View Full Version : Help-Mildewcide for pastel making

09-18-2010, 01:43 AM
Does ANYONE know where I can purchase an anti fermenting preservative for use in making pastels? Or ANY preservative for this purpuse. Man, I thought you could find anything on the web, but I guess some things are still out of reach. That, or they just don't provide enough information to know whether or not their products are anti fermenting. Not sure what anti fermenting is, so please don't ask me. I'm assuming it means that something is not prone to fermenting. The hamster had to run extra hard in his wheel to come up with that deduction. I normally wouldn't be so concerned about mildew, but we live in a very humid part of the country that is plagued with mold and mildew problems. I've tried all of the art suppliers, pastel suppliers/manufacturers and most hardware stores with very limited success. Does anyone out there actually make their own pastels with this type of preservative, and know where I can purchase it? Any help would be just great. Thanks in advance.

louis bishop
09-18-2010, 01:54 AM
I've made my own pastels for years, live in a very humid area, and have never had a problem with mildew (assuming that's what you meant by fermenting). Although I have been warned about it, I always figured I'd use them rather quickly. Some I've had 6 or 8 years with no problems and no mildew. All I use is a mixture of gum tragacanth and water, formula depends on pigment and hardness desired. I do use ample amounts of talc on my hands to prevent too much sticking. Hope that helps.

09-18-2010, 01:59 AM
Fantastic!!! Thanks. What is the actual direction to go in with the Gum T. Is it more for harder pastels and less for softer ones? I know each pigment requires a certain amount, but generally speaking, what is the correct rule of thumb?

louis bishop
09-18-2010, 02:18 AM
I've made up batches of gum trag. I've kept for years, and would have to look up the formula. I think you can get it almost anywhere. I use 5 containers and mark them 1-5, making my strongest solution #1, and cutting the strength of the solution in half for each container. I'm almost always using #3 for a soft to medium soft pastel. You might also get some precipitated chalk if you haven't already.

09-18-2010, 02:28 AM
Thanks for the info, I've got the gum t., what I'm wondering, using your formulations, do you then use a #1 to make a hard pastel and a #5 to make a very soft pastel, or the other way around?

louis bishop
09-18-2010, 02:32 AM
#1 is the most concentrated, and the hardest. Like a rock. I usually use 2 and 3.

09-18-2010, 02:48 AM
Got it. Thanks Louis. I appreciate all of your help. I've got the pigments, chalk, talc, and gum t., and I'll give it a go without the mildewcide. I'm surprised to hear that the prepared gum t. lasts that long; that's good news though. Again, thanks for your help, you've saved me a whole lot of web searching. Take care.

09-18-2010, 04:12 PM
Hi - if you can get it, you can possibly use camphor oil - I used a bit of champo-phenique that has a good percentage of it and it worked pretty well and didn't have an offensive odor like some other mold inhibitors. Maybe that might work for you.

09-18-2010, 09:56 PM
Thanks Paula, I'll give it a go if mold peeks it's ugly head. I Appreciate your time and help.

09-19-2010, 08:49 AM
I've used a drop or two of clove oil in my gum trac mix or a drop of barbicide in my water when I'm only using water as I don't have easy access to distilled water unless I make it myself - which takes ages and leaves it open to the air as I no longer have the equipment.
I don't actually use much gum t as water alone is enough in many cases.

10-30-2010, 08:23 AM
Hi folks
Fantastic to find this thread!
I live in the UK and there's not a lot of info' here with regards to making your own pastels. I have just made a small batch of Titanium white sticks which have turned out very brittle. I can only assume that this is because I did not use Gum Tragacanth.The strange thing is, I made a few sticks of another colour (tinted with T' White) a few days ago and they were quite a bit softer. Any ideas why ??
I kept my formula simple,as recommended on a US website.The formula being: Pigment / Calcium carbonate & Talc. The water I use is just from the tap (faucet) then filtered through an ordinary Brita filter. I can get distilled water (very expensive) but my logic says that as soon as you take the lid off, the quality of that water is compromised ?
Any advice would be most welcome !
Hope to hear more on this subject.
Big thanks

the drover's dog
10-30-2010, 08:52 AM
Howard, I'm no expert, but the thought ocurred that you might be able to dissolve in water, a portion of one tablet that is used to prevent moulds in bottles that are washed for home brewing and to clean the brewing kit before starting a new batch. Yeasts used in brewing are moulds. I'm pretty sure they are a harmless sulphur compound of some sort. Similar product can be used to sterilize babies bottles. These kill moulds and if used in too high a concentration will even inhibit the normal brewing process.

Just a thought if you don't want to use too much gum tragacanth which I believe can make your pastels quite hard if used in too great a quantity.


10-30-2010, 09:44 AM
Many thanks Dale
The brewers cleaning tablet sounds good ! Do you suggest that I use this instead of GT ? What is the purpose of adding Gum Tragacanth ?
My pastels are very brittle without the Gum Trag. I get the impression that the less Gum Trag you use - the softer the pastel stick will be ? If that's true then my pastels should be very soft as I am not using GT.
I suppose my problem is, I want to make soft pastels rather than hard ones.
Thanks again Dale
Very much appreciated !

10-30-2010, 11:20 AM
Hi Howard, welcome!

Gum T is the binder (same as in watercolour, I think, or is that Gum Arabicum?). Some pigments are hard in themselves, others are soft. Some pigments bind to each other better, some not.

A very common recipe for binder solution is to make 5 batches of diminishing strenght, for different pigments. At the moment, I can't find my link to a good instruction on the web, will be back if I do find it.

10-30-2010, 04:35 PM
Thanks Charlie
I think your advice that some pigments produce harder sticks than others is correct. But it makes me wonder how my store bought white pastel sticks are much softer than mine - Trade secrets I suppose !
I'll experiment with some other ingredients.

10-30-2010, 05:11 PM
Howard, they often use white chalk as a white pigment for white sticks, as it is softer.