Preservatives for carbon Glop

[Rick A]

I'm having a slightly difficult time finding out about thymol. First, do I even need a preservative in my glop? If so, where do I find thymol? I searchthe web and when I google the word I get Thyme oil, but which, red or white? Can I substitute tea tree oil instead? Can I use Listerine, and if so how much? Do the other ingredients in Listerine have any effect on the glop? I can't get Thymol at my local pharmacy, when asked, they just give my that vacant glazed over stare.

 

[paul_c5x4]

Thymol is used to control varroa mites in bee hives - Have a look for local bee keepers or apiary supplies.

One word of caution - Use gloves when handling thymol, if you get it on your skin, it will sting.

 

[gmikol]

You might also try a "natural wellness"/"hippie" store, or even Whole Foods, if there is one in your area. It's used as a "safe" surface disinfectant, as opposed to bleach or triclosan. I think I saw Thymol at my local Whole Foods, but they've since scaled down that section.

--G

 

[Rick A]

Thanks for the Whole Foods tip-the nearest one to me is --oh --about 150 miles. But there is a (or used to be) a GNC about 50 or so miles. I know someone that is a bee keeper, I'll check with him for some.

 

[Vaughn]

I do not use preservatives in my glop. I generally mix it up in the morning (water, wait, sugar and pigment), let it sit in a 110F waterbath (with an occasional stir with a magnetic stirrer) for 6 to 8 hours, pour all the glop that evening and start the drying of the tissue with a fan on them for 12 hours (overnight), and w/o fan for another 12 hrs -- then the tissue can be stacked (with space in between each) and used over the several months. But if I do not use a fan on the freshly poured tissues for that first 12 hours, my tissue can become mold farms. Once the surface is dry, the mold seems less likely to attack the tissue. Room temp 60 to 70F, Rh of 60 to 70%.

If you want to keep the glop in the fridge, want to hold it in a waterbath for a day or so, or not have to worry about a fan blowing on the tissue while drying, or if you live in an environment filled with mold spores, then a preservative would be worthwhile.

 

[RowanBloemhof]

Well to be honest i havent found the need for any preservatives yet. I once made a batch of glop that was stored in the fridge for well over 3 weeks. It didnt spoil at all. What i personally did is add some alcohol prior to letting it cool, and making sure all the air was out. I think letting the air escape before cooling helps alot as this makes the glop pretty much an anearobic emulsion. Forming quite an inhospitable place for bacteria and or mold. The sugar aides in that as well.

The only real downside to storing the glop for a longer period is the fact that gelatin gets stronger as it sits. And in my experience this seems to stay this way even after reheating/melting. If this is beneficial or not im not to sure about.

However if you really feel you should use a preservant. I did use Aspirin once to preserve gum arabic. Just make sure you buy aspirin without any flavour additives. Dissolve an aspirin in say 50ml of water and strain it before adding it to your glop, or in my case gum arabic. Of course calculate this 50ml of water in your final recipe. Often the filling material for pills is gelatin or starch. Both which shouldnt really interfere with the characteristics of your glop.

 

[Hexavalent]

A few drops of Dequadin oral paint (from a pharmacy) works well. Using boiled water, and keeping containers and implements scrupulously clean a.k.a. "clean lab technique" is always good practice - if there are no "bugs", they can't grow.

 

[Rick A]

My house was built in the 1880's and sits on a hand laid stone foundation, my basement is always damp in spite of continuously operating a dehumidifier. I have mildew in the basement and I'm sure the mold spores are present everywhere, as witnessed by my allergic response to it on a daily basis. Twice a year I spray my basement walls with disinfectant and mildewcide, I just want to be sure mold doesn't attack my prints or glop, I get teased about being 'cdo' (just like ocd except in alphabetical order like it should be) about my dark room procedures. I really am not a germophobe, I just hate throwing money away needlessly and really don't like when my supplies get ruined if I could have prevented it.

 

[tripgr]

I've used sodium benzoate in my gum arabic solution at a rate of 1% of dry weight of gum arabic. I used the gum in my gum prints. The gum solution, stored at room temperature away from direct light remained unchanged over many months. I am just starting in carbon and have taken the same approach to preserve glop. Can't yet confirm benzoate as an efficiency glop preservative, but can't find a reason to suggest it would not do the trick. I did see thymol sold by some Amazon vendor, but since there was no delivery to Canada and I have a lifetime supply of sodium benzoate on my hands...


Gregory

 

[Andrew O'Neill]

I don't and never have used preservatives in my glop. I make it, let it gas out over night and use it all to make tissues in the morning.... 24 hours later, my tissues are ready.

 

[Photo Engineer]

The Photographers Formulary sell it as a solid. Mix it in undenatiiured alcohol at 10% or 10g in 90g of alcohol. This is a weight/weight solution. Use it at about 5 drops per 100 - 200 g of glop. If you ask Sherry at the Formulary, she can send you a full instruction sheet if they still have them as handouts.

Don't let the solid or solution hang around long in the open. Thymol will evaporate.

PE

 

[Jim Fitzgerald]

Best to mix it, pour it and be done. Make it and use it same day or let it out gas over night and pour in the morning.

 

[tripgr]

Follow-up to my earlier sodium benzoate-as-a-glop-preservative post. I'll second Jim's advice. My pure gum solution is holding stable. Unfortunately, mixture of the same gum solution and ivory black, which was to be used for future glop mixes, did not. The pigment mix fermented. As I opened the bottle containing the pigment mix I was met with a spray of frothy black mess accompanied by an evil stench. Will not repeat.


Gregory

 

[pschwart]

Sounds like most of the carbon printers who replied don't use preservative. I have never used any either -- I can store glop in the fridge in my garage for months with no signs of mold. I have *never* seen moldy tissue. I'd say don't bother unless you are seeing a problem with moldy glop or tissue.