PDA

View Full Version : Cast Iron Pot Flatness



electrosteam
20th Jul 2017, 09:29 AM
I have an induction single coil portable cooking appliance from Ikea.
At $59 it is great value and it seems to work fine, destined for our on-site caravan.
The only down side is it only has 9 heat steps, with steps 1 and 2 a bit too big.
The cooking surface shows nice reflections so is acceptably flat.

Then I got a 200 mm lidded cast iron pot for doing stews on the appliance.
Problem is, the pot is slightly dished on the bottom making it unstable when using utensils to stir.

Should I attempt to flatten the bottom ?
Lathe, mill, grind, lap or scrape ?

This a brand new pot and has not developed any patina.
I have access to an open fire place occasionally, my plan is to use this to add some external patina.
Any suggestions on an external coating prior to the flames ?

368851

John

Retromilling
20th Jul 2017, 12:57 PM
You could mill the base flat but holding the pot down will be an issue . You could clamp on the handle tabs but cast iron can be very brittle when it's thin so I would be inclined to put blocks under the handle tabs and clamp down on that so it's held in place but the tabs are note being bent down.
Might vibrate a bit but take light cuts . It only has to sit flat so it don't wobble. The induction heating does not require firm even contact like ordinary electric elements do. Bit of work with an angle grinder and a straight edge might suffice.

Harry72
20th Jul 2017, 11:47 PM
I reckon just give it a good walloping with a hammer:evillaugh:

Retromilling
21st Jul 2017, 11:29 AM
It's cast iron it could just crack or even shatter .

electrosteam
21st Jul 2017, 07:33 PM
Scraping with an angle grinder (carefully) sounds attractive, a hollow in the centre would not affect the heating by the coil.
John

russ57
23rd Jul 2017, 09:28 PM
Brand new pot? Take it back... It should be slightly hollow if not flat...


-russ

electrosteam
24th Jul 2017, 10:06 AM
Unfortunately, I can't take it back as it is a gift from a van site neighbour.

I have done some work on it.
My angle grinder was not available, so I used a Dremel clone to grind out the centre section.

Then, a fatal mistake.
I blued up the granite, tested it for flatness, and put in a couple of scraping cycles.
Hooked. More cycles of test/scrape/test, then stop for the evening.
Perhaps more cycles to come !

A test on the appliance still shows a slight rock, not evident on the granite, so a check on appliance flatness is planned.

368911

John

Oldneweng
24th Jul 2017, 07:14 PM
So are you going to scrape the appliance?

Dean

electrosteam
24th Jul 2017, 07:27 PM
Dean,
I wish !

The appliance is light and flexible, it could be I just have to find a flat surface to sit it on.

John

electrosteam
25th Jul 2017, 10:37 AM
The first test stew will be at home with the appliance on the kitchen bench.
When the pot was tested in this location - no detectable rocking, flatness problem solved.
If necessary in the van, I can make up a dedicated shim

Now to try and get a used patina finish.

John

electrosteam
25th Jul 2017, 04:24 PM
The pot at the end .....

Photo shows first bean stew.
Olive oil, carrots, onions, capsicum, red kidney beans, celery, red wine, water.
No salt, sugar, stock or any other flavourings.
To be used tonight as a side dish or potato topping.
Wife even commented on the lovely aroma when she got back from her swim.

Pot is impressively stable when stirred with the wooden spatula.

368931

John

russ57
25th Jul 2017, 08:28 PM
Win!



-russ