Hi, I've made a couple of knives via stock removal, and I want to try my hand at forging one. I'm planning on building a wood forge using a gas grill lid. I'm using wood because I have an unlimited, free supply of it, and coal is hard to get cheaply in my area. I know that wood has a number of drawbacks, like it has to burn a while to get the coals burnt down to forge with, but I'm still going for it.
My question is this, do I need to line the inside of the grill lid with firebricks? I'm 90% sure the lid is stainless steel, and I'm using black iron pipe with holes drilled in it for the air supply. Most of the coal forges I've seen don't have firebricks or insulation, but there's also usually a huge bed of coals which I'm assuming provides insulation. Will the forge get hot enough without firebricks to forge with? Or will the stainless steel get too hot and deform causing the whole thing to fall apart? I know Whitlox's wood forge uses kaowool and firebrick for insulation, which makes me wonder why wood needs insulation, but coal doesn't.
On a side note, I know coal forges need a hole in the bottom to push the burnt ashes through, should I cut a hole in the bottom beneath the air supply pipe for the wood ashes to fall through?
I'll probably have more questions coming.
Thanks for the help,