Why do pyrolytic ovens require the removal of metal racks for cleaning?

[sophiecentaur]

TL;DR Summary

Why do you need to take out the furniture and racks during pyrolytic cleaning

I just tried cleaning our new oven with the pyrolytic function. Incredible results and it certainly warmed up the house.

But the intructions insisted that I remove all metal racks etc. I have to wonder why, bearing in mind that the temperature can't melt the stainless steel. This increases the effort from minimal to annoyingly much. Would the heating affect the silvery finish of the S/S or could it possibly affect the strength?

Having scolded someone about not making an effort to research a topic, I'm a bit reluctant to post this question but the videos and text that Google offer me are all about the how's and not the why's.

The temperature of the oven seems to be lower than what could affect t S/S (?).

 

[renormalize]

From Samsung:

• We do not recommend leaving the oven racks in the oven during the self-clean cycle. The racks may warp and discolor due to the extreme heat created during this cycle. The racks can also damage the rack guides of the porcelain oven cavity due to expansion and contraction.

 

[sophiecentaur]

From Samsung:

• We do not recommend leaving the oven racks in the oven during the self-clean cycle. The racks may warp and discolor due to the extreme heat created during this cycle. The racks can also damage the rack guides of the porcelain oven cavity due to expansion and contraction.

From the horse's mouth, as they say. Thanks.
I guess a suitable metal for the oven contents would triple the price.

I wouldn't mind a change of colour but warping could be an embarrassment.

 

[TonyStewart]

+ SS cleaner & microfiber dry wipe

 

[sophiecentaur]

From the horse's mouth, as they say. Thanks.
I guess a suitable metal for the oven contents would triple the price.

I wouldn't mind a change of colour but warping could be an embarrassment.

 

[pbuk]

But the intructions insisted that I remove all metal racks etc.

Same with ours. I did that the first time but never since.

The racks may warp and discolor due to the extreme heat created during this cycle. The racks can also damage the rack guides of the porcelain oven cavity due to expansion and contraction.

This has not happened. Yet. YMMV.

 

[sophiecentaur]

Same with ours. I did that the first time but never since.

This has not happened. Yet. YMMV.

That's nice to know.

I guess the distortion could be taken care of if the mounting holes / slots are designed generously. It's not absolute expansion here but differential expansion, compared with the oven body that counts. There's the problem. I imagine that the steel of the oven must have been chosen to match the enamel or there would be cracking under normal thermal cycling. This wiki link has a list of typical expansion figures. I'm sure the designers used similar information - steel to match the enamel being more important than matching stainless steel.

Probably Smeg (and the other manufacturers) are just covering their backsides. We have to wait for more input from PF about experiences. If it still looks risky, I might remove the grot on the metalwork with a blow torch, carefully applied.

But what a potential selling point to offer a self cleaning oven that looks after itself!!

 

[pbuk]

We have to wait for more input from PF about experiences.

Probably better forums for this: in the UK we have Mumsnet. Some reports of damage there.

 

[Tom.G]

I don't know about currently manufactured ovens, but the older ones (without fancy "coatings") had a rather convenient approach to cleaning, even the gas ovens.

Heat them up to their maximum temperature, then, using a pump squirt bottle (spray bottle set to 'stream'), squirt the heavy crud layers with water. The steam explosion and sudden temperature change does an amazing cleaning job.

You would probably want to remove the racks first just to get them out of the way.

Have Fun!
Tom

p.s. Probably want to avoid the heating elements/burner. I haven't damaged any yet but ...

 

[sophiecentaur]

Probably better forums for this: in the UK we have Mumsnet. Some reports of damage there.

A good suggestion except that their posts didn't discuss any actual Science. No one actually said that being naughty caused any breakage - just slightly discoloured shelves.

I did learn the idea of using the dishwasher for the S/S furniture. I also got the message that sloppy people, who wait a long time between cleanings, suffer from a stinky kitchen whilst the self cleaning is in progressing. Serve 'em right, I say.

The inside ends up looking like a brand new oven.

 

[sophiecentaur]

The steam explosion and sudden temperature change does an amazing cleaning job.

I wonder if the thermal shock could be damaging the enamel surface. I guess there's not a big temperature change below the surface and the coefficients of thermal expansion will be chosen to be similar.

From your description, it sounds like you have your underpants on outside your trousers.

 

[Tom.G]

From your description, it sounds like you have your underpants on outside your trousers.

Ah well, I guess it all depends on whether you want to be 'practical' or 'conventional.'

 

[old school chemistry]

A suggestion re racks. i put all racks and any enamel oven trays I want to clean in a tough plastic bag (eg garden bag), pour in a couple of tablespoons of ordinary household ammonia, and close the bag. Leave for a day or so. The ammonia vapour saponifies the grease, which then comes off the racks etc nicely in the dishwasher. You can use the bag again and again, to save wasting more plastic.

 

[sophiecentaur]

A suggestion re racks. i put all racks and any enamel oven trays I want to clean in a tough plastic bag (eg garden bag), pour in a couple of tablespoons of ordinary household ammonia, and close the bag. Leave for a day or so. The ammonia vapour saponifies the grease, which then comes off the racks etc nicely in the dishwasher. You can use the bag again and again, to save wasting more plastic.

Actually, the pyrolytic cleaning takes no effort so I tend to do it more frequently. Hence the racks are cleaner and the grot tends to soak off in the sink with just washing up liquid. In the old days, I used a heavy duty oven cleaner and they supplied hefty bags to do your trick with. Single use, of course.

I considered risking the racks in the oven but warping could be a problem, soluble only with a good flat surface and a big hammer (and crossed fingers).