Iron Gall, Preventing Mold Etc.

[linearM]

I walk in the college arboretum every weekday and noticed oak galls on some of the smaller oak trees. Hmmm, maybe I should try making some iron gall ink! That is what started it all. I looked up recipes, found one that was simple enough and got the iron sulfate and gum arabic and now have a batch of iron gall ink that I am really enjoying using...with my dip pen not my vintage fountain pens. This is my first venture in making my own ink but may not be the last. I have a black walnut in my front yard!

 

Now I'm wondering if I might have problem with mold growth or some other slimy organism fouling up the ink. Is there a preservative that I should be using to prevent the problem, or maybe with the acidity that iron gall is supposed to have organisms aren't a problem. I think I saw someplace that cloves could be placed in the container and would do the job. Any suggestions or comments would be appreciated.

Edited April 26, 2017 by linearM

[LizEF]

I don't know the answer to your question (though I remember reading something on these groups about phenol, so you might want to research that). However, I work in a microbiological testing lab (but I'm in IT), and we make our own media for growing organisms as part of the testing. The media recipes include what the pH of the media is supposed to be. Since the media is bug food, you gotta figure the pH is that preferred by the bugs (I'm making assumptions here). If that's the case, the acid won't keep everything from growing - we have media at pHs from 3.45 to 10.5. Now the big question is whether any of the applicable organisms are probable in the environment where your ink lives.

 

My googling says iron gall ink has a pH from 2 to 5. Below is a list of organisms we verify will grow on media with a pH less than 6. The problem with this list, of course, is that it may not include everything you should be preventing (because the work we do may not have a reason to test for those organisms). If nothing else, running a few queries was mildly entertaining to me...

• Aspergillus brasiliensis ATCC 16404
• Bacillus atrophaeus ATCC 9372
• Bacillus atrophaeus MDT/CASTLE
• Bacillus subtilis ATCC 19659
• Bacillus subtilis ATCC 6633
• Bacillus subtilis NAmSA
• Bacteroides fragilis ATCC 23745
• Bordetella bronchiseptica ATCC 4617
• Brevundimonas diminuta ATCC 19146
• Burkholderia cepacia ATCC 25416
• Candida albicans ATCC 10231
• Clostridium sporogenes ATCC 11437
• Corynebacterium xerosis ATCC 373
• Enterococcus faecalis ATCC 29212
• Escherichia coli ATCC 8739
• Escherichia coli C ATCC 13706
• Geobacillus stearothermophilus ATCC 15951
• Haemophilus influenzae (Q1)
• Haemophilus influenzae (Q2)
• Haemophilus influenzae (Q3)
• Haemophilus influenzae (Q4)
• Klebsiella pneumonia ATCC 4352
• Klebsiella pneumoniae ATCC 4352
• Kocuria rhizophilia ATCC 9341
• Lactobacillus
• Listeria monocytogenes
• Mycobacterium terrae
• Oenococcus oenos
• Pseudomonas aeruginosa ATCC 15442
• Pseudomonas aeruginosa ATCC 9027
• Saccharomyces cerevisiae ATCC 2601
• Saccharomyces cerevisiae ATCC 9763
• Salmonella choleraesuis ATCC 10708
• Salmonella enterica ATCC 13311
• Salmonella enterica ATCC 14028
• Serratia marcescens ATCC 14756
• Staphylococcus aureus ATCC 29213
• Staphylococcus aureus ATCC 6538
• Staphylococcus epidermidis ATCC 12228
• Staphylococcus warneri ATCC 17917
• Streptococcus pyogenes ATCC 19615

[DavidCampen]

Phenol is the material that was commonly used in inks, I wonder if thymol might also work. Then there are mildewcides made for latex paint that might work:

https://smile.amazon.com/Trimaco-10152-1-5-Ounce-Control-Additive/dp/B005G8UYFM/ref=sr_1_3?ie=UTF8&qid=1493240504&sr=8-3&keywords=paint+mildew+additive

https://smile.amazon.com/CFI-Products-Complete-Mildewcide-1-5-Ounce/dp/B004KE1GHS/ref=pd_sbs_60_3?_encoding=UTF8&pd_rd_i=B004KE1GHS&pd_rd_r=KRYQAZTFRNA8DB9XYAQY&pd_rd_w=ApB9l&pd_rd_wg=81bD0&psc=1&refRID=KRYQAZTFRNA8DB9XYAQY

Edited April 26, 2017 by DavidCampen

[Jan2016]

I may be wrong, but if you smell KWZ inks, I guess it is phenol they use.

[pjo]

There have been many previous discussions on making iron gall and related inks. From memory the most popular Biocides used for home made inks include phenolic acid , salicylic acid , Dowecil 75, sodium benzoate, clove oil, thyme oil, and a range of commercial fungicides and moss killers, as well as anti-mould paint additives.

 

Most of the cheap and "safe" chemicals used in medicines and cosmetics are also suitable for the purpose and most are stable in acid inks.

 

One of the requirements for the biocide is that it doesn't adversely affect the colour of the ink and doesn't react with the other ingredients to form precipitates. As the biocide is usually less than 1% by volume of the ink it has little effect on the physical properties of the ink.

 

It would be helpful if some knowledgeable member could do a comparison of they many potential chemicals..