ethylene and propylene glycol

[daveandiputra]

just wondering is ethylene glycol that is used for radiator coolant can be used to replace propylene glycol in pyrocat MC?

cheers,

dave

[jochen]

Hello Dave,
I cannot say whether 1,2-propylengycol can be substituted by ethylene glycol. But never use a fully formulated radiator coolant since this contains many other components like amines, borates, some times sodium nitrite, benzotriazole .... mainly as anti corrosion additives for the different metals in a radiator and engine.

[Murray Kelly]

Hi Dave. I have used the anti-freeze concentrate but I chose the one that wasn't lurid green. It is blue and not fluorescent. Hitachi truck anti-freeze MSDS says it's strait eth glycol.

Some, as has been stated have phosphates in and I checked the pH of a dilute solution and it was between 8 and 9. At the concentrations of that developer it probably won't affect the issue but make up a small quantity first so's to be on the safe side.

If pyro is an issue you could substitute HQ for the trial.

Murray

[Gerald C Koch]

Antifreeze contains various rust inhibitors and other additives. So it is not a good choice.

[Murray Kelly]

Indeed Jerry, but some of us don't have the luxury of picking up chems as easily as you in the US do. Here in Oz and Dave in Indonesia have to work around. I have tried unsuccessfully to purchase something as simple as PPD or CD-4 or even propylene glycol or TEA and it is a real hassle. I finally bought at great expense 5L of P glycol and TEA and the latter turned out to be low freezing point TEA with 15% water. It is useless as a water free developer solvent. $56 down the drain!
Another solvent is brake fluid. It's a high alcohol (as you know) and it works pretty well for concentrates.
One gets used to 'work arounds'.

Murray

[Photo Engineer]

Well, I should add here that pH is a meaningless term when you are speaking of water free or low water environments so comments about the pH of antifreeze are meaningless.

Here are some other things to remember:

1. Both Propylene Glycol and Ethylene Glycol taste sweet. (no, I have never tasted them on purpose)

2. Propylene Glycol is safe to use in foodstuffs where a sweet taste and thickening are useful.

3. Ethylene Glycol is deadly poison.

4. Animals and children like the sweet taste and children love the pretty color of EG solutions used in antifreeze.

Have fun. I guess this is another reason not to live on OZ IMHO besides the snakes and spiders! And I thought getting chemistry here in the US was hard!

PE

[Gerald C Koch]

Don't know if this will help but propylene glycol is used to make various liquid medications. TEA is an ingredient in lotions and soaps. You might try what is called in the US a "compounding pharmacy." They do more than just move pills from bottle to bottle. They actually make up medications.

[Murray Kelly]

Hehehehe. Thanks for the endorsement, Ron! I have visited the US many times and the spiders and snakes are quite similar. It's the salt water crocodiles and drop bears you have to watch for here.

I don't think the poisonous nature of the eth glycol is an issue here. I wouldn't like to eat/drink anything photographic actually. The antifreeze (ethylene glycol) is denatured here for that reason and it can often be the only additive. I mentioned the pH when water was added to give an indication of what might be present in the anti-freeze to start with. I know, no water, no pH.

I looked into those compounding pharmacy places, Jerry, but it was even worse than trying to buy boric acid from them. They grudgingly sold me 50g of that. Chemical supply houses are enormously expensive. It's all lab grade and priced accordingly. That's where I got the TEA but didn't check the label until too late. I wrongly assumed it would be 100% coming from that particular source. Grr.

[daveandiputra]

Hi All, thanks for the inputs.

what Murray says is pretty much the truth here in Indonesia, getting chemicals here is not easy. i can get the chemicals that is used by the local industry but most photographic chemicals are not used here. at least that is what i gather from the regular chemical store.

this is the glycol antifreeze i got at home
http://unitedoil.co.nz/wp-content/up...ANTIFREEZE.pdf
the composition only says de-ionized water and the ethylene glycol, but the color is green, any reason it will not work murray?

and about TEA, i just realized you need TEA to make the metol base for pyrocat MC, any way to get around that?

ps: don't worry PE, i'm keeping this awayyyy from children

[Gerald C Koch]

Hi Murray,

I have no idea of what a drop bear is but we do have salt water crocodiles in south Florida. They are doing quite well and have been expanding their habitat. They are, however, very shy and feed on fish. Then there are the alligators which are found all around the Gulf Coast states. They are everywhere and are agressive and will sometimes attack people. It is said that there are more alligators than people in Florida.

There are several companies in the US that sell soap making supples. They sell to hobbiests that make their own soaps and lotions. Anything similar in Australia. I have bought propylene glycol and TEA from one such company here.

Jerry