Thymol replacement

[Dan Pavel]

I am making my own liquid pigments from powder pigments and I am using Thymol as a preserver. Unfortunately it doesn't seem to work - after 1 week or so it ended up with a strong smell. What would be an effective replacement for it?

My liquid pigments ingredients are:
- Schmincke powder pigments
- demineralized water
- fish glue as binder
- Orotan 731K as dispersant
- Thymol as a preserver

Using fish glue as binder is a must for my workflow. The fish glue comes as a semi-liquid solution with the consistency of bee honey and has no smell, even after 6 months from opening the can. It certainly has some preserver included. If the smell doesn't come from the fish glue, then what might produces it?

 

[BobUK]

I made up a jam jar of gum to hold paper labels onto microscope glass slides.
The formula is from an excellent book called
Elementary Microtechnique by Peacock.
A small amount of thymol is used in the recipe to prevent mold growing.
The thymol smell is still there in the glue jar after about twenty years, but vanishes from the labels after a few days when the labels have been applied to the slides. The glue is still as good as the day it was mixed.



I have seen menthol crystals used as a preservative in recipes.
Obviously non of these chemicals are for use in food stuffs.

For anyone having problems sourcing Thymol in the UK have a look for bee keeping equipment suppliers.
Apparently a weak solution is used to disinfect bee hives.


Would it be more productive if you posted this question on an art forum?
Artists would have more experience in mixing pigments.

Good Luck

 

[Dan Pavel]

Thanks Bob for your answer.
The smell my liquid pigment develops is not the thymol smell, it most likely is a bacterial smell. In the beginning, for a few days, it doesn't smell at all.
I'll give menthol a try, probably dissolved in alcohol.
Unfortunately artists mostly use Arabic gum as a binder. They never use fish glue and the fish glue binder is a must for me. It was used in some old photographic printing processes and therefore I posted my question here.

 

[fgorga]

The smell you observe is most probably a result of the decomposition (rotting) of the solution due to microbial action.

How much thymol are you using? Can you use a higher concentration? The effectiveness of any preservative is a function of concentration, so increasing the concentration somewhat might help as long as it does not interfere with your intended use.

Are you storing your mix in a tightly sealed container? Thymol is volatile (which is why you can smell it). Thus, if your containers are not tightly sealed the concentration of thymol will decrease over time.

How are you storing your pigment mixes? Storing them cold will also help slow the growth of microbes.

As for replacements for thymol, the two that pop to mind are benzoic acid (easy to source) and thimerosal (probably harder to source but possibly more effective).

 

[BobUK]

Search results for: 'fish glue'

L Cornelissen & Son Online Shop

www.cornelissen.com

Possibly the best artist ingredients shop in the UK. See link above.

If you read the information on each of the above two products, they come from different fish.

I wonder if it is essential to your process to use a specific fish glue?

 

[koraks]

thimerosal (probably harder to source but possibly more effective).

Likely quite difficult to source indeed since its mercury-based. I assume its use is restricted insofar as possible. It was implicated (contentiously so) for problem allegedly associated with vaccines. As far as I'm concerned, a bogus claim, but there was a massive ruckus about about a decade ago.

What would be an effective replacement for it?

You could ask Calvin Grier. He has done extensive testing with a range of preservatives to preserve gum arabic and gelatin. I expect fish glue will be comparable to gelatin in this context (although purity of the material will make a massive difference). One of the things he notes is this:

The only industrial preservative I tested and found to be effective at lower concentrations with gelatin was Kathon.

I did some googling for Kathon when I first read this (a year ago or so?) and as I recall, I found sources in the petrochemical industry; it was only available in gigantic quantities (something like an entire drum) and costs were high. For the kind of use you and I might want to purchase it for, it was unrealistic. I never looked further; maybe Calvin has a source for it or is willing to sell some.

Good performers in his tests (other than Kathon, which is really effective indeed) were sodium benzoate (see also @fgorga's suggestion) and cinnamaldehyde. Salicylic acid worked well for gum arabic, but not for gelatin. Effective concentrations he suggests are 0.04% cinnamaldehyde, 0.1% salicylic acid and 0.01% Kathon.

Hope this helps in any way. Thanks for reminding me of this btw; it's something I meant to look into, but never did...I should really purchase some cinnamaldehyde.

PS, out of curiosity:

Using fish glue as binder is a must for my workflow.

What workflow is this and how come fish glue in particular is so crucial to it?
I've done a fair bit of messing about with DIY pigment dispersions; one of the things that worked surprisingly well was just Orotan and water, nothing else. Yes, the pigment settles down, but it remains dispersed, so stir thoroughly before measuring the amount of dispersion needed in a formula and it's ready to go.
I admit I mostly use Kremer XSL black at this point because it's just so damn easy - it's literally a matter of adding water...but the range of colors of the XSL range is limited.

 

[MattKing]

FWIW, Thymol is difficult to obtain in Canada. Apparently it is something that if used improperly, can be highly damaging to bee populations, so distribution is restricted to only those who are certified in its use.

 

[Dan Pavel]

Thank you gentlemen for your answers!

... one of the things that worked surprisingly well was just Orotan and water, nothing else.

I've tried it before by adding drops of water-Orotan solution to powder pigment in a mortar while mixing them with a pestle, as it's traditionally done. It didn't work and I gave up. But your answer made me think again and this evening I tried adding all ingredients in a closed bottle and shake it until mixed. It seam to work well and I think the binder may not be really needed in the liquid pigment if Orotan can hold the dispersion. I am using 20 drops of Orotan/50 ml. of liquid pigment. What are your proportions?

What workflow is this and how come fish glue in particular is so crucial to it?

A CHIBA replacement for the multilayer gum bichromate process based on fish glue. The sensitizer in combination with any other binder I've tried, any ready-made watercolor paste or ready-made liquid watercolor mixture stains the highlights in different degrees. If only fish glue and pigment is used it clears perfectly.

 

[koraks]

Ahhh, I understand your application. Very interesting to hear that the fish glue turns out to result in the lowest level of stain. I know that Calvin ultimately resorted to clear interlayers of hardened gum to combat stain. It apparently worked extremely well and was a critical aspect of the colorful look of the examples he made with the technique. However, his work was dichromate-based (which is why he abandoned it after figuring out how to get the job done); I don't think he has done any Chiba/FAC work.

For a watery pigment dispersion, let's assume I'm making a batch of 10g dry pigment (it can be scaled up as desired) and I want to end up with a 10% w/v dispersion. I'll weigh out the 10g of pigment, then add a few drops of Orotan; something like 5 drops will be ample. Then add a little water; I'd use something like 20g or so for this amount of pigment. I do this in the plastic container of a 35mm roll of film; these seal very well as it turns out. I add a few stainless steel milling balls, then put the plastic container within the jar of my cheapskate rock tumbler and let it tumble for an hour or so. After this, I sieve out the milling balls and was the pigment into a beaker, then top up to the volume desired and put it into a wide-mouthed jar. The pigment will settle in this jar, but it can be shaken up before pipetting out the amount needed for a recipe.

Since I use this for carbon printing, I usually add a binder like gum arabic or honey (either or both work fine). But I also no longer make pigment dispersions that sit around; I produce carbon tissue in batches and just make the amount of pigment dispersion I need for that batch of carbon tissue. However, when I was experimenting a lot with pigments 1-2 years ago, I made several dispersions (some I still have sitting around) along the lines indicated above.

I tried a mortar & pestle, but the quality of the dispersion was absolutely horribly bad. A muller works much, much better and gives a reasonably OK dispersion. It also works with just Orotan and a few drops of water, but you need to keep an eye on the amount of water so the mulling works well (too dry and you're pushing around clumps, too wet and you're not dispersing the pigment effectively). The rock tumbler method described above gives far superior results to either the mortar & pestle and the mulling approach. Btw, I didn't make this up; Calvin does it this way and Sandy King et al. also describe a similar procedure in their carbon printing book. Most of my experimentation ends up confirming what others already said before (I just understand better why it works in a certain way, and what goes wrong if I ignore their advice!)

 

[snusmumriken]

Apart from the fishy smell, fish glue is very much like hide glue. Thinking along those lines, it might be of interest to know that Titebond make a liquid hide glue, which I have used, and which I know some luthiers also use. As it is liquid at room temperature and comes in a handy bottle, it is really easy to manage and - as far as I can see - dries completely clear. Can be dismantled using water or steam.

 

[Dan Pavel]

Thanks for the info.

Apart from the fishy smell, fish glue is very much like hide glue.

The fish glue I use has no smell at all, even after 6 months from starting to use it. The liquid pigment starts to smell after a while, but not a fishy smell.

 

[NedL]

...

A CHIBA replacement for the multilayer gum bichromate process based on fish glue. The sensitizer in combination with any other binder I've tried, any ready-made watercolor paste or ready-made liquid watercolor mixture stains the highlights in different degrees. If only fish glue and pigment is used it clears perfectly.

Dan,

As I was reading, I thought that might be what this was about! I know I read somewhere about selective hardening of fish glue with iron salts. I'd be very surprised if the choice of pigment and type of fish glue didn't also affect staining... Good luck! I hope you will consider telling us how it all goes!

 

[Dan Pavel]

Thanks Ned.
Of course I will post the details of the process here when I'll finish adjusting it. I am almost there and till now it's very promising. For me it seams to work as well, if not even better, as the gum print, but my gum printing abilities are not at the highest level.

 

[FotoD]

The fish glue comes as a semi-liquid solution with the consistency of bee honey and has no smell, even after 6 months from opening the can. It certainly has some preserver included. If the smell doesn't come from the fish glue, then what might produces it?

Maybe it's this Orotan thing that is rotting. It apparently need its own preservative (BIT). Why do you feel you need to use it?

I can't say I've noticed any bad smell mixing only fish glue, pigment and distilled water and keeping it for close to a year now. Some pigments have a little more smell than others though.

I've only used thymol for pig gelatin and gum. Very effective there. With fish glue I've counted on the phenol in the glue to keep the bugs away. Seems to work so far.

The fish glue I use has no smell at all, even after 6 months from starting to use it.

What glue are you using, and at what dilution? The glues I've tried have a distinct smell of Sassafras. Are you sure there's phenol in your glue?

 

[koraks]

Maybe it's this Orotan thing that is rotting.

I don't think so. In my watery dispersions that involve Orotan, nothing rots. No preservatives added.

I think you're missing the fact that @Dan Pavel is working with dry/powdered pigments, and that you are referring to pastes, paints and inks as 'pigments' (as evidenced by your reference of pigments having a smell - dry pigments have virtually no scent at all since there's nothing volatile about them). This happens a lot in the alt.process community, but it creates confusion. Orotan 731K is a very effective wetting agent for making pigment dispersions from dry/powdered pigments.

 

[Dan Pavel]

I am using this Kremer fish glue:

with this product information:
"Fish glue is liquid because the fish proteins must function well at water temperatures down to 4°C. Warm-blooded glues all gel at 20 °C at the latest. Fish glue is suitable for all applications where particularly high elasticity must go hand in hand with very high strength. A particular advantage is the great adhesion of fish glue to wood, ceramics and metal. Fish glue can also be used in concentrated form on cold substrates. Our fish glue is cooked from unrotten fish remains, which is why the smell of fish glue is not unpleasant. The 300 g are packed in a PE dispenser bottle."

Its' smell is quite discreet and not unpleasant. I can't tell you for sure what is it like.
The dilution I use is 2g fish glue/50ml liquid pigment.

 

[FotoD]

The dilution I use is 2g fish glue/50ml liquid pigment.

OK. I haven't used Kremers glue yet, but I actually have it on order. I expect it to be a quality product. It contains both phenol and Sassafras. (Someone said that most fish glues come from the same source anyway)

I think you dilute it too much to take advantage of the phenol preservative. And maybe the thymol you add is not ideal for rotten fish?

I mix the liquid glue 1+1 with distilled water and add pigment. That makes about 23% fish gelatin. Your mix would contain only about 1.5% fish gelatin. That also means you have 15 times less phenol in your pigment mix.

Another benefit with the high concentration fish glue is that I don't see a need for a dispersant.

Schmincke Brillantgelb (PY154) has a bit stronger smell than the other colors. But I wouldn't say it smells bad. It could come down to an interaction between benzimidazolone and phenol, but that's just a guess.

 

[snusmumriken]

I am using this Kremer fish glue:
View attachment 381357
with this product information:
"Fish glue is liquid because the fish proteins must function well at water temperatures down to 4°C. Warm-blooded glues all gel at 20 °C at the latest. Fish glue is suitable for all applications where particularly high elasticity must go hand in hand with very high strength. A particular advantage is the great adhesion of fish glue to wood, ceramics and metal. Fish glue can also be used in concentrated form on cold substrates. Our fish glue is cooked from unrotten fish remains, which is why the smell of fish glue is not unpleasant. The 300 g are packed in a PE dispenser bottle."

Its' smell is quite discreet and not unpleasant. I can't tell you for sure what is it like.
The dilution I use is 2g fish glue/50ml liquid pigment.

Photrio is an education. That difference in gel temperature seems obvious when pointed out, but it had never occurred to me. Glad I followed this thread.

 

[koraks]

benzimidazolone and phenol

Benzimidazolone has a slight phenolic scent without any additives. It's the only pigment I've tried so far that has a bit of a noticeable smell. It's not unpleasant.

 

[Dan Pavel]

I followed Koraks' advice of using a muller and made some water/Orotan/pigment only suspension. It worked quite well and wasn't so difficult to make. It should work OK, I am sure, and no preserver should be needed.

I've tested before emulsions made of fish glue + powder pigment + water + Orotan + sensitizer and they worked well. In fact, the need of liquid pigments appeared mainly from the the difficulty of measuring correctly the tiny amount of powdered pigment necessary for a single small print, as the test prints are, and the need to ensure identical recipe for all prints, regardless of size (In the tests stage I only use fresh emulsions). Therefore some not very concentrated liquid pigments are much easier to use.

 

[FotoD]

difficulty of measuring correctly the tiny amount of powdered pigment necessary for a single small print, as the test prints are, and the need to ensure identical recipe for all prints, regardless of size (In the tests stage I only use fresh emulsions). Therefore some not very concentrated liquid pigments are much easier to use.

Yes, measuring dry pigment for a single small print is no fun. I find it convenient to make a stock dispersion of pigment and binder, and then using it by the drop for single prints.

Hope your pigment mix will work well.

 

[BobUK]

I followed Koraks' advice of using a muller and made some water/Orotan/pigment only suspension. It worked quite well and wasn't so difficult to make. It should work OK, I am sure, and no preserver should be needed.

If you are looking for a cheap muller, have a chat with the local stone mason.
The bases that support the headstones in graveyards often have a hole bored in them about 5" diameter. Into this the vase for flowers is placed.
The hole is bored out with a core drill, leaving a solid cylinder of waste marble, with polished top and bottom faces.

According to the book I read, they make good cheap, often free mullers.

 

[Dan Pavel]

Thanks for the advice, Bob.

 

[ced]

Look around for glass stoppers at the flea markets some are easily turned into mullers. https://www.truevintageantiques.com...t-sizes-and-shapes-all-ground-glass-stoppers/
Sodium Benzoate & or Clove oil for preservative.

 

[Dan Pavel]

Thanks Ced. I ordered a small 35mm muller from Kremer for only 16,07 €. Till it arrives I used the glass of an old 55mm skylight filter glued to a plastic cylindrical handle as muller. It worked very well. As a working surface I used some very cheap large round laboratory glass plate intended for bacteria cultures. I recommend it for smaller quantities of paste. It's perfect for the job as it doesn't let the pigment paste to make a mess all around.