Kresto® Kolor ULTRA
In my earlier Paraphernalia post I mentioned “Reduran Spezial hand cleanser”, which I hadn’t tried. I found it at a reasonable price on eBay UK and ordered it on Saturday. It arrived on Monday morning, well-packaged. Good job,
rapidontheweb, that’s ridiculously quick for eBay.
“Removes dye soiling caused by toner, azo dyes, aniline, printing and copying inks, and fruit and vegetable colourants; contains a reducing agent.”
I must say, it wasn’t entirely easy to find. Searching for “ReDuRan® SPECIAL”, or “Reduran Spezial”, etc. isn’t entirely helpful. The tube that arrived is known as “Deb stoko Kresto® Kolor ULTRA” “Specialist” hand cleanser, which appears to be its (current) name in the UK.
Anyway, I thought I’d give it a go. Let’s dive in at the deep end with the notorious Noodler’s Baystate Blue.
Right… a dollop of the Kresto and some scrubbing. It’s beige and gritty. No bad smell.
“Converts reducible dyes into their uncoloured form, enabling them to be readily washed off the skin.”
Apparently the reducing agent counters many dyes, which are often acidic… thinking back to my chemistry, acids are oxidising agents. If I remember correctly, most common fountain pen inks use azo dyes and anilines. Not sure about diamines, which I think are derivatives of anilines. I do know that many food colourings are acidic, as well as a lot of textile dyes. I’m not sure about Procion MX and other fibre-reactive dyes that might be used in “Bulletproof” inks.
So, I’m guessing this stuff is slightly alkaline, buffered or something like that. However, as far as I know Noodler’s inks are sometimes alkaline, so maybe Baystate Blue isn’t a fair test.
(UPDATE: yeah, slightly alkaline, pH = 9. See the end of this post for more information)
Not bad! However, I’m fairly sure this was more about exfoliation than chemical reduction. I must admit that as a manly man I don’t exfoliate religiously, so my hands aren’t baby-soft.
“Contains Astopon® natural scrubbing agent […] produced from refined walnut shell powder, a natural and renewable source.”
Let’s try again.
In the process of taking this photo, time stopped for me and I almost had a heart attack. I knocked the vial of Baystate Blue off the side of my desk and onto the carpet. It was like watching a live grenade fall next to you. Fortunately, the cap (while loose) was tight enough to stop any spillage. Crisis averted.
Okay… to the sink.
As expected, not much change. Wash with liquid soap and warm water.
To be fair, the Quink’s on its way out, but from experience I know it’ll take some time (and moulting) before it really goes away.
Here we go with the Kresto.
Normal hand-washing with the gritty Kresto:
Here I’ll pull out the power tools. What’s basically an oversized electric toothbrush that I got from Lidl for scrubbing the bathroom tiles.
So yeah, it looks like this cleaner works well on the inks I tried. However it is not as chemically effective on Baystate Blue, but is useful mechanically as long as you maintain a good shield of dead skin as a defence.
Final boss level: Gentian Violet
Gentian Violet is a moss-green crystalline dye that makes for a vivid violet purple ink. There are many green-sheening violet inks out there that I believe are probably based in part on Gentian Violet. In fact, I think Cult Pens’ Robert (as tested above) uses Gentian Violet, and I suspect some of the Krishna inks I have use it. It’s a component in a lot of blue and black inks for printing, ballpoint devil sticks, and inkjet ink. It’s also great for dyeing babies purple; seriously… click it. Hilarious.
Now I know that this goes colourless in alkaline conditions, but I’ve never tried it as I’m not the world’s biggest fan of chemical burns. However, after using it on one of my toes to see if the antifungal thing worked, I’ve had a purple cuticle for about six months. I’ve also made a hell of a mess with this stuff, making me regret buying a half-kilogram of it on eBay late one night. That could pretty much dye the county purple.
From experience I can tell you that soap and water won’t help here. Let’s try Kresto.
After all this, my hand’s a little raw, but not too bad. I have relatively sensitive skin, but it hasn’t broken out too bad yet. Being a reducing agent, I think it’s definitely best to make sure it’s washed off well after use, perhaps with a more-traditional skin-safe soap. And I’d recommend getting some Palmer’s Cocoa Butter Formula or O’Keeffe’s Working Hands Hand Cream for application afterwards, and my hands are now feeling fine (and smell nicely chocolatey)
Now I’m going to go sprinkle some vinegar on my hand and see what happens.
UPDATE: Yeah, a spray of limescale-removing bathroom cleaner – contains phosphoric acid – got rid of the remaining Baystate Blue, and probably what’s left of my epidermis.
So what’s in it?
I checked the Safety Data Sheet, and it includes:
- PEG-8 (probably for several reasons, eg. viscosity, humectant)
- LAURETH-10 (emulsifier, surfactant; ie. soap)
- SODIUM HYDROSULFITE (ie. reducing agent)
- JUGLANS REGIA SHELL POWDER (ASTOPON®)
- PEG-2 RAPESEEDAMINE (more polyethylene glycol, this time from rapeseed oil.)
- SILICA (as an abrasive, possibly)
- PROPYLENE GLYCOL (not the same as the polyethylene glycol above. A humectant, solvent, preservative, although I don’t know its purpose here. It’s sweet, edible, and can be used to make fountain pen ink “wetter”. Ironically, the American Contact Dermatitis Society’s Allergen of the Year for 2018)
- TETRASODIUM EDTA (stabliser, maybe?)
- HYDROXYETHYL ETHYLCELLULOSE (gelling agent?)
- TITANIUM DIOXIDE (white pigment; used in paint, sunscreen, and toothpaste)
- SODIUM PHOSPHATE (thickener? emulsifier?)
- PARFUM (FRAGRANCE) (stink!)
So, the reducing agent is sodium hydrosulfite a.k.a. sodium dithionite, or “Reductone”; a reducing agent.
“This compound is a water-soluble salt, and can be used as a reducing agent in aqueous solutions. It is used as such in some industrial dyeing processes, primarily those involving sulfur dyes and vat dyes, where an otherwise water-insoluble dye can be reduced into a water-soluble alkali metal salt (e.g. indigo dye). The reduction properties of sodium dithionite also eliminate excess dye, residual oxide, and unintended pigments, thereby improving overall colour quality.”
and with the Laureth-10, the PEG-8, the silica and titanium dioxide, it’s not far from being toothpaste, albeit rather more abrasive than usual.
…and it’s pH is 9 in diluted solution (100 g/l, @ 20 °C), so a bit alkaline as I suspected.