Electric element caustic cleaning

[DemonBrew]

Caustic Pearl tech and data sheets say not to use it on brass.

Most electric elements in coppers/HLT's have a brass boss which is open to the liquid inside the vessel.

That being the case, what's best to clean them with?
Chlorine cleaner is ok with brass but very expensive.

[dick murton]

Speak to your chemical suppliers about making sure there are sufficient additives to reduce the effect on copper. Don't use unformulated caustic.

Chlorine needs a high pH if you are cleaning stainless steel - above 11, to prevent corrosion of this - so the two are not really compatible.

If you can use a soft brush to get the worst of the heavy muck off the element first, the element should last a fair time. You should be able to find a stainless steel element as a replacement though.

[DemonBrew]

Hi Dick, thanks.

Bit of confusion maybe but it's the boss of the heating element that's brass. There is no copper.
The element part itself is Incoloy 825.

From the specification sheet:
ROD TYPE ELEMENTS: 8mm INCOLOY 825.
THERMOSTAT POCKET(S): 316 STAINLESS STEEL.
TERMINAL BOX: MILD STEEL TO IP66.
PROCESS FIXING: 2¼" BSP BRASS BOSS

Most water immersion type elements have a brass boss hence my question.
The caustic I am using is Murphy & Son's Caustic Soda Pearl, most breweries I know use this or equivalent i.e. caustic soda pearl of some kind.

The details and warnings say:
DO NOT
 Mix with chlorine based disinfectants
 Use on aluminium, zinc, brass or galvanised surfaces

[dick murton]

Brass contains copper though, and is readily attacked in this form. Unfortunately there is no protective coating formed like the chromium dioxide of stainless steel.

I think that pearl caustic soda is virtually pure NaOH, without any additives such as wetting agents or corrosion inhibitors. I haven't used it for ages, but we always treated it as such, and added formulated additves separately.

I am not sure which, if any of the Murphy products (or for that matter most if not all suppliers similar products) would give you the corrosion inhibition you need.

[DemonBrew]

Cheers,

What do you use for cleaning instead of caustic?

[dick murton]

Formulated caustic in the brewhouse, i.e. caustic + additives. Though someone replied recently about using acid successfully. But that would have similar problems, probably worse. You could try, but probably at greater expense, an amphoteric cleaner similar to the type we use in the UK because of having a large aluminium keg and cask population.

Again, consult your local supplier to see what they can get hold of.

[DemonBrew]

Am in the UK myself though have SS casks.

Will speak to suppliers about caustic additives.

Murphy's now supply Holchem products which have more of a range of cleaners, will see what they think.

Cheers

[gitchegumee]

You could also try a sodium metasilicate product, like 5-star's PBW in the states. Next time you replace the element, get a SS boss. Good luck!

[DemonBrew]

Thanks gitchegumee.

Have been speaking to my chemical supplier about this so hopefully get an answer and will post back.

Have you seen how expensive SS bossed elements are

[Rosie]

Hi Demon,

We are in the UK and have really good luck with Spectac G as a caustic based cleaner (with additives). If you are in a hard water area, I'd also recommend adding Divo MR to the mix.

We get all of our cleaners and sanitisers from DBM Food Hygiene...and have had real good service from them Talk to their tech guys for your specifics...details here: http://www.dbm-ltd.co.uk/hygiene/index.html

Cheers,
Jeff

[DemonBrew]

Thanks Rosie,

Will get in touch with them.

If only we could get a supplier of PBW in the uk!

[dick murton]

We are using Spectak G in the kettle in a micro, and the copper elements got chewed up by it. There is now a stainless element fitted - so far so good, but it is only a few months old. Having said that, the original lasted for a number of years - installed way before I got involved.

BTW - No response from Kevin at Murphys yet. I guess he is on holiday. I expect to see him tomorrow night though, so if I remember I will ask.

[DemonBrew]

According to Birko Chemicals in the US, who seem to be the competition to 5-Star, brass is ok with caustic.

Their Substrate Resistance Chart—10% Aqueous Solutions Above 100 °F
suggests that brass has a Good resistance to caustic.

I suppose at the level of caustic pearl I would normally use, 1-2% solution at the approx temps i.e 40C/104F, it should be fine.
It's recirculated and not left to steep as well.

[gitchegumee]

I remember using an iron caustic pump with a brass impeller that lasted for years with every day use. And that impeller was soaked even when it wasn't churning 2% NaOH. AND we also added bleach to the mix--against the advice of your supplier. Sodium hydroxide was supposed to help the caustic with more effective cleaning. It's still used as an additive, although I wouldn't use it any more. And hot caustic/bleach mix did destroy other equipment in the brewery--including SS elements in our keg cleaning machine. That said, there are many flavors of brass... Your supplier may have additives that are not compatible with soft metals. I would try it a few times and pay close attention to any chemical attack. Good luck!

[campbell.brian]

... most breweries I know use this or equivalent i.e. caustic soda pearl of some kind.

Sodium Hydroxide in anhydrous (dry, "pearl," or pellet) form is almost never a built (formulated) product. This is raw caustic with no performance additives.

These products can react exothermically with water. As a result, there is a potential for splattering when added to hot water.

Most breweries in the US use a liquid caustic for many reasons, including safety, automation, and the desire for a built product. However, many liquid caustic products on the market are simply chelated caustic.

Most electric elements in coppers/HLT's have a brass boss which is open to the liquid inside the vessel.

Most newer elements are an alloy simiar to stainless steel--Incoloy, Nickelloy, etc. They may also be a resistive metal with a stainless steel coating. These are fairly chemically resistant.

Speak to your chemical suppliers about making sure there are sufficient additives to reduce the effect on copper. Don't use unformulated caustic.

Listen to Dick. Commodity Sodium Hydroxide is not a cleaner. It is a raw material in caustic cleaners. These caustics will be cheaper on a per-gallon basis. However, these products will be considerably more expensive on a bottom line when considering efficacy and usage concentrations. You will use more product, put more caustic down the drain, and ultimately spend more money on unbuilt products.

Unformulated caustic relies solely on alkalinity. Typical usage concentrations necessary for brewery CIP are 2-5% Sodium Hydroxide, or 4-12.5% by volume of product. Built caustics are recommended at 1-3% by volume, or only 0.3-1% Sodium Hydroxide and will still provide superior results to commodity caustic.

It is very easy to inhibit caustic solutions against copper. The LERAPUR 283 CI is a built caustic that is inhibited against copper. The LERAPUR 39 is a copper inhibitor that may be added to caustic solutions to copper-inhibit them. Performing cleaning on copper equipment with caustic that is not inhibited will corrode copper and lead to premature equipment failure.

The LERAPUR NC (NC for Non-Caustc) is a Sodium Metasilicate-based powder product very similar to the aforementioned alkaline homebrew cleaner available in the US.

Chlorine needs a high pH if you are cleaning stainless steel - above 11, to prevent corrosion of this - so the two are not really compatible.

Listen to Dick. I recommend chlorinated caustic on Stainless Steel for about 1% of applications. This is never related to the performance of the caustic--as oxidation can now be achieved without the use of chlorine or the risk of damage to Stainless Steel equipment. Also, Chlorinated caustics may never be reused, such as inside of a keg washer or CIP station. This is not a question of if, but when equipment will fail due to chloride stress corrosion.