Oil in herms? Anybody here do it?

[Kingy]

My system is up and running im just ironing out a few minor problems which have been sorted and im left with my hex. I cant believe i didnt think of it but i made it out of a small fire extinguisher.
I empty it after every brew and black **** comes out as the inside rusts between brews.
So i was thinking of putting oil in there.
Has anyone done this before?

 

[Yob]

Like.. Olive oil?

 

[QldKev]

You don't want to increase the thermal mass of it, so I would not. I would look at painting it in a heavy paint or waterproof membrane.

 

[Black Devil Dog]

I'd be taking it to the scrap metal yard.

 

[sponge]

I'd grab an $8 kettle from woolies.

 

[dicko]

If rust is a problem you may try glycol or antifreeze mix rather than oil.

Many years ago a white coloured oil similar to cutting oil was mixed with water in car and truck radiators to eliminate corrosion of steel welsh plugs that were common in older automotive engines.

Better still just use a stainless steel vessel in place of the fire extinguisher....

 

[Yob]

Fill it with never wet

 

[tugger]

It's superhydrophobic.

 

[krausenhaus]

You don't want to increase the thermal mass of it, so I would not. I would look at painting it in a heavy paint or waterproof membrane.

Oil has a lower specific heat capacity than water so thermal mass would actually decrease.

But yeah, I would probably look at sealing it or throwing it away instead.

 

[Yob]

He's talking HERMS not RIMS right? WGAS if the vessel is a bit rusty, it's the inside of the coil that needs to be clean yeah?

Agreed it's nice to have both shiny says the man using a 5lt SS Birko urn..but it ain't the end of the world if the vessel is a bit tarnished as long as the coil is sealed

 

[krausenhaus]

I think it's more about stopping it from corroding through by not keeping it wet the whole time.

Looks like this has actually been discussed here before..

http://aussiehomebrewer.com/topic/38466-rimsherms-hybrid-heating-chamber/

 

[booargy]

I have a 5l boiler that is jacketed and filled with oil. The temperature difference can be increased to get the boil rate I want and it works well without pressure. To get 150c with steam you need around 13mpa.

 

[QldKev]

Oil has a lower specific heat capacity than water so thermal mass would actually decrease.

But yeah, I would probably look at sealing it or throwing it away instead.

Thanks for that pickup. I just assumed it was the other way with oil being denser, but it doesn't work out that way.

 

[Kingy]

Thanks for the ideas neverwet should never be sold lol. Think i might try the oil idea anyway. I wont have to drain it for a few brews it should clean it up a bit hopefully to. It works great so itd be a shame to just toss out. Its gunna be a while before i get to spend any more money on the brewery.
Now the question is sunflower? Canola, vedgetable lol.
Im pretty sure food grade glycol wouldnt have a rust inhibitor in it.

 

[TheWiggman]

If you pour oil in water Kev does it sink or float to the top? That'll tell you which is denser

 

[Kingy]

So ive been studyin a bit on this and the only reason i can see this not working is because of the density of the oil and the potential to overshoot temps when ramping due to the oil taking longer to cool. Im gunna run a few tests with differant food grade oils to see how it pans out.

 

[QldKev]

Did you read all the responses? Cause I've just learnt that oil could actually be a better medium than water.

 

[nathan_madness]

Yeah, tried it with Peanut oil. It's not good. Some points that I noted:

• Oily stench when hot
• Any slight moisture or water crackles and pops
• Does not heat in step mashing as fast as water
• PITA to clean off all HX bits if you need to strip down

I was using it to see if it would heat faster and also not evaporate. I used peanut oil as it is one of the thinnest oils.

 

[Kingy]

Did you read all the responses? Cause I've just learnt that oil could actually be a better medium than water.

yea my thinking is to believe that the oil would hold its temp longer once i hit my target mash temp. Once the element turned off the oil would continue to raise the wort temp before it equalized.
I'll do a few tests using differant oils but i reckon itll be ok

 

[dicko]

yea my thinking is to believe that the oil would hold its temp longer once i hit my target mash temp. Once the element turned off the oil would continue to raise the wort temp before it equalized.
I'll do a few tests using differant oils but i reckon itll be ok

Kingy,
I would have thought that a quality PID controller would prevent that happening!