Friday, 10 February 2012

Gum Tragacanth

Another week , another exciting slice of shoemaking life.

It started off brilliantly with a great Eclectibles page in  How To Spend It in the Weekend Financial Times which featured our brown, Go Faster Stripe lizard shoes. They looked fantastic and we're included on the Contents page and website as well. So a great big thank you to Philippa Clark who puts the feature together

And so to shoemaking, specifically finishing the soles and top pieces. With a black finish, there is no ambiguity - you simply apply black ink, polish, burnish.

But if you want a natural finish, then you have to work a bit harder.

When we were apprentices, our master, Paul Wilson, used to use a solution what he called Gum Dragon. This was applied directly to the sanded sole before you applied the polish. It has the effect of hardening the sole, so that when you apply the polish, it does not go smeary and uneven. After we finished our apprenticeships, we did not have the recipe to make it, so we simply used water instead. This has a similar, but inferior effect.

So I decided to sort it out and get some Gum Tragacanth, as it is more correctly called. And where did I find it? Our good friends at Cornelissen of course, where else?




But buying the stuff was the easy bit. Next I had to find a way to prepare the solution, so I turned to one of our shoemaking bibles, The Shoe Finishers' Guide by W D John, a marvellous book published in 1934.


And here is what it said about Gum Tragacanth.

It is a gummy mass which exudes from a shrub found in Greece, Turkey, Syria, Iran and Kurdistan. The stems are cut and the gum comes out and hardens into flakes or lumps. This is then collected 3 to 4 days later and sorted into grades. The type of cut on the stems determines the kind of gum collected.

It is chiefly used in the manufacture of confectionery and medicines, but just a little is available for the likes of us.

It resembles dry horn or nail and comes in dull off-white contorted flakes which tend to powder over time.

When it comes into contact with water, it swells enormously and absorbs forty times its weight in water. The resulting mucilage is fairly revolting and consists of two parts - a slimy opaque jelly like liquid and a solid part called bassorin which can be filtered out.

The recipe we used was the following

3ozs gum tragacanth to 1 UK gallon of water, mixed and left over the weekend. Filtered and finished with 7ml of 40% formaldehyde. A word of warning though. Formaldehyde is nasty toxic stuff, so you must wear protective gloves and use it outside to avoid breathing it in. DANGER!

1 UK gallon of water

The resulting mixture separates into two parts, the liquid on the bottom and the solid bassorin on the top.





We then filtered out the bassorin.



We added the formaldehyde outside with gloves on using a syringe, and stored it. We have enough for a lot of shoes. I have a feeling it might be a bit thick, so I will test it out and might have to dilute it a bit with water.




And that is that. We have not tried it yet, but are expecting natural soles with the cleanest, smoothest, most even finish you can hope for.

When we have a newly finished sole to compare with an old one, I will post some pictures - I got a bit excited about this, so had to share it with you before having a 'before and after' shot to show you. But it will be here shortly, never fear.

And that, as they say, is a wrap.

Guess what we are going to write about in next week's post? Let's just say that Johnny Depp will be looking over his shoulder soon enough.

Until next week, happy shoemaking!