Burmese thorns.

[emgcr]

Here is the interesting visual story of the Burmese thorns that many of us use regularly. The supplier of finished needles is David Williams Tel: +44 (0) 020 8224 9204. David asks for help as he is now running very short of the purple dye granules/crystals which he uses dissolved in methylated spirits to produce the all important colour. Can anyone assist with a modern product as his traditional suppliers no longer even understand the question ?!

[Orchorsol]

his traditional suppliers no longer even understand the question ?!

What is the question Graham? I've worked with various old-fashioned dyes and pigments in the past.

David's fascinating write-up seems to indicate that the only function of the colour is as a visual cue for correct re-pointing, so I'm wondering how essential it is...

[emgcr]

Yes, you are right, the colour is really only to enable accurate point cutting but this is actually quite critical---I have worked with his grinding machine which is a little exacting. In particular, David has an eye defect which is slowly getting worse thus he needs anything which will aid clear contrast. Other colours no doubt would be fine but he is concerned that the chemical dye should not be injurious to the product whilst also not penetrating the thorn too deeply. If you are able to point him in the right direction that would be wonderful.

The colour difference does seem to assist quick assessment of the condition of the point when sharpening between records for the same reason.

[Orchorsol]

Yes, you are right, the colour is really only to enable accurate point cutting but this is quite critical. In particular, David has an eye defect which is slowly getting worse thus he needs anything which will aid clear contrast. Other colours no doubt would be fine but he is concerned that the chemical dye should not be injurious to the product whilst also not penetrating the thorn too deeply. If you are able to point him in the right direction that would be wonderful.

Yes, I see - by the time we end-users get hold of them, it's just a twiddle in a good quality sharpener, but evidently the sharpening process his end is more variable and critical.

I'll give him a ring and see if I can help - will need a little more info about what he's using at the moment (the photo and solubility in meths aren't quite enough in the way of clues). One possibility is that it's Cadmium based (a lot of the old red dyes were) in which caseit's no surprise he can't get hold of it any more! But the stuff in the photo looks more like common-or-garden red oxide pigment... I doubt it though. (Rubber industry experience from many years ago resurfacing again! )

[clevelander]

Another possibility is using Potassium Permanganate otherwise known as Condy's Chrystals. These have been used to colour timber red to brown, depending on the strength, since victorian times. They can be bought from any decent chemist and are used medicinally to treat athletes foot!
Regards,
Alistair

[Orchorsol]

Another possibility is using Potassium Permanganate otherwise known as Condy's Chrystals. These have been used to colour timber red to brown, depending on the strength, since victorian times. They can be bought from any decent chemist and are used medicinally to treat athletes foot!
Regards,
Alistair

I must admit, I hadn't thought of that, and it does look similar to the photo... Potassiun permanganate is an oxidising agent so I wonder if it would have some adverse (or even beneficial) effect on the wood - although that's largely irrelevant as the treatment doesn't really permeate into the thorn.

Speaking to David, when he took over the remains of the business and stock, he was told the (unlabelled) dyestuff was ordinary fabric dye which would have been available from a hardware store back in the day. From that information I'm still none the wiser despite trying to do a bit of research. Anybody any ideas?

[HisMastersVoice]

Another possibility is using Potassium Permanganate otherwise known as Condy's Chrystals.

It does look similar, the original sample may be a bit faded from age? The new stuff looks a bit more purple.

[Orchorsol]

On checking the chemistry, potassium permanganate is out of the question since it reacts with alcohol.

[clevelander]

On checking the chemistry, potassium permanganate is out of the question since it reacts with alcohol.

That is true. Potassium permanganate is miscible with water. Would that cause a major problem when dying thorn needles?.
Alistair.

[Orchorsol]

On checking the chemistry, potassium permanganate is out of the question since it reacts with alcohol.

That is true. Potassium permanganate is miscible with water. Would that cause a major problem when dying thorn needles?.
Alistair.

I'd predict a much longer drying time compared to methylated spirits, and there might be more permeation as a result - which he doesn't want.

Also, organic material like wood is easily oxidised, so I don't think the potassium permanganate would function as a dye even if a wet process did successfully coat the substrate.

Where's an [old country] chemist when you need one? I know some chemistry but there's an old saying about a little knowledge...

The more I think about it, a proprietary fabric dye (new or old) has to be the way forward!