Domestic Chemistry

[Michael GilliganParticipant @michaelgilligan61133]

Posted by BC Prof on 14/04/2022 12:23:45:

it's Ideal to[pic for the tea room .

Brian

.

Perhaps it is … now

[ please note my response to Dave Halford ]

MichaelG.

[Grindstone CowboyParticipant @grindstonecowboy]

Posted by SillyOldDuffer on 14/04/2022 09:44:50:

Anyone tried Isopropyl alcohol? Apart from the cost, fumes, and fire hazard I think it might work well. Ditto petrol…

Dave

Tried IPA, didn't work as well as expected.

Rob

[Robin GrahamParticipant @robingraham42208]

Posted by SillyOldDuffer on 14/04/2022 09:44:50:

Posted by Robin Graham on 14/04/2022 01:01:26:

Posted by Michael Gilligan on 13/04/2022 19:33:38:

Thanks to Dave and Thor … I am reminded of a previous thread on this forum, about micro-bubbles generated in canine toothpaste.

I am happy to believe that the underlying process is generally similar.

MichaelG.

.

Ref. **LINK**

Edited By Michael Gilligan on 13/04/2022 19:36:14

…

On the chemistry front I'm pretty skeptical about claims that vinegar 'attacks' grease in a chemical way. It's certainly true that grease can be broken down by dilute acid (acid hydrolysis of esters), but I doubt that the reaction is significant in cleaning an oven. Possibly it has some mild solvent action?

…

That's what I was hinting at when I said the answer was as much to do with physics as chemistry. Dilute Acetic Acid isn't like Caustic Soda, which attacks fats aggressively; Vinegar only has a mild dissolving effect. Simply splashing vinegar on a dirty oven won't get it clean. It's important that the Bicarbonate / Acid mix be a paste, in which the Bicarbonate and Acid are slowly reacting to produce micro-bubbles, AND there are plenty of sharp Bicarbonate crystals to act as an Abrasive, AND there's enough fluid to penetrate tiny cracks and crevices, AND the paste is rubbed in enthusiastically by the operator. Works in much the same way as soapy Brillo-pad, except the Brillo pad abrades with steel-wool, soap breaks up the fat and there are no micro-bubbles.

Cleaning an oven with a solution of Sodium Acetate made by carefully neutralising Sodium Bicarbonate with Vinegar is a waste of time. It's not reactive or abrasive and there are no micro-bubbles.

Caustic Soda paste, made with water, can be splashed on and left. The alkali breaks fats up, so the operator can leave the oven to soak and wash the whole lot off with water a few hours later. Sodium Bicarbonate would do the same but take a lot longer.

Anyone tried Isopropyl alcohol? Apart from the cost, fumes, and fire hazard I think it might work well. Ditto petrol…

Dave

Apologies for not referring to your post directly Dave – I think you nailed it when you said it is as much to do with physics as chemistry, Perhaps even 'more' rather than 'as much'? As Michael had asked for an explanation of the chemistry I was attempting to give some background as to why a chemical explanation doesn't work by referring to the chemical basis (ester hydrolysis) for fat breakdown by the individual components of the mixture.

IPA is good for many things, but being a polar solvent isn't great for grease, as Grindstone Cowboy found. Ideally one would use dichloromethane or chloroform for pure solvent action, or a solution of sodium dichromate in

concentrated sulphuric acid for pure chemical action.

I'm not sure how one would make a paste of caustic soda in water? Sounds a bit dangerous…

Robin

[Mark RandParticipant @markrand96270]

Posted by Robin Graham on 15/04/2022 00:23:56:

I'm not sure how one would make a paste of caustic soda in water? Sounds a bit dangerous…

Robin

Isn't that what morern paint strippers are?

Of course, the ones that actually work still have dichloromethane as a major constituent. Hadn't thought to use one as an oven cleaner though.

[BazyleParticipant @bazyle]

Given that ovens are used at >100c which will kill all microbes why clean it anyway? Unless you are using it for its proper purpose, ie baking enamel paint then I can see the need to ensure there are no sources of smuts

[An OtherParticipant @another21905]

I've always found the most efficient method is to let the wife do it (she is usually the one that makes it dirty anyway)

[Author]

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