Copper clad cast iron

[Dustonthebottle]

So I have an idea of joining a copper sheet to a cast iron pan using diffusion welding/mokume gane. The purpose would be to help with heat transfer across the pan. I am looking for thoughts, ideas, concerns.... Any input would be greatly appreciated. I doubt this will be a project I tackle any time soon but it is something I am researching. 

Thanks

[ThomasPowers]

What temperatures are you looking at?  Is this really needed?  Why not use a tin lined copper pan or a stainless pan clad in copper?

[Dustonthebottle]

I love cooking on cast iron but heat transfer to the edges of the pan is really poor. Especially on larger pans. 

[ThomasPowers]

Why not get a thick slab of copper and put that on the stove and place the pan on it knowing the whole surface will be close in temperature and so not a hot spot over the flame and cool edges? (This is assuming a gas stove and so a thick slab will be offset from the top of the stove---or if you could find a blacksmith they could forge a trivet to hold the copper slab stable above the burner...)

[Dustonthebottle]

A thick slab of copper would indeed work.  I am not assuming this would be an easy task and I am not saying it is not something that couldn't be solved an easier way but it is something that I really want to accomplish. I figure a 100% bond that is flawless is not necessary. I just want to permanently bond a piece of copper to a cast iron pan. 

[ThomasPowers]

"Just because I want to" is a perfectly good reason. We get a lot of people that are trying to accomplish a particular task in the hardest most expensive way possible that really don't care about the how but in the results and so knowing what you want to accomplish as well as how you plan to do it helps

If the two pieces are very well fitted; some silver braze and a furnace brazing heat come to mind.  I'm a big fan of cooking on cast iron myself and rescue old skillets on a regular basis.  I'm cleaning them down to bare metal using the lye method rather than the burn off method---no chance of warping the skillet that way.  My wife likes her super newfangled coated skillets that can't be heated enough to properly cook a lot of stuff or the cooking takes 4 times as long.  When she's down at the casita she has to use *my* pans!

[AnBello]

This seems like an interesting topic. I look forward to seeing your results!

[Dustonthebottle]

When I want to clean an old cast iron pan I use a battery charger and baking soda/water solution lye works too but I just don't like how nasty it is. 

[CoolCopper]

I love to cook on cast iron and I also used to do brazing with oxy-acetylene or oxy-propane torches.  (I built a couple of bicycles like that.)  I have copper wire and I have found that copper can be "brazed" onto steel using flux and the gas torch in the same way that I can braze with brass.  So I would think that one could take a cast iron skillet and place it upside down in the right furnace.  Use brazing flux and copper to "braze" the copper onto the base of the skillet.  Some added wall might be needed to prevent the melted copper from flowing off the bottom of the skillet.  Maybe this could also be done with a hand held gas torch if the skillet did not crack from uneven heat and if the copper could flow flat enough.  Brazing is like soldering; the iron base metal dissolves slightly into the molten metal at the metallic boundary so it is a very tight bond.

[Les L]

Dustonthebottle, I think you are trying to do a lot of work that is not going to fix the problem. Why is your heat not transferring to the edge of the pans? You’re burner is not large enough. I cook Almost every day with some type of cast iron pot, from 8 qt to 25 gallon. I have approximately sized burners under each and will not consider trying to do something to my pots to improve them