while it's on the knife?
 
Can you do that with a wa?

I've never done it....but.....I'd think it possible with using a disc sander vs belt grinder....at least that's what I hope is the case. :)


FWIW - I do this for hidden tang westerns all the time using the belt grinder.
 
I've never done it....but.....I'd think it possible with using a disc sander vs belt grinder....at least that's what I hope is the case. :)


FWIW - I do this for hidden tang westerns all the time using the belt grinder.

I've never done a wa that way either, but I'd guess you could too. I'd think it might be harder to control the shaping process, though....suppose it would depend on shape (D or Octo) and tools.
Ultimately, no wrong methods for this if the end result works.

Personally, I like the extra insurance of doing the handle separately. If I screw it up or am unhappy with something.... there's no worries about making a mess of the knife too. Also, I have a lot more leeway shaping -- more tools to use, as needed....easier to maneuver the blank around sanders.

Metal spacers on Wa's is definitely tricky. I try to pre-cut my pieces close to the final shape before assembling (to minimizing grinding/sanding needed) and I always use a hidden dowel in the middle. With the dowel, the wood above and below the spacer are both attached to the dowel so even if the metal to wood glue joints have a problem, the pieces above and below are fixed in their positions and able to function almost like a clamp that holds the metal.

I've used 5/8 dowels and 1/2 depending on the thickness of the final handle and size of the tang.
 
because im so new at trying my hand at making handles i think i would be nervous that the middle of the handle where you insert the tang might not be centered anymore after sanding and shaping...
 
The problem is not the glue/epoxy. Metal expands at a much greater rate than other natural or synthetic materials when it heats up. Thermal expansion of the metal spacer causes it to shear from whatever it is glued to.

Hoss
 
I guess if I would try using metal for an end cap it would make sense to use a shirt pin instead of dowel, right?
 
What is a shirt pin if I may ask? Also I think what DT was trying to emphasize is that you need to keep the metal cool when sanding or else it will break off of anything that it is glued to. I would just sand with fresh abrasives in short bursts and cool it down with water or something in between sanding runs.

But as usual I know very little of what I am talking about.
 
I think it was a typo, I think he means a short pin.

And yes, even a small amount of heat will cause the metal to expand and break loose from the material that it is glued to.

Hoss
 
Yep, it was just a typo, thanks Davin!

Right now I have a glued up prototype handle blank with metal spacer. With a dowel inside it looks pretty strong now… at least I'm unable to split it with bare hands. The big mistake I've made with this prototype — made it too big, so that I need to sand few millimeters from each side. Oh well… at least I'll have a lot of practice sanding metal and trying not overheat it.

Thanks for you replies guys.
 
Devin's definitely right ... expansion is the biggest problem when sanding combined wood and metal. This said, heat also softens epoxy very quickly. When I'm working handles with metal spacers, I've developed a couple of tricks that seem to make it go smoothly. Some have already been noted:
- make sure to roughen the surface of the metal. 60 grit is good.
- work cold ... use a sharp belt. Sand the metal down to meet the wood with a rough belt (60 grit). If you start feeling any heat, put it down and go to another project for a few minutes to let it cool down.
- don't dunk the handle in water to cool it down. This will make your expansion/contraction problem bigger.
- this is the big one: after gluing the handle together let it cure for 24 hours. After that, I put the handles in a cabinet with a 100 watt light bulb in it and leave it there for 12 hours. Then I proceed to grind. Epoxy will soften very quickly when it is heated ... the FIRST time. By doing this additional heated cure, the epoxy will not soften as easily afterward. The difference is HUGE.

-daniel
 
How about glue up everything onto the tang and then shape the handle while it's on the knife?

I tried this a few times after I was frustrated when handles loosened up while working on them. Then one time I accidentally dinged the blade while working on the handle.... abandoned this approach after that. In some ways, it is so much easier, since the entire handle is so much more stable, but the danger of damaging when doing some of the finish work is too high for me ... I suppose we do it all the time on Western handles and don't have any trouble, but for some reason Wa handles seem to be harder to deal with this way (for me).

-daniel
 
…one thing I truly appreciate on KKF is how people are open in sharing their experience. For some of you those knowledge could costs hours or days of hard work, and now I'm getting them for free. Fantastic :)

I agree! This is the best knife community, period
 

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