# Wa-Handles: Hidden Tangs, Ferrules, and Wax vs Epoxy



## Kippington

Over the last year I've made many small improvements to my wa-handles (thanks to some quality feedback from you guys!). I find the topic interesting and as there are a few related posts occasionally popping up, I'd like to share some of what I've learned.





The majority of Western makers tend to use epoxy to solidly attach the blade to the handle. This is not a bad thing: Epoxy is extremely tough and able to put up with a lot of abuse. The disadvantage is that the blade can't easily be removed from the handle if it needs to be polished - specifically at the neck of the knife - meaning that keeping, say, a carbon steel knife looking good can be difficult.
With fancier knives such as honyaki, extreme durability in the handle attachment can be a bit overkill as owners tend to reserve the knife for less brutal and forceful tasks such as heavy chopping. They also tend to be the knives that need the most polishing to keep up the good looks. With this, the idea of a removable handle via beeswax installation comes into play.




So what is the difference between the actual handles? Other than the different adhesives, aren't they just the same thing?

It turns out that beeswax is a terrible adhesive, and it can't always be used in the same handle construction.
Unlike epoxy, beeswax doesn't do well at bonding two surfaces together. There is an exception in the case of porous materials such as paper _(i.e. wax sealed envelopes)_ but even in this case the metal stamp used to mark the seal can be pulled away easily to leave an imprint of the stamp without pulling away any of the solidified wax with it. This property would be less than desirable in a handle attachment.



Instead, the reason to use wax in the handle (other than waterproofing the tang) is that it acts in the opposite way of a slippery lubricant - It increases the amount of shear-force needed to slide the touching parts. It can be thought of in the same way as a wet towel or rubber feet on the bottom of a cutting board, stopping it from sliding around the counter-top in a way that doesn't permanently bond the two together.

With this in mind, we can look at how a functional ferrule works to hold the tang.
Think of a hypothetical handle, made in such a way that the tang can just drop into the slot with plenty of wiggle room. Epoxy can be used to flood all of the extra space in the slot, and the tang can be dropped into position in the pool of epoxy and left to cure. The resulting handle could be quite solid with no internal stresses, no problems here. You can push this idea to its extreme by making a handle-shaped mould, flooding the entire thing with epoxy and setting the tang into it to make a 100% epoxy handle... and it would still work.

If we were to try and achieve the same thing with beeswax, even once the wax had been given time to solidify, the handle wouldn't need much force to slide right out again. We need to clamp the tang in place inside the handle to stop it from moving, which is exactly what a functional ferrule helps to achieve.




This brings me to the humble door-stop. You know... the triangle that wedges under your door to stop it from swinging shut. Just like the door-stop, hidden tangs are often tapered into an elongated triangle to wedge themselves into position. With a wax install, the ferrule works like the pressure between a door and the floor the the case of the door-stop. It applies compressive force to the tang, clamping it in place - a critical component of wax installations. It's very important that the handle can maintain this compressive force without stretching or splitting, which is why materials tougher than wood are often chosen for the ferrule. To install the tang with enough force so it doesn't easily move, you will need to strike the bottom of the handle during installation, really clamping the tang in place. When done properly, the more force needed to smack the handle on, the better the grip it has around the wedge-like tang... up until the handle gives out under the strain. In addition, wax in the slot adds even more friction between the parts and can seep into the porous wood when melted, causing the wood to swell and tighten further around the tang.
This application of force during the installation is a noticeable difference in videos on the two types of handles.
_(Wax handle install at 10 minutes into the video)_
----------------------------------------
_(Epoxy handle install at 6 minutes into the video)_

So while it's possible to use epoxy under compression in a handle designed for wax, it's not really possible to use wax in an oversized handle slot designed for epoxy.
Having said all this, the idea of a really good handle install is that the typical user should never be able to tell which method was used... at least up until the the point you want to remove the handle.


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## Bensbites

I have used wax in an oversized slots upon request and know several other people who do it without a problem in both home and pro kitchens. I speak from experience when I say it takes over 100 lbs of force to remove a properly installed room temp wax handle.


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## Kippington

What kind of wax are you using?
I've had nothing but problems using wax to fill gaps in the handle. I'd like to test this out.


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## Bensbites

Kippington said:


> What kind of wax are you using?
> I've had nothing but problems using wax to fill gaps in the handle. I'd like to test this out.




I buy 1 pound beeswax pellets. the last batch I ordered was... 
Beesworks® Beeswax PELLETS,... https://www.amazon.com/dp/B00B3U0FW4?ref=ppx_pop_mob_ap_share

I have one of my first version of this type of install with a very straight tang. I can grab the choil and handle and pull with all my might. At 230 lbs, I go to the gym 4-5 days a week and could be leaner, but I can do a couple pull-ups. I am no wimp. 

If you are having issues, there may also be a technique too. 

1) melt wax

2) fill tang hole

3) let this cool to room temp, 10-30 min. This step is essential to ensure the wax bonds to the wood based on personal experience. 

4) heat a clean tang and plunge it into the wax. Hold the handle /blade straight and true for a few minutes until it cools. 

Take the easy way to test this, drill a 1/2 inch x 3 inch (13 mm x 75 mm ) hole in a plug of wood. Let me know how it works.


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## RDalman

Duuuudes, melt glue!


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## Bensbites

RDalman said:


> Duuuudes, melt glue!


I know that works too.


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## Kippington

Bensbites said:


> Let me know how it works.


Will do. I'll post some tests when I get the time.


RDalman said:


> Duuuudes, melt glue!


What kind of glue? Just hot glue gun stuff?


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## RDalman

Kippington said:


> Will do. I'll post some tests when I get the time.
> 
> What kind of glue? Just hot glue gun stuff?


Yup! Cut some pellets and push into the slot. Heatup end of tang hot, jam it in. Easy cleanup too!


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## Kippington

RDalman said:


> Yup! Cut some pellets and push into the slot. Heatup end of tang hot, jam it in. Easy cleanup too!


Does this mean the handle needs to be heated up for removal? If so, what temp would we be talking about?


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## osakajoe

Second the glue cut pellets. They are pretty good at holding a knife in there. 

Probably need to smash the handle, but don’t see why you’d need to ever remove the handle unless changing it. 

Cleaning the area close to the top of the handle can be done on your endless buffs then good old fashioned nail files and polishers to get in there.


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## RDalman

Kippington said:


> Does this mean the handle needs to be heated up for removal? If so, what temp would we be talking about?



Yea, putting the whole knife in a convection oven at 100c for 5-10 min usually does it.


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## osakajoe

Never even thought about putting a knife in the oven. Nice tip.


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## RonB

As I am just starting my knife making journey, I have a question about using hot glue. Why not drill the tang hole slightly oversize for the glue stick and just drop the stick in the hole?


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## Caleb Cox

That would be way more adhesive than needed, then you'd have an ugly gap next to the tang with visible glue.


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## Gjackson98

Very very nice read Kipp, thank you for sharing! 
I have used epoxy 5min, 15min, 30min, hot glue and beeswax. I agree with your post. I have installed with beeswax before and it struggled big time trying to survive in pro kitchen environment.



Bensbites said:


> If you are having issues, there may also be a technique too.
> 
> 1) melt wax
> 
> 2) fill tang hole
> 
> 3) let this cool to room temp, 10-30 min. This step is essential to ensure the wax bonds to the wood based on personal experience.
> 
> 4) heat a clean tang and plunge it into the wax. Hold the handle /blade straight and true for a few minutes until it cools.
> 
> Take the easy way to test this, drill a 1/2 inch x 3 inch (13 mm x 75 mm ) hole in a plug of wood. Let me know how it works.



I think Ben makes a very good point here as well, I often skip step 3 on his list. I will try again using the list above.


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## Luftmensch

I wanted to follow the non-permanent, food-safe route so I opted for wax



Bensbites said:


> I have used wax in an oversized slots upon request and know several other people who do it without a problem in both home and pro kitchens. I speak from experience when I say it takes over 100 lbs of force to remove a properly installed room temp wax handle.



I agree.... I can't provide as much evidence... my sample size is tiny: me!



Kippington said:


> What kind of wax are you using?



I think this makes a difference. I used pure bees wax (if I recall... purchased relatively cheaply from a local apiarist on ebay) mixed with tung oil. Natural bees wax is surprisingly hard! This is important




Kippington said:


> It turns out that beeswax is a terrible adhesive



Aaaabsolutely. But as you say...



Kippington said:


> Instead, the reason to use wax in the handle (other than waterproofing the tang) is that it acts in the opposite way of a slippery lubricant - It increases the amount of shear-force needed to slide the touching parts.



Perhaps it does increase the coefficient of friction. I suspect not too much? You described it nicely:



Kippington said:


> With a wax install, the ferrule works like the pressure between a door and the floor the the case of the door-stop. It applies compressive force to the tang, clamping it in place - a critical component of wax installations. It's very important that the handle can maintain this compressive force without stretching or splitting, which is why materials tougher than wood are often chosen for the ferrule. To install the tang with enough force so it doesn't easily move, you will need to strike the bottom of the handle during installation, really clamping the tang in place. When done properly, the more force needed to smack the handle on, the better the grip it has around the wedge-like tang... up until the handle gives out under the strain. In addition, wax in the slot adds even more friction between the parts and can seep into the porous wood when melted, causing the wood to swell and tighten further around the tang.



I think this is mostly right... The only part I am not so sure about is the ferrule. It does not apply any force to the tang. Isn't it there to help stop the mouth of the hole from splitting open. A better analogy might be a belt? Since the opening cant split into two as easily, you can push the wood beyond its natural strength. But it is still the wood's resistance to compression that provides the clamping force. Perhaps I am just nit picking - apologies if i am! 

I can see another benefit of wax: it makes the fit more rigid. Depending on how the hole was made (a tight fit) you could get a clamping force down the whole length of the cavity. This is the ideal case - it means you have a large surface area gripping the tang:






When the hole is not tapered with the tang, the only part of the tang that is clamped by the wood is at the mouth of the hole:






Perhaps you can get a higher clamping force with this arrangement? I am not sure... but you aren't providing any resistance to movement right at the end of the tang. Over time you may be able to wiggle the handle free. If you use wax in this scenario, it also plays a roll in keeping the joint rigid. By flooding the chamber with wax, it helps minimise movement by distributing pressure over the entire surface areas of the handle and tang. In turn this should help make the joint less likely to fail.





Kippington said:


> So while it's possible to use epoxy under compression in a handle designed for wax, it's not really possible to use wax in an oversized handle slot designed for epoxy.



I guess it depends.... How big is too big? If you don't have a gaping hole that ruins the aesthetic, you can use wooden shims to help get that tight fit!


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## Carl Kotte

Did my first wax the other day. I messed up, saved it, messed up again and ended up with hot wax all over. I hope I learned something, I’m just not sure what yet [emoji848] We’ll see next time.


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## McMan

I've never had wax work well in the long term.
I think one reason has to do with tapered tangs and that wax mostly provides a mechanical bond (left). As soon as the tang shifts position even slightly (say a fraction of a mm), the mechanical pressure from the wax is diminished. If it shifts forward, that pressure is lost (right). 





Essentially the wax just becomes a mold. The issue is not whether or not the handle can be pulled off after it is installed. The issue is whether or not it can tolerate many repeated small up-down movements without loosening and losing the bond (and then being easily pulled off or, worse, just sliding off).
At least with epoxy or glue there's an adhesive aspect that negates very small movements.


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## Caleb Cox

I'm curious how epoxy with a release agent applied to the tang would work for a tight enough but still removable fit. I have been using Acraglas by Brownells. This is designed for bedding rifle stocks so it's supplied with a release agent.


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## Kippington

Luftmensch said:


> A better analogy might be a belt? Since the opening cant split into two as easily, you can push the wood beyond its natural strength. But it is still the wood's resistance to compression that provides the clamping force. Perhaps I am just nit picking - apologies if i am!


You're right, a belt is actually a really good analogy.

_- "The only part I am not so sure about is the ferrule. It does not apply any force to the tang"
_​I think it's applying force through the wood. Yes, the wood does have a resistance to compression, but it also has some give. I like to think of it like the wooden "soft jaws" you sometimes see on bench vices. The ferrule doesn't directly touch the tang (or most of it anyway), it is acting on the tang through the wood... kinda like a belt not directly touching you but still applying pressure. Without the ferrule, the pressure you could place on the tang using wood by itself would be far less, otherwise it would split (as you mentioned).




And yes, the slot in the handle needs to taper with the tang as you and McMan both illustrated.
I find that wood in compression does a really good job of stopping the tang from shifting a fraction of a mm.
These were hard lessons I learned in the past...



McMan said:


> I've never had wax work well in the long term... Essentially the wax just becomes a mold


Is this in reference to flooded wax alone, or both that as well as wax added to a pressure fit?

I'm glad I wrote this thread! The accumulated group experience far exceeds my own, and there's still plenty for me to learn.


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## inferno

I use epoxy on all my knives. but i still try to make the tang slot as tight as possible. since epoxy itself is not strong. the bond is strong, but in bulk its just plastic. quite ****** plastic.

one thing though. epoxy wont adhere too grease/oil/wax and whatnot. so if one want to reuse a waxed handle you basically have to file/rasp it and maybe even use solvents to get the wax out.

i like to use the epoxys that have the longest setting time i can get. usually 18-24h. regardless of what it says on the package all epoxys take at least 24h to truly fully harden. usually it takes several weeks.
if you paint stuff with epoxy primer you have to wait like a week or so until you can shoot colors on top. even though it technically hardens in like 1h. it outgasses and shrinks and lots of other crap. 

another option that i have not tried is 1 comp polyurethane "waterproof wood glue". this is also used to glue stone walls and such. this is the foaming variety. seems good on paper at least. i have used it for all my wood cabinets and housings, and furniture and such. i think poly absorbs, "wets", better into the wood but i have no scientific data to prove this.

maybe even regular white crapola pva wood glue would work?


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## McMan

Kippington said:


> Is this in reference to flooded wax alone, or both that as well as wax added to a pressure fit?


Both. But issues were more so with flooded wax in a big hole than pressure fit (which was just wax inserted on top of a burn-in, so this isn't really a fit-up with wax).


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## LuvDog

I never thought to use hot glue. Hmmm. I’ll have to try it


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## inferno

its very common on production knives i guess.


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## Gjackson98

Bensbites said:


> I buy 1 pound beeswax pellets. the last batch I ordered was...
> Beesworks[emoji768] Beeswax PELLETS,... https://www.amazon.com/dp/B00B3U0FW4?ref=ppx_pop_mob_ap_share
> 
> I have one of my first version of this type of install with a very straight tang. I can grab the choil and handle and pull with all my might. At 230 lbs, I go to the gym 4-5 days a week and could be leaner, but I can do a couple pull-ups. I am no wimp.
> 
> If you are having issues, there may also be a technique too.
> 
> 1) melt wax
> 
> 2) fill tang hole
> 
> 3) let this cool to room temp, 10-30 min. This step is essential to ensure the wax bonds to the wood based on personal experience.
> 
> 4) heat a clean tang and plunge it into the wax. Hold the handle /blade straight and true for a few minutes until it cools.
> 
> Take the easy way to test this, drill a 1/2 inch x 3 inch (13 mm x 75 mm ) hole in a plug of wood. Let me know how it works.



Ben how do you melt your wax?


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## Kippington

Gjackson98 said:


> Ben how do you melt your wax?


I know of these things designed for wax seals. Might work well.


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## Gjackson98

Kippington said:


> I know of these things designed for wax seals. Might work well.



Cool idea, I just thought of another way... the drug way


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## Kippington

The wax clogged my needle. Wat do?


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## Bensbites

Gjackson98 said:


> Ben how do you melt your wax?



I have the wax in a glass jar I heat in the microwave.

I use a disposable syringe to transfer the hot wax into the tang hole.


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## Gjackson98

Kippington said:


> The wax clogged my needle. Wat do?



Bigger needle will do my friend


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## inferno

Kippington said:


> The wax clogged my needle. Wat do?



those are for babies.
get a 0,8mm needle!


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## Luftmensch

Gjackson98 said:


> Ben how do you melt your wax?



I used a hot water bath.

Put your solid chunks of wax into an old, clean glass bottle - choose an appropriate size, not too big. Place the bottle in a saucepan. If you can raise it off the bottom with a (makeshift) trivet - go ahead. Pour water in the saucepan but no so much that it begins to float. Bring the water to the boil and wait until the wax is melted.

Done!

(Edit: the microwave sounds easier!)


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## Luftmensch

Kippington said:


> The wax clogged my needle.





Bensbites said:


> I use a disposable syringe to transfer the hot wax into the tang hole.



I just taped up the handle to protect it from excess wax and ladled it in!


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## Luftmensch

McMan said:


> Essentially the wax just becomes a mold. The issue is not whether or not the handle can be pulled off after it is installed. The issue is whether or not it can tolerate many repeated small up-down movements without loosening and losing the bond (and then being easily pulled off or, worse, just sliding off).



This is how I see the wax. It prevents those wiggles - you still need the pressure fit with the wood though. It would be a wast of time to use the wax as an adhesive. DONT! It is a sealant that prevents wiggle. Whack the tang and wood together with molten wax and you should have a _reasonably_ durable joint. Like @Kippington says, I think the swelling element can help keep the increase/maintain the clamping force.


Edit:
I guess the nature of the tang has not been discussed.... I think any method would work best with a 'rugged' tang. Polished or smooth-ish tangs have less lumps and bumps to hold the joint in place. Some surface roughness is a good thing!


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## Luftmensch

Kippington said:


> I think it's applying force through the wood. Yes, the wood does have a resistance to compression, but it also has some give. I like to think of it like the wooden "soft jaws" you sometimes see on bench vices. The ferrule doesn't directly touch the tang (or most of it anyway), it is acting on the tang through the wood... kinda like a belt not directly touching you but still applying pressure. Without the ferrule, the pressure you could place on the tang using wood by itself would be far less, otherwise it would split (as you mentioned).



Can't argue with this! The principle is sound! 

I wonder how necessary ferrules are with a good pressure fit? I have no doubt they stop the handle from splitting. If you push the wood just up to its limit, you get the tightest fit without cracking - even without a ferrule. If you push the wood beyond its limit, without a ferrule it will split (no doubt along the grain). With a ferrule, I imagine it will still 'split' but you get to hide your crimes neatly below the ferrule. Perhaps the point at which this occurs is raised by holding everything together?


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## Carl Kotte

Nope, still haven’t learned a thing. Gosh wax is sticky


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## Gjackson98

Carl Kotte said:


> Nope, still haven’t learned a thing. Gosh wax is sticky


The handle looks good Carl, I think if you heat up a metal stick (metal chopsticks or tip of a fork) and run it back and forth on exposed wax, it will melt it down, just clean it up before it cool down you should be good.


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## Gjackson98

Carl Kotte said:


> Nope, still haven’t learned a thing. Gosh wax is sticky


and yes wax was sticky and when messy. I tried to fill the tang full with wax first then installed the handle. it worked great to stabilized the tang and confirmed no gaps (I hope) but it was mess everywhere.
Maybe next time I will go half way.


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## JoBone

I put masking tape at the front of the handle and board butter on the rest when doing an install to protect from errant epoxy. Should help with any install. I also put a small bit of tape on the top of the handle to help orient. If there is a KU finish on the blade, I just put a small amount of tape on the edge of the blade.


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## Carl Kotte

Gjackson98 said:


> The handle looks good Carl, I think if you heat up a metal stick (metal chopsticks or tip of a fork) and run it back and forth on exposed wax, it will melt it down, just clean it up before it cool down you should be good.



Thank you very much! And Thanks for the advice! Will do! [emoji1303]


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## Luftmensch

Gjackson98 said:


> The handle looks good Carl, I think if you heat up a metal stick (metal chopsticks or tip of a fork) and run it back and forth on exposed wax, it will melt it down, just clean it up before it cool down you should be good.



Careful application of a heat gun (if you have one) will likely work.... heck... _maybe_ your hair drier will!


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## Jesse Killion

As luftmensch said, double boil your beeswax. I also add mineral oil once the wax is melted to make it able to spread once cooled so you can make a large batch at once and not have to continually remelt it. I also bed the tangs on all of my knives which entails covering the tang, ferule/bolster face and any other mating surfaces with wax and or teflon tape, filling the tang hole in the handle with epoxy and mating the two together until the epoxy cures. Once cured, the handle will come off and you will be left with a perfect mold of your tang to which you can then either wax or epoxy "adhere" the blade to the handle. Not sure if this will help anyone, but one of the tricks I've learned along the way.


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## Kippington

Has anyone heard of this stuff before? I'm just learning about it now...



> *Cutler's resin* is a synthetic resin made of pine pitch, beeswax, and sawdust or carnauba wax used for centuries (to today) to attach knife handles. It is used as both an adhesive and for waterproofing. The word cutler means "one who makes knives", hence the word "cutlery".



It seems like traditionally it was hard pine resin or rosin that was used as the adhesive, with beeswax, oil or tallow melted into the mix to modulate its properties (increase toughness) and some kind of fine aggregate (sawdust, charcoal powder or metal filings) to increase hardened stability.


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## Tim Rowland

Never heard of it but I'm intrigued. 
Now Im gonna spend countless hours reading about it and asking a few of the older guys in my guild.


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## Kippington

Tim Rowland said:


> Never heard of it but I'm intrigued.
> Now Im gonna spend countless hours reading about it and asking a few of the older guys in my guild.


Yeah... its making a lot of sense the more I look into it.
I mean, beeswax alone is generally considered to be a lubricant - not the ideal thing for holding handles on knives - but rosin on the other hand...


> Rosin is extensively used for its friction-increasing capacity in several fields:
> 
> Players of bowed string instruments rub cakes or blocks of rosin on their bow hair so it can grip the strings and make them speak, or vibrate clearly.[3] Extra substances such as beeswax, gold, silver, tin, or meteoric iron[4] are sometimes added to the rosin to modify its stiction/friction properties and the tone it produces.[5] Powdered rosin can be applied to new hair, for example with a felt pad or cloth, to reduce the time taken in getting sufficient rosin onto the hair. Rosin is often reapplied immediately before playing the instrument. Lighter rosin is generally preferred for violins and violas, and in high-humidity climates, while darker rosins are preferred for cellos, and for players in cool, dry areas.[6] There are also specific, distinguishing types for basses—for more see Bow (music).
> Violin rosin can be applied to the bridges in other musical instruments, such as the banjo and banjolele, in order to prevent the bridge from moving during vigorous playing.
> Ballet, flamenco, and Irish dancers are known to rub the tips and heels of their shoes in powdered rosin to reduce slippage on clean wooden dance floors or competition/performance stages. It was at one time used in the same way in fencing and is still used as such by boxers.
> Gymnasts and team handball players use it to improve grip. Rock climbers have used it in some locations, but it fouls the rock, so usage is now highly discouraged.
> Olympic weightlifters rub the soles of their weightlifting boots in rosin to improve traction on the platform.
> It is applied onto the starting line of drag racing courses used to improve traction.
> Bull riders rub rosin on their rope and glove for additional grip.
> Baseball pitchers and ten-pin bowlers may use a small cloth bag of powdered rosin for better ball control.
> Rosin can be applied to the hands in aerial acrobatics such as aerial silks and pole dancing to increase grip.


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## McMan

Kippington said:


> Has anyone heard of this stuff before? I'm just learning about it now...
> 
> 
> 
> It seems like traditionally it was hard pine resin or rosin that was used as the adhesive, with beeswax, oil or tallow melted into the mix to modulate its properties (increase toughness) and some kind of fine aggregate (sawdust, charcoal powder or metal filings) to increase hardened stability.



IIRC this was also called "rozzle" (sp?). I've seen it on very old (c. 1890) nogent sabatiers. I know because I cracked a few of the old handles off and it was in the cavity. Even after all that time it was still hard, still working, and still a PITA to scrape off the tang. Resin + hide glue + aggregate (saw dust) was my guess at the time. Kinda a pre-epoxy system?


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## McMan

Gazillion threads/recipes (actually, more like 4 or 5) over at bladesmithforum. Here's one:





Cutler's resin- a "secret" of Medieval swords?


For hundreds if not thousands of years, various resin compounds have been used in securing or waterproofing knife and sword grips, guards, etc, usually with various mixtures of tree resins and beeswax. Just recently finishing up a longsword and sealing the guard and filling the grip with my own m...



www.bladesmithsforum.com


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## Kippington

Yeah I saw some of those threads in my research. Honestly I'm just surprised I haven't seen anything about it on KKF before.



McMan said:


> IIRC this was also called "rozzle" (sp?). I've seen it on very old (c. 1890) nogent sabatiers. I know because I cracked a few of the old handles off and it was in the cavity. Even after all that time it was still hard, still working, and still a PITA to scrape off the tang. Resin + hide glue + aggregate (saw dust) was my guess at the time. Kinda a pre-epoxy system?


Sounds about right to me. Rozzle is a sick name for it!


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## JoBone

Looks like cool stuff, I want to give it a go


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## M1k3

Kippington brand Rozzle on the horizon?


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## Luftmensch

Kippington said:


> Has anyone heard of this stuff before? I'm just learning about it now...



Yes and no! I've never seen someone extract pine sap on a campfire before. Thanks for that!!

I haven't heard of cutler's resin specifically but resin and pitch turn up a lot in old-world carpentry. If you've played a stringed instrument or hung around musicians, rosin will be familiar. Rubbing your fingers on it is a fun experience. The friction it provides is quite something! Resin is also pretty durable stuff. Pitch probably would have been part of the critical supply chain in the days of wooden sailing ship super powers (Spain, France, England). 

The problem with rosin is that it is very brittle. Again, if you've handled it in the context of stringed instruments, dropping rosin can cause it to crack and break into shards. You can imagine how mixing rosin and wax combines usefully combines the material properties. Like you noted, you get a material with a higher coefficient of friction than wax and higher toughness than rosin  

While beeswax is in no way a glue it does set surprisingly hard. It probably isn't the right material for a machete, hammer or axe handles... but not a bad choice for a kitchen knife with a friction fit. It would be terrible at keeping a really smooth, polished tang in place. But a nice craggy tang with slag and hammer marks? Sure.


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## Kippington

Luftmensch said:


> ...resin and pitch turn up a lot in old-world carpentry...


Yeah the stuff is everywhere and is fascinating. Used for water-proofing, varnishes, adhesives, sealants, food glazing agents, casting, and can occur naturally or be made from plants or synthetic materials (mostly petroleum).





I stumbled across '_cutler's resin'_ while I was looking into how asphalt/bitumen behaves (the stuff on the roads) and the pitch drop experiment - '_the world's longest continuously running laboratory experiment'_. Basically it's a fluid that's so viscous, you can shatter it with a hammer... but it will still flow through a funnel if you give it a few decades. It flows better if heated up, so it has a lot of similarities to the hot glue gun stuff mentioned earlier in this thread.


> A *pitch drop experiment* is a long-term experiment which measures the flow of a piece of pitch over many years. 'Pitch' is the name for any of a number of highly viscous liquids which appear solid, most commonly bitumen. At room temperature, tar pitch flows at a very low rate, taking several years to form a single drop.
> The best known version[1] of the experiment was started in 1927 by Professor Thomas Parnell of the University of Queensland in Brisbane, Australia, to demonstrate to students that some substances which appear solid are actually *highly viscous fluids*. Parnell poured a heated sample of pitch into a sealed funnel and allowed it to settle for three years. In 1930, the seal at the neck of the funnel was cut, allowing the pitch to start flowing. A glass dome covers the funnel and it is placed on display outside a lecture theatre.[2] Large droplets form and fall over a period of about a decade. The eighth drop fell on 28 November 2000, allowing experimenters to calculate the pitch as having a viscosity of approximately 230 billion (2.3×1011) times that of water.


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## Luftmensch

Hehe! How'd you land up researching bitumen?!!


Do you like podcasts?

If so, RadioLab (if you don't already know it) has some great segments*. This segment is on the pitch drop experiment:

Never Quite Now | Radiolab | WNYC Studios

Quite fun to listen to!

* Although I feel their best work was early to mid 2010's


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## Bear

I use a concoction of bees wax, parafin wax, bow rosin, and castor oil to make various types of wax's for fly tying, dubbing wax and thread wax. Just be careful, you don't want to get any of this stuff on you, and watch any open flames.


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## toddnmd

I recently installed some handles with melt glue, and was pleased with the results. The process allowed some fine tuning on a second try using a low temp oven. Did a final seal using beeswax. 
I prefer this over epoxy.


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## GBT-Splint

RDalman said:


> Yea, putting the whole knife in a convection oven at 100c for 5-10 min usually does it.


Isn't heat supposed to be bad for the knife ?

Just saying because I just hot glued a handle on a munetoshi gyuto for the first time but I couldn't insert the tang all the way in the handle as I would have liked .. (my mistake is probably that I didn't heat the tang. or is it ?) The hot glue got cold waay faster than what I expected, what would you suggest I do ? 

If heat doesn't do anything to the knife then I guess I will stick it in oven softening the glue and pushing the knife further in the handle.


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## RDalman

GBT-Splint said:


> Isn't heat supposed to be bad for the knife ?
> 
> Just saying because I just hot glued a handle on a munetoshi gyuto for the first time but I couldn't insert the tang all the way in the handle as I would have liked .. (my mistake is probably that I didn't heat the tang. or is it ?) The hot glue got cold waay faster than what I expected, what would you suggest I do ?
> 
> If heat doesn't do anything to the knife then I guess I will stick it in oven softening the glue and pushing the knife further in the handle.


Yes you use cut up cold pellets to fill in the handle slot, then torch the tang hot and insert. If you dont get to bottom pull out immediately and torch more. Up to 150c is safe, 100 is mildest for the wood, once I had to go ~120 that worked too, depends some on the glue. Some margins are good as convection ovens thermostats can tend to be funky/inaccurate. 150c is I'd say minimum general tempering temp. Common range to use is more like 170 and up.


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## Barmoley

Some hot glues melt at ~80C, but most around ~120C or so. 100-120C is fine for knives steel and gets most hot glues at least soft, so you shouldn't have a problem at these low temps.


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## GBT-Splint

Ok thanks you guys for the info, I kind of knew that 100 degres or so wouldn't engendre no alteration of the molecular structure of the steel but still I needed someone to tell me it's fine to put my beloved in the oven 

knife in the oven at 100 celcius right now


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## SeattleB

I recently installed my first handle and used hot glue. I put a pan of water on the stove (2 liter saucepan) and put the tang end of the knife in the water for a few minutes. I knew that 100 C isn't enough to melt the glue readily. The next step was to pull it out and use a torch on the very end of the tang for about 10 seconds, and then insert the tang into the handle half-filled with glue chips. The higher heat of the torched tang melted the glue quickly (it doesn't take much) and the heat on the rest of the blade prevented the tang from cooling too quickly. I had over a minute of working time before it set up but that probably depends upon the brand of glue. 

The only hard part is guessing how many glue chips to put in the handle.


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## Towerguy

Kippington said:


> Over the last year I've made many small improvements to my wa-handles (thanks to some quality feedback from you guys!). I find the topic interesting and as there are a few related posts occasionally popping up, I'd like to share some of what I've learned.
> 
> 
> 
> 
> 
> The majority of Western makers tend to use epoxy to solidly attach the blade to the handle. This is not a bad thing: Epoxy is extremely tough and able to put up with a lot of abuse. The disadvantage is that the blade can't easily be removed from the handle if it needs to be polished - specifically at the neck of the knife - meaning that keeping, say, a carbon steel knife looking good can be difficult.
> With fancier knives such as honyaki, extreme durability in the handle attachment can be a bit overkill as owners tend to reserve the knife for less brutal and forceful tasks such as heavy chopping. They also tend to be the knives that need the most polishing to keep up the good looks. With this, the idea of a removable handle via beeswax installation comes into play.
> 
> 
> 
> 
> So what is the difference between the actual handles? Other than the different adhesives, aren't they just the same thing?
> 
> It turns out that beeswax is a terrible adhesive, and it can't always be used in the same handle construction.
> Unlike epoxy, beeswax doesn't do well at bonding two surfaces together. There is an exception in the case of porous materials such as paper _(i.e. wax sealed envelopes)_ but even in this case the metal stamp used to mark the seal can be pulled away easily to leave an imprint of the stamp without pulling away any of the solidified wax with it. This property would be less than desirable in a handle attachment.
> 
> 
> 
> Instead, the reason to use wax in the handle (other than waterproofing the tang) is that it acts in the opposite way of a slippery lubricant - It increases the amount of shear-force needed to slide the touching parts. It can be thought of in the same way as a wet towel or rubber feet on the bottom of a cutting board, stopping it from sliding around the counter-top in a way that doesn't permanently bond the two together.
> 
> With this in mind, we can look at how a functional ferrule works to hold the tang.
> Think of a hypothetical handle, made in such a way that the tang can just drop into the slot with plenty of wiggle room. Epoxy can be used to flood all of the extra space in the slot, and the tang can be dropped into position in the pool of epoxy and left to cure. The resulting handle could be quite solid with no internal stresses, no problems here. You can push this idea to its extreme by making a handle-shaped mould, flooding the entire thing with epoxy and setting the tang into it to make a 100% epoxy handle... and it would still work.
> 
> If we were to try and achieve the same thing with beeswax, even once the wax had been given time to solidify, the handle wouldn't need much force to slide right out again. We need to clamp the tang in place inside the handle to stop it from moving, which is exactly what a functional ferrule helps to achieve.
> 
> 
> 
> 
> This brings me to the humble door-stop. You know... the triangle that wedges under your door to stop it from swinging shut. Just like the door-stop, hidden tangs are often tapered into an elongated triangle to wedge themselves into position. With a wax install, the ferrule works like the pressure between a door and the floor the the case of the door-stop. It applies compressive force to the tang, clamping it in place - a critical component of wax installations. It's very important that the handle can maintain this compressive force without stretching or splitting, which is why materials tougher than wood are often chosen for the ferrule. To install the tang with enough force so it doesn't easily move, you will need to strike the bottom of the handle during installation, really clamping the tang in place. When done properly, the more force needed to smack the handle on, the better the grip it has around the wedge-like tang... up until the handle gives out under the strain. In addition, wax in the slot adds even more friction between the parts and can seep into the porous wood when melted, causing the wood to swell and tighten further around the tang.
> This application of force during the installation is a noticeable difference in videos on the two types of handles.
> _(Wax handle install at 10 minutes into the video)_
> ----------------------------------------
> _(Epoxy handle install at 6 minutes into the video)_
> 
> So while it's possible to use epoxy under compression in a handle designed for wax, it's not really possible to use wax in an oversized handle slot designed for epoxy.
> Having said all this, the idea of a really good handle install is that the typical user should never be able to tell which method was used... at least up until the the point you want to remove the handle.



Anyone use hot melt glue. That is a good adhesive and can be removed with the application of heat.


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## Kippington

Towerguy said:


> Anyone use hot melt glue. That is a good adhesive and can be removed with the application of heat.


I take it you haven't read the thread yet...


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## jsph

with this semi-necro- thread semi-recently semi-revivified, one wonders to which technique/material mr kippington may have eventually converged over the last >year of such careful examination.... (equally answerable, i suppose, by his enviable patrons of the last few months if not the busy man himself.)


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## Kippington

*- Roses are red,*
_*- Violets are blue.
- Have you guys tried,*_
*- Using hot glue?*



jsph said:


> with this semi-necro- thread semi-recently semi-revivified, one wonders to which technique/material mr kippington may have eventually converged over the last >year of such careful examination.... (equally answerable, i suppose, by his enviable patrons of the last few months if not the busy man himself.)


I've spent the last few months improving my normal beeswax method by small increments.


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## Luftmensch

Kippington said:


> I've spent the last few months improving my normal beeswax method by small increments.



Any tips you think would add value?

I have only used 'standard' pre-made handles. It might be different with more carefully made tang holes. I found making little shims out of a paddle pop to wedge the tang can create a pretty solid friction fit. The wax just fills the void and prevents wiggle. I recently removed a two year old handle using this method - I put the handle in a boiling water bath to soften the wax. Even after the wax softened it was still stubborn and need whacks to come off!

Worked on gyutos... probably not a butchers cleaver 

When is your organic, hand plucked pine rosin going to be used?


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## ian

I hope to eventually realize why a friction fit is even necessary with beeswax. My two wax installs with grand canyon sized tang slots have been going strong for at least 6 months now, no loss in stability. Probably it’s just the small sample size and the gentle use.


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## Carl Kotte

ian said:


> I hope to eventually realize why a friction fit is even necessary with beeswax. My two wax installs with grand canyon sized tang slots have been going strong for at least 6 months now, no loss in stability. Probably it’s just the small sample size and the gentle use.


Learn to love the hole!


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## ian




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## cotedupy

*Tang*entially related to all this...

I use epoxy to install, and yeah it can be tricky to get something out. But I've also removed epoxied handles quite a lot, and it can be done easily enough without damaging the handle, once you stop thinking about it like regular glue. (I don't know the science behind this, it's pure empiricism, but it works).

If you heat epoxy and then try the piece-of-wood-and-a-hammer method you're not going to break the bond. It'd just get very marginally softer, and re-set. Shock force gets you nowhere, but shock temperature does. And your tang, with its thermal conduction, is quite a useful bit of kit here.

If you wang your knife in a 90-100 degree oven for ten mins, as you might for removing a glue-d handle, then run the blade under cold water / dunk it into iced water, you'll take all of the heat out of the tang very quickly and start breaking the bond with the still warm epoxy. And then, acting quickly, you can hammer or pull the handle off.

Works for me anyway!


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## ian

Huh, that’s super interesting. Gotta try


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## inferno

i like epoxy. that way you don't have to remove the handle later on. and you can't. easy as that.


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## Luftmensch

ian said:


> grand canyon sized tang slots





ian said:


> small sample size



I'm getting confused by all the euphemisms. Does this have something to do with your special handle? Does it need to see a urologist?




cotedupy said:


> If you wang



So let me get this straight?

Wang your tang next to the meringue? Chill, with no hang. Then the handle will come off with one bang?


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## Luftmensch

cotedupy said:


> I don't know the science behind this



Different rates of thermal expansion between the materials? Small movement but quite a strong force? Enough to break an adhesive bond?

I tried the opposite! I was too scared to go hot so I went cold. I put a knife with an epoxied handle in the freezer. I left it in there overnight, took it out and poured boiling water over the handle. I dont know if it worked... It _did_ come off but it was still a pain (and I had failed previously).

Maybe it is a bit like that stuck pickle jar you give to a friend - who subsequently fails to open it but get to make the refrain "yeah but I loosened it".


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## NO ChoP!

Speaking as a 30+ year chef and a handle maker, I am very hard on knives. From cutting cases of heavy squash, to breaking down whole fish, to general meat fab, etc...

I will tell you, I have flexed well built handles apart. I will only ever use epoxy. 

Send me a knife without dowel construction or bees wax install and I will put it through a week of real life hard use. Just don't be too attached to the handle.


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## cotedupy

Luftmensch said:


> Different rates of thermal expansion between the materials? Small movement but quite a strong force? Enough to break an adhesive bond?
> 
> I tried the opposite! I was too scared to go hot so I went cold. I put a knife with an epoxied handle in the freezer. I left it in there overnight, took it out and poured boiling water over the handle. I don't know if it worked... It _did_ come off but it was still a pain (and I had failed previously).
> 
> Maybe it is a bit like that stuck pickle jar you give to a friend - who subsequently fails to open it but get to make the refrain "yeah but I loosened it".



Aye something to do with that I imagine. More that I didn't know whether there was something about the composition of epoxy that meant force alone wouldn't work, but rapid temp changes did. Or maybe as you say - it's just stronger stuff and needs a variety of methods to loosen it.

I hand't thought of doing it the other way round, interesting. We're clearly onto something!


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