The Crispin Colloquy

Hirschkleber is made from potato starch. It dries nice and hard, but will re-soften if wet.

I've never found anything I wanted to use for gluing the channel cover down on the outsole. All Purpose works good at first (till the shoes get out the door) but it quickly de-laminates and then the channel cover is flapping in the breeze. And what's more you have to deal with the fumes. Everything else has to be clamped. maybe a sole press and celluloid cement would work but it would have to press that cover pretty closely and tightly.

I have never seen any antique, elderly, vintage, angled channels with glued-down flaps that ever stayed shut. Even in the waist they'll grin open after a while. The flaps all come loose and go to rags in wear, at least at the toe and around the forepart. Angled, flapped channels, seem to have started out on women's fine dress shoes, mid-late 1700s, often worn with protective overshoes when venturing outdoors. Don't recall any on men's soles until later 1800s. For men's shoes/boots, prior to that period, they are all vertical channels (like a Landis stitcher knife cuts), hammered shut from paning the sole edge and rasping smooth to hide the channel. In the 1700s, the "best" (so said most everybody in 'The Art of the Shoemaker' who commented on it) were the English-style, stitched "aloft"--no channel, no groove, just thicker thread stitched finely. IOW, the exit-side of the stitching (visible) on the bottom of the sole had to look as neat and perfect as the entry-side of the stitch--no easy feat.

Just over the weekend I experimented a bit with cooking up my own paste.

From what I understand potato starch itself does not stick well but has to be converted to dextrine first. So I have spread the white potato starch powder on a tray and baked it at 150 Deg C for four hours and stirred it occasionally in the meantime until it was yellow. If you mix that yellow powder with water you will have a nice paper glue already, but this one is too brittle for leather applications.

Like @das mentioned somewhere else, I also read that shoemakers traditionally seem to have only used gluten paste based on rye flower. Some sources state that you only need to pour boiling water over the flour and mix it well, other sources I found state that you should mix Rye flour with water and boil it well for five minutes. Using only that paste, I also had the impression that HK was still superior.

However, since I still had a good part of Dextrine powder left, I thought: Why not mix it into the boiled rye paste? The ratio was more or less 2 parts rye flour + 1 part dextrine. And viola, it sticks really strong after drying. (For testing I bonded the flesh side of a lining sample to the flesh side of an upper leather). Fairly comparable to HK, I would say. Except for the color - mine is a bit darker than HK, the only difference I see so far is shelf live. HK - states on the container that the paste does not ferment - now having been looking at my paste I know why. I guess in HK the 4-chlor-3-methylphenol (also indicated on the container) prevents fermentation. Apparently this stuff is often used for disinfection. My paste had developed some air bubbles after three days at room temperature. Not sure yet how the bonding power is affected by that yet.

Wow, next up you will be growing your own thread ;-) I saw someone on IG that has actually sown a patch of flax for this, incidentally. The only thing I don't like about HK is the smell. Did your paste smell any better?

Hah - and I thought YOU are into gardening and growing your own food.


I guess for hemp thread one would even need to grow canabis - but that is much beyond my ambitions...

Well, my paste doesn't smell like roses either, but when freshly made I think it smells nice and even after a couple of days at room temperature more pleasant than HK. Not sure, maybe one has to keep it refrigerated or only make few amounts when needed.

I am told (ahem) it's a different cannabis that's used for *that* ... apparently fibre hemp is super easy to grow, almost all of it is organic for that reason, no need for pesticides, fertiliser etc. The tricky bits would be retting, drying, hackling, spinning, all in all probably a fool's errand unless you are doing it for fun and to experiment. Get it wrong and it;s no good even for smoking ;-)