DIY Blue Spotting Blues!

Could be! The best part was that the guy went to work in the grinding room sharpening pipe facing tools, clamped on his hard hat, noticed nothing unusual, then slipped and ground a divot in a finger, went to first aid sat down for treatment and tool off the hardhat, and the male nurse attendant saw the mess on his forehead and was shocked by what he saw! OMG, what happened to you? He was never sure who did it, even though he may have suspected me. Many years later, at a wedding where his niece was getting married to my nephew, I 'fessed up, and took a hard punch on the shoulder, but it was worth it! RIP Dick Lenz, fellow apprentice ---
 
Richard King 2 said:
Bluing Pic. I also started thin spreading the Canode mix with hard roller brayers
Click to expand...
Firstly - thank you Richard for your expansive contribution, and the pictures. Everybody here knows (or has reasonably suspected) that I am an absolute beginner at this art, and I am pleased to be in a forum where I can so easily get communicating with perhaps one of the most expert and experienced on the planet!

Also to Mark @homebrewed for the (somewhat sneaky) route to the Canode ingredients. I feel should have thought of it too, but I didn't. It shows that using an emulsifier is part of the trick. Of course, emulsifiers is the way most greases end up as water washable. Are not detergents, soaps, washing up liquids, basically emulsifiers? At some stage, emulsified fats and greases have to drop out of the water, making things like the 15 tonne 40m long fatberg in London sewers (2013). I guess my contribution to (old) Hampshire would be stained blue!

Latest try with "low fat spread"
Try not to laugh! No tech or clever chemistry involved. So parochial, it was done on the desk right in front of me. In the way of blind experiment. I think it is a concoction of hydrogenated vegetable oils, mixed with culture-grown stuff taken from real butter to give it the flavour, and perhaps a little yellow (ish) food colouring. AKA "I can't tell it's not butter" ???
What it does do is stay as a soft self supporting stuff at room temperature, without melting.

It becomes blue easy enough. It washes away too, though I have yet to let any of this stuff get past the disposable gloves. It also does not work!

I tried it on the scratched side of my 6"dia x 1" optical flat. It can seem to spread, but not easily get that uniform thin layer. When I try putting a V-block down on it, and move it a little, it hangs onto itself better than to the metal, clumps and streaks. Even if just a little ad-hoc experiment, I think we call this one another bust!
 
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I've used the SDS trick in the past to determine if I could make my own version of something (or to look for nasties I don't want to be exposed to). Very much in line with my handle :). However some SDS's are more specific than others so it helps if you know a little chemistry.

Delving a bit more into the SDS for Canode, Googling "sulfonated oil" immediately found a hit: sulfonated castor oil. It's supposed to be water soluble --- and apparently fairly safe, since it's used in cosmetics......

And just for Graham: A UK source. Amazon sells it, too.
 
"Turkey red oil." Once it's spread thin enough for spotting I bet it's pretty much colorless. For that same reason, I think it likely you will need a fairly high concentration of your blue colorant in order to see it properly. If it's oil based, maybe the emulsifiers are there to take care of the pigment rather than the sulfonated oil? Dunno, you'll just have to try it :)
 
Castor oil, if you look at the chemistry, is a glyceride. It has a glycerol 3-carbons base. The difference is that each carbon can link on a string of fatty acids, but at the root, it is still glycerine, which may be the thing that makes it water soluble. Sulfonated castor oil was, apparently, the first synthetic detergent. Red turkey oil has so many uses, it is widely produced. Thanks for the link. I have some on it's way.

The pthalo-blue is that "brighter" blue as in Canode, and is a common pigment. In paint, for artists and otherwise. Easy enough to get eBay and Amazon hit if it's in a tube with a drying oil (linseed?), which we don't want. Actual powder is not to be seen. I may come across it eventually. I don't really want to have to get at some by washing the oil out of a tubes-worth of artist paint!

[Edit: Strike that - the same place that sells the Red Turkey Oil also has Pthalocyanine Blue Pigment --> The Soap Kichen ]
 
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All edible fat molecules combine a glycerol backbone with fatty acids, so the castor oil isn't the trick -- it's just as immiscible in water as, say, olive oil. It's the reaction with sulfuric acid that alters its "relationship" with water.

The classic way to make soap is to combine oil with a hot solution of lye, sodium hydroxide (NaOH). I've made soap this way, just for fun. The lye reacts with the fatty acids to form a fatty-acid salt and releases the glycerine back into its 3-OH alcohol form. Basically the Na part of lye goes with the fatty acid and the OH part goes with the glycerine.

Glycerine was an important precursor to making massive amounts of explosives for WW2, and much of that came from making soap. That is why citizens were exhorted to save their used cooking oil for the war effort.
 
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