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

[inferno]

The wax clogged my needle. Wat do?

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

 

[Luftmensch]

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!)

 

[Luftmensch]

The wax clogged my needle.

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!

 

[Luftmensch]

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!

 

[Luftmensch]

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?

 

[Carl Kotte]

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

 

[Gjackson98]

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.

 

[Gjackson98]

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.

 

[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.

 

[Carl Kotte]

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]

 

[Luftmensch]

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!

 

[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.

 

[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.

 

[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.

 

[Kippington]

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.

 

[McMan]

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?

 

[McMan]

Gazillion threads/recipes (actually, more like 4 or 5) over at bladesmithforum. Here's one:
https://www.bladesmithsforum.com/index.php?/topic/22616-cutlers-resin-a-secret-of-medieval-swords/

 

[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.

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!

 

[JoBone]

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

 

[M1k3]

Kippington brand Rozzle on the horizon?

 

[Luftmensch]

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.

 

[Kippington]

...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.

 

[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

 

[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.

 

[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.

 

[GBT-Splint]

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.

 

[RDalman]

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.

 

[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.

 

[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

 

[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.