[HWY36]

Originally Posted by WaterFarmFan

I decided to get 100% Propylene glycol for my application. RV Antifreeze has a freeze point of 8F, but reports stated that freezes at a slightly higher. The MSDS for the RV Antifreeze states it as:

Propylene Glycol - 25-30%
Water - 64-70%
Glycerol - 4.0-5 mg/m3
DiPotassium Phosphate - 0.5-1%

I think the RV fluid work perfectly fine for your application, but so would 100% PG, which is probably a bit more food safe for incidental contact. Filling up a chest freezer takes at least 20-25 gallons, which is quite expensive. I would say get 100% Propylene glycol and then cut it yourself with water to get the temp range that you want.

WFF

Thx, where you getting you're PG from?

[WaterFarmFan]

Originally Posted by HWY36

Thx, where you getting you're PG from?

Amazon - USP Certified Food Grade 1 Gallon - https://www.amazon.com/Propylene-Gly...dp/B01MS8F1UW/

Was $26 a few weeks ago but now is $30. I checked my label and it is listed at 99.7%

[HWY36]

Originally Posted by WaterFarmFan

Amazon - USP Certified Food Grade 1 Gallon - https://www.amazon.com/Propylene-Gly...dp/B01MS8F1UW/

Was $26 a few weeks ago but now is $30. I checked my label and it is listed at 99.7%

Cool thx. I didn't realize it was that expensive. For that price couldn't I just use Isopropyl? What about the stuff that A6 recommended that's only $65 for 5 gallons?

[WaterFarmFan]

Originally Posted by HWY36

Cool thx. I didn't realize it was that expensive. For that price couldn't I just use Isopropyl? What about the stuff that A6 recommended that's only $65 for 5 gallons?

SDS for Cryo-Tek 100 says 40-60% PG and 60-40% Water (not sure how that works haha), but regardless it is cut with h20.

I am not sure how much volume that you need to cool, but if you only need temps above -20C, I think that you would be able to cut pure PG at least 1:4, so $30 would yield 5 gallons of coolant that is tailored to your exact needs.

WFF

[WaterFarmFan]

As for using Iso, I use this for my baths and traps that need really cold temps. 100% Iso and dry ice cools to -76C. I mix Iso and PG together in different ratios if I want a warmer temp. 80% Iso and 20% PG with dry ice will yield a temp around -55C. 20% Iso and 80% PG with dry ice gives around -35C. You could mix iso or etoh with water, but chances are higher for evaporation.

[G.O. Joe]

Dowfrost, huhm. If anyone wants EG in drums, they may know that the nearest big industrial solvent supplier probably has Dowtherm or equivalent in stock, because that's what industrial size loops use.

[HWY36]

Originally Posted by WaterFarmFan

SDS for Cryo-Tek 100 says 40-60% PG and 60-40% Water (not sure how that works haha), but regardless it is cut with h20.

I am not sure how much volume that you need to cool, but if you only need temps above -20C, I think that you would be able to cut pure PG at least 1:4, so $30 would yield 5 gallons of coolant that is tailored to your exact needs.

WFF

I didn't even see that 60-40, 40-60 monkey business. Didn't think about the 1:4 possibility either, thx.