Silicone O Rings

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Silicone O Rings

Postby M8Harry » Thu Aug 27, 2020 12:21 am

Hi All,

I recently purchased a 23L demijohn from the friendly local Home brew shop and while I got what i wanted it came with an added extra I didn't ask for, a handy tap at the bottom of the basket for decanting.

SO i decided sure this means I can safely and accurately dispense the booze from within to a measuring jug (glass) fur use with Essences or fruits or the likes. (Yes i still use essences but im slowing moving into hybrid washes and im building a mash tun for real all grain goodness)

So i decided to strip this thing down and check it out for safety's sake since i want to store my 94% in it. The hose coming from the glass bottom looks to be sealed in and the hose appears to be platinum cured braided silicone hose (I did a lot of looking on google to be sure to be sure) so after getting the tap assembly apart it has 2 black rubber o rings I want to replace with ones I know are Silicone.

I found a kit of various sizes on amazon and my question to the brains trust is this. Does Red silicone make any difference as opposed to using white silicone?

Here is the tech specs I could find on the amazon page (I wont post a link as im not sure if thats ok or not)

" Silicone Rubber (VMQ) O-Rings Assortment Kit

Circular in shape, round in cross-section, has a durometer of 50A.
This silicone O-rings can be used across a wide temperature range from -22℉ (-30℃) to 392℉ (200℃).
O-rings commonly provide a pressure and fluid seal between cylindrical-shaped, overlapping mating surfaces and are commonly seen in engines, faucets, flanges, valves, and various cylinders.
This silicone O-ring has good resistance to ozone, weather, detergent, salt water, engine and transmission oil, non-petroleum brake fluid, hydraulic fluids that resist fire, vegetable, and animal oils, and high molecular weight chlorinated aromatic hydrocarbons.
Used widely for mechanical sealing, pressure vessel, gas compressor, reaction vessel, heat exchanger, boiler, filter, automobile, electrical appliance, and other fields."

Keeping in mind the quoted text above, would these be ok for use in my application?

Thanks for your time and input.

kind regards

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Re: Silicone O Rings

Postby tubbsy » Thu Aug 27, 2020 7:58 am

EPDM is black and fine for high ABV, so that might be what you already have. Take the o-rings and put into a small jar with your 94% for a week and see if they are still OK. Regular rubber o-rings will start falling apart by then.
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Re: Silicone O Rings

Postby Doubleuj » Thu Aug 27, 2020 6:46 pm

Reading that blurb I wouldn’t use those seals. They don’t sound like food safe.
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Re: Silicone O Rings

Postby OzDistilling » Fri Nov 27, 2020 8:17 pm

EPDM can embrittle over time with >95%ABV. SOme of the pigments used in EPDM formulations I have seen leech into the product. EPDM is cheap.

Silicone is generally OK. The chemistry of silicone once cured is basically all the same. The various grades (colours) is usually an indication of temperature rating or hardness (duro). All distillery temperature ranges are well within all silicones. Silicone does stain, and it does pick up essential oils. Silicone hoses used for gin at 60% can taint neutral spirit.

Viton (a fluoropolymer elastomer) is best for distilleries and ethanol work. Its slightly more expensive, and generally not available in super soft duro's.

BE AWARE there are a lot of crap Chinese seals, hoses, o'rings, etc that claim to be Silicone, that are in fact low density Polyurethane. PU is a no no for ethanol. PU will ignite under a BIC lighter Silicone and Viton will not.
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Re: Silicone O Rings

Postby scythe » Fri Nov 27, 2020 9:33 pm

FYI don't try burning voting seals... they release hydrofluoric acid when then melt and that is nasty stuff.
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Re: Silicone O Rings

Postby chipboy » Sat Nov 28, 2020 12:53 pm

I think that reads Do not burn Viton, Hydroflouric is a rather nasty acid. It kills.
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