Question for chemists about improving Canode spotting compound for scraping

[J Tiers]

Canode is easy to clean up, but unlike the HiSpot blue, it tends to dry out and become hard to work with. Canode is water base, HiSpot is grease based. The Canode tends to become a sort of chalky sludge that does not have the really nice marking characteristics of HiSpot blue.

I am looking for something that is reasonably available to normal folks and which would reduce or significantly slow Canode's drying. Just re-diluting it in water does not do well, since it makes the material "smeary", too liquid, and not very suitable as a marking material.

The reportable materials on the SDS for Canode are given here: https://www.msdsdigital.com/die-spotting-blue-2243-msds

The important one seems to be Nonylphenol Ethoxylate given as 20%, which seems to be the thickener, since it is described elsewhere as a "viscous liquid", and the 295C boiling point suggests that it is not very volatile.

I was initially given propylene glycol as a suggestion, which is available in some antifreeze, and is not that toxic, although it will dry out, making it not ideal. Another suggestion was polyethylene glycol, but that is supplied as a powder, not a liquid, and would still dry out. Adding more Nonylphenol Ethoxylate might be effective, but it is not the nicest stuff, and I have no source for it.

Any other ideas for something that would be compatible, and perhaps more viscous so as to potentially carry the pigment better, and act more like the grease based HiSpot blue?

[nc5a]

JT

The cheap and dirty but effective answer is mix a little windex in with the glob of canode when spotting. I also add a "little" water to my canode bottle from time to time and keep the cap screwed on tight, so far I haven't had any problems. Yes, it gets gooie after a time but a little shot of windex makes everything better.

[J Tiers]

Windex does make things better, for 20 seconds.....then back to normal. It gets VERY dry here in the shop. Just a little too much windex and the Canode is smeary, then there is 10 to 20 seconds of good, and after that back to not so hot. I even put plastic over the reference surface between spottings, both to keep it clean, and to keep it from drying.

I'm looking for maybe 30 minutes of decent performance. By then I'll be ready to clean off and re-spread the Canode.

[nc5a]

Sounds like your applying the spotting to thick. During the final stages of scraping I use yellow and blue and easily get 20 to 30 minutes use when cut with windex. You should be able to see the color variations in your surface plate through the spotting compound.

Like this

And this blue canode at the top of the photo

[J Tiers]

It ends up too thick and I have to clean it off often to avoid that. About every second spotting, or even every one. "Thin" in this case I mean as how viscous it is.

I do not put it on too thickly, though, I use a dauber, not a brayer, and it gets as thinly spread as it will go. But that never seems to be as thin as I would like, it seems to dry out and stop spreading well before it is fully spread. Turns into a chalky sludge.

I have never been able to get it to fade out the way HiSpot does. Nor does it do what I see in your picture. But if I thin it, it gets too liquid and smeary. A puzzlement. Hence my interest in thinning it with something that will not dry quickly.

HiSpot works like I do.... as I begin to need it thinner, it gets thinner, all the way to a haze when I want that.

When Canode is anywhere near that thin, it is very dry and barely marks anything, and that not very consistently. Almost might as well be rubbing chalk on as marking compound. Have been using it for a while, and still do not like it, except that it is cleaner to use.

I would suspect it to have dried in the bottle, except that it seemed that way right away when I got it. Got it from ARTCO, who seem to sell plenty, and it should not have been old stock.... maybe it was???

[nc5a]

I've never seen the chalky surface you speak of and I've been scraping for 20 years, not full time or professionally mind you but still somewhat active. Try some new canode and windex if you need to thin it and try a brayer for kicks.

[J Tiers]

I've never seen the chalky surface you speak of and I've been scraping for 20 years, not full time or professionally mind you but still somewhat active. Try some new canode and windex if you need to thin it and try a brayer for kicks.

No brayer... it puts stuff on too thick.... was no good even with HiSpot blue. And, it also does not clean off particles, the way a dauber does. tried it, do not like it at all.

Windex does not seem to work well.

I really may go back to HiSpot blue,,,,, it J F works.

I'm not pro either, but I have done it for pay.

Before I give up, we'll see if any of the chemists here have any good suggestions.

[Alan Smith]

Glycerin is often added to substances to delay drying, or at least help retain moisture. Might be worth a try?

[markx]

One could also use vegetable glycerol (+water if needed) as the solvent for the spotting dye. Glycerol is 1,2,3-propanetriol in a chemical sense and related to the other polyols/glycols that are used in antifreeze. It is viscous, hygroscopic and totally harmelss unlike ethylene glycol which is poisonous. It should not dry out too quickly, as it also displays hygroscopic properties. Might be worth a try.

Nonylphenol Ethoxylate is not so much a thickener, but more a surfactant and emulsifier (detergent like substance). Added to a composition it will make substances that are usually not miscible with water (like oils and other heavy greasy organics, also organic dyes) become soluble and miscible in the mix. I suspect that it is the main role of the substance in the composition of the spotting dye: make the mix water miscible, so it can be declared as a "water based" formulation. In light of that you could also try to dilute the dye with greasy solvents like castor oil, linseed oil or other liquid fatty substances. They might be miscible in the mix due to the action of the nonylphenol ethoxylate.
If it does not work straight up then one can go a step further and add extra surfactant + oily solvent to the composition. Like dishwashing detergent concentrate + castor (or some other) oil. Dishwashing detergents are quite powerful and make all kinds of oils dissolve into water. Even light mineral oil could be used. That kind of a mix will definitely not dry out, but there could be other side effects like possible clumping or separation of dye. Just sayin' .....
So do some experimentation on the stuff and hope it works out!

You can even try to formulate your own spotting dye from scratch and tune it to your specification if you are interested in the topic and like to experiment. There is really not too much to it and ordinary components can be used.

What you basically need is.....
An organic dye: prussian blue, methylene blue or other contrasting dyes can be used
A carrying medium/body of the formulation: oily base, a mix of oil+detergent+water, water+glycols, just glycols, or a combination of all the former
A solvent to adjust viscosity: light mineral oil, water, glycols, heavier organic solvents (naphta like fractions that do not evaporate so quickly)

Prussian blue pigment and other dyes are available in pure form and one only needs a tiny bit to color a huge amount of formulation. That also goes for all other organic dyes.....they are incredibly strong and a tiny bit can color a huge amount of stuff. Just watch out when handling the dyes in dry and pure form. If you spill these or get them on your skin or the dust becomes airborne, then the whole surrounding area is contaminated and will smear everything that comes to contact with it. It can be impossible to clean up properly. A huge mess can result
Also it is wise to choose a dye that is actually soluble in the main body of the spotting compound: an oil based formulation should use oil soluble dye and a water based formulation should use a water soluble dye. If the dye is actually soluble in the formulation, then a really thin and accurate marking can be achieved, as there are no particles or clumps of dye that could distort the result.

I see in the MSDS of the original formulation that titanium dioxide is included....this is a white powder that is used as a contrasting carrier for the colored dye substance. It is also not soluble in anything and responsible for creating the white chalky appearance when the formulation dries out. Also it will increase the layer thickness and distort the result of spotting to some extent. If a soluble dye is used then this kind of a problem shall not arise.

Happy experimenting!

[batt-man]

Just going to throw this out there - have no idea if it'll work

Go to your local artists shop and look for acrylic paint retarder - my wife uses this particular brand but there's others out there as well

https://www.cassart.co.uk/painting/acrylic_colour/product_type_medium/golden_retarder.htm

She does a fair bit of acrylic artwork and likes it pretty warm in her studio (one of our spare bedrooms) so paints tend to dry out on her fast - this helps enormously.

As i say i have no idea if it'll work but might be worth a shot...

Cheers
Batt

[Sparky_NY]

No brayer... it puts stuff on too thick.... was no good even with HiSpot blue. And, it also does not clean off particles, the way a dauber does. tried it, do not like it at all.

Windex does not seem to work well.

I really may go back to HiSpot blue,,,,, it J F works.

I'm not pro either, but I have done it for pay.

Before I give up, we'll see if any of the chemists here have any good suggestions.

One guy gets bad results, one guy gets good results. The guy with bad results rejects every suggestion the guy with good results gives. Whats wrong with that picture?

(I suspect the guy with good results is not unique in his methods and materials, the process is as old as dirt)

[Peter.]

I put in a little tap water and it thins it just great. Not the most recent stuff I bought though I've had to send that back.

[Doozer]

I know it is not the same, but...
I just discovered the king size Sharpies
that are about 1" around. I have a red one
and for small high spot finding, it works pretty well.
They don't totally suck like the regular size Sharpies.

-Doozer

[Dan_the_Chemist]

Canode is easy to clean up, but unlike the HiSpot blue, it tends to dry out and become hard to work with. Canode is water base, HiSpot is grease based. [snip]

I am looking for something that is reasonably available to normal folks and which would reduce or significantly slow Canode's drying. [snip]

I was initially given propylene glycol as a suggestion, which is available in some antifreeze, and is not that toxic, although it will dry out, making it not ideal. Another suggestion was polyethylene glycol, but that is supplied as a powder, not a liquid, and would still dry out. Adding more Nonylphenol Ethoxylate might be effective, but it is not the nicest stuff, and I have no source for it.

[snip]

My first thought was that anything that is water based will eventually dry out. No matter how tightly the other components of the mix hold onto the water there will always be a small but appreciable amount of water vapor escaping from the surface, and any air movement will cause it to dry out.

However, upon further thought I realized that isn't quite true. If the room is kept at 100% humidity the amount of water escaping from the Canode will be replaced by an equal amount of water condensing into the Canode from the air. So that's one answer. Seal your shop and use misters like Orchid growers use.

But more importantly, the rate of that drying out can be retarded. Some materials are notorius for being very slow to dry... among them, certain gelling agents and many carbohydrates. For example, consider honey. Simple sugars hold onto water tenaciously. Some one has already mentioned glycerine, which is almost a carbohydrate. It is used to hold moisture and prevent crystalization in candies, face creams, etc. It also has the advantages of being non-toxic and cheaply available (pharmacy). Or corn syrup. Add a few drops of corn syrup that has been lightly diluted with water.

Or you may want to take advantage of the results of a related field of engineering. There is another field where people wish to reduce friction with a non-toxic, non-corrosive material that doesn't dry out too quickly. One of the products produced for that activity is called KY Jelly, and is also available at your pharmacist. It comes in a jelly and a dispensible liquid form. If you look at the list of ingredients for liquid KY Jelly you will find glycerine, propylene glycol, sorbitol, and hydroxyethyl cellulose for lubrication, with benzoic acid, methylparaben as preservatives.

While you are at the pharmacist you might want to buy some nitrile gloves to prevent your hands from being stained by the Canode. You might find that old wooden clothes pins are useful around the shop, as well as some rubber tubing and clothes line. Rubber squeeze bulbs (sometimes used for enemas) are useful for blowing chips and dust away from delicate work. Buy all of that at once along with a half gallon of KY and you'll be the talk of the town.

[J Tiers]

Interesting suggestions, will try as I get the chance. The propylene glycol is looking good, as it is probably the most available. If not good, will move on tot he next. Thanks for the suggestions.

I don't expect to make my own, just to get the Canode to work better for me. I could actually have a bad batch, but I dunno if I will bother to order more on the off-chance that is true, might get another bad batch.

Meanwhile I can use it, I just have to keep cleaning it off and re-applying.

One guy gets bad results, one guy gets good results. The guy with bad results rejects every suggestion the guy with good results gives. Whats wrong with that picture?

(I suspect the guy with good results is not unique in his methods and materials, the process is as old as dirt)

And another guy, who JUST POSSIBLY MIGHT have had a suggestion worth reading, is again, not helpful, just bitching as usual, NO positive intent whatsoever. Won't bother reading next time.