Cutlers resin

[Geoff Keyes]

I found an old thread (Tai Goo is part of it, that's how old) about cutlers resin recipe's, but I'm wondering if there is any new info around.  I have a piece of some sort of antelope horn (Springbok I think) that is mostly hollow.  I'd like to fill it, but epoxy will be heavy and produce a fair bit of heat as it cures.  What else could I use?  I've considered bedding pellets, which are compressed sawdust.  Break those down and combine with wax?  For the area around the tang I would use epoxy, but for the rest, something a bit lighter to fill up the space is what I'm after.

 

Thanks

 

g

[Jeroen Zuiderwijk]

The stuff tulwars are fixed in their hilts would be perfect for that. Unfortunately I still don't know the exact recipe. At least it's resin based, and has a temperature range where it can be used based on the sort of temperatures experienced in India. So it should still be quite solid in the hot sun. 

 

Note: I just found that the glue on tulwars is called laakh. 

[Geoff Keyes]

Laakh appears to be Lac, as in lacquer, the real bug based stuff.  That makes sense, but more work than I want to go through for this piece.  I have some old American pieces that are cemented into the handles (sliver and ivory) and when you heat it, it smells like pine and bees wax (and sometimes animal dung).  Still holding strong after 100+ years

 

 

Geoff 

[Alan Longmire]

I'm guessing that was this thread?

 

Long ago (2003?) Tai was selling pinon pitch he was collecting himself.  Talk about smelling good!  He's still around over on the Outpost at knifenetworkforums. 

 

Here's the outside thread linked in that thread as well:

 

https://leatherworker.net/forum/topic/23929-all-about-cutlers-resin/

 

I haven't heard anything new, except maybe that chasing pitch can be used in place of raw pine pitch...I don't have either on hand, so I can't try it out.  Cutlers' resin is one of those things on my "one of these days" list.  Me being a 19th century kind of guy I'll probably use brick dust instead of moose poo, but that resonated with Tai's neotribal thing he had going on at the time.

 

[Carlos Lara]

I have some chasing pitch, I could send you a sample if you want to try some. Hard as a rock when dry, sticky as tar when heated. Takes a while to cure, but it would actually have a pretty good hold. I just took some off a kozuka handle that was 100 years old that still held pretty well (but that was Japanese stuff, was used to hold a menuki on the handle).

 

I also recently got hold of some birch tar. Apparently that has also been used as a sort of cutler's resin over time. Not had time to try it yet though.

 

They say hide glue also adheres well to horn. If you get a good goop in the inside, it will never come off. Apparently they had glue like that in the Bronze age. It can get wet, but if you let it soak, it will come apart. The Japanese use it for various sword parts (gluing on the kurikata and kojiri, sometimes also gluing on the fuchi and kashira). The Japanese call it nikawa.

 

The Japanese have another resin they use to hold ito onto the tsuka called matsuyani that is basically just pine resin I think. Have some of that too, probably pretty similar to the chasing pitch, I would think. This is also used to glue the blade of a kozuka in.

Edited November 2 by Carlos Lara

[Geoff Keyes]

One of my favorite stories from Lewis and Clark is the tale of the iron boat.  Lewis (if memory serves) commissioned an iron boat frame for the expedition.  The plan was to cover it in hides and dope the seams with pine pitch.  They made a trial run in the East and it worked fine.

The thing to remember is that they knew less about the environment of the West than modern man knows about the back side of the moon.

 

When they got up toward the headwaters of the Missouri river, they decided it was time to deploy the iron boat.  They camped for a couple of weeks, assembling the boat, hunting moose, tanning the hides, and collecting pine pitch.  The last thing turned out to be a problem.  There were lots of Fir trees, but no Pines to speak of, and none of them provided pine tar.  They decided to try and make do with Fir resin.  They got the boat all built and the hides on and doped up with Fir pitch.  They launched the boat and it went about 100 yards and all of the seams failed and the iron boat sank like a rock.  The frame is still in the river.

 

No pine trees, who knew?

 

Geoff

[Joshua States]

My favorite for filling interiors and bedding tangs is JB Weld Quick wood.

[Jeroen Zuiderwijk]

13 hours ago, Carlos Lara said:

I have some chasing pitch, I could send you a sample if you want to try some. Hard as a rock when dry, sticky as tar when heated. Takes a while to cure, but it would actually have a pretty good hold. I just took some off a kozuka handle that was 100 years old that still held pretty well (but that was Japanese stuff, was used to hold a menuki on the handle).

 

I also recently got hold of some birch tar. Apparently that has also been used as a sort of cutler's resin over time. Not had time to try it yet though.

 

They say hide glue also adheres well to horn. If you get a good goop in the inside, it will never come off. Apparently they had glue like that in the Bronze age. It can get wet, but if you let it soak, it will come apart. The Japanese use it for various sword parts (gluing on the kurikata and kojiri, sometimes also gluing on the fuchi and kashira). The Japanese call it nikawa.

 

The Japanese have another resin they use to hold ito onto the tsuka called matsuyani that is basically just pine resin I think. Have some of that too, probably pretty similar to the chasing pitch, I would think. This is also used to glue the blade of a kozuka in.

Hide glue shrinks a lot as it dries, which doesn't make it a good filler. That's why resin or tar based mixes are better in that case, as there are no evaporating elements. It just needs to be a mix that's not too brittle and not to soft at any application temperature. Some mixes I've worked with will turn soft on a hot summer day. Particularly additives like wax or fat can lower the melting point quite a bit. 

[Jeroen Zuiderwijk]

15 hours ago, Geoff Keyes said:

Laakh appears to be Lac, as in lacquer, the real bug based stuff.  That makes sense, but more work than I want to go through for this piece.  I have some old American pieces that are cemented into the handles (sliver and ivory) and when you heat it, it smells like pine and bees wax (and sometimes animal dung).  Still holding strong after 100+ years

 

 

Geoff 

Yeah, I found that out as well, basically shellac in unprocessed state. I still have a jar of shellac that I'm not using for anything. I may do some experiments with it someday

[Al Massey]

I usually use about a half-pound of beeswax, a half pound of pine resin aka pine pitch, and a handful of metal dust/sawdust. Melt together slowly, should become a glossy black colour.

Fill the cavity with it but not quite all the way full, roughen up your tang, and warm up the tang with a torch and with your hands protected push it in. Hold still till it sets, usually a minute or two.

 

[Alan Longmire]

9 hours ago, Jeroen Zuiderwijk said:

basically shellac in unprocessed state.

 

Well, since I have a bag of seedlac (raw unprocessed shellac), I did a bit of research into shellac as an adhesive resin.  Turns out it's excellent stuff, much harder and higher melting temperature than pine resin.  I had forgotten that a paste of shellac and wood flour (very fine sawdust) was used hot to press 78rpm records.  Adding wax increases the melting point, too.  So I'm guessing laakh is just a cutlers resin using shellac instead of pine resin.  It'd be nice to know what filer was used.  Those tulwar (and shamshir) hilts with a stub tang set in a hollow metal grip last hundreds of years without losing the blade, so you know it's good stuff.  I do know that the metal was sometimes lined with cotton or linen fabric.  I have a tulwar hilt some vandal (or philistine, take your pick) used to make a decorative picket fence by melting out the resin and mig-welding the loose hilts onto square tubing.  It shows the brazed construction of the hollow grip and the remnant of the cloth lining.  A friend found a pile of them in an antique store in Colorado.  I showed it to Jeff Pringle at a hammer-in once and I thought he might cry...